/src/gdal/ogr/ogrsf_frmts/shape/shapelib/dbfopen.c

Source
/******************************************************************************
 *
 * Project:  Shapelib
 * Purpose:  Implementation of .dbf access API documented in dbf_api.html.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 1999, Frank Warmerdam
 * Copyright (c) 2012-2024, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
 ******************************************************************************/

#include "shapefil_private.h"

#include <assert.h>
#include <errno.h>
#include <math.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>

#ifdef USE_CPL
#include "cpl_string.h"
#else

#ifndef STRCASECMP
#if defined(_MSC_VER)
#define STRCASECMP(a, b) (_stricmp(a, b))
#elif defined(_WIN32)
#define STRCASECMP(a, b) (stricmp(a, b))
#else
#include <strings.h>
#define STRCASECMP(a, b) (strcasecmp(a, b))
#endif
#endif

#if defined(_MSC_VER)
#if _MSC_VER < 1900
#define snprintf _snprintf
#endif
#elif defined(_WIN32)
#ifndef snprintf
#define snprintf _snprintf
#endif
#endif

#define CPLsprintf sprintf
#define CPLsnprintf snprintf
#endif

#ifndef FALSE
#define FALSE 0
#define TRUE 1
#endif

/* File header size */
#define XBASE_FILEHDR_SZ 32

#define HEADER_RECORD_TERMINATOR 0x0D

/* See http://www.manmrk.net/tutorials/database/xbase/dbf.html */
#define END_OF_FILE_CHARACTER 0x1A

#ifdef USE_CPL
CPL_INLINE static void CPL_IGNORE_RET_VAL_INT(CPL_UNUSED int unused)
{
}
#else
#define CPL_IGNORE_RET_VAL_INT(x) x
#endif

/************************************************************************/
/*                           DBFWriteHeader()                           */
/*                                                                      */
/*      This is called to write out the file header, and field          */
/*      descriptions before writing any actual data records.  This      */
/*      also computes all the DBFDataSet field offset/size/decimals     */
/*      and so forth values.                                            */
/************************************************************************/

static void DBFWriteHeader(DBFHandle psDBF)
{
    unsigned char abyHeader[XBASE_FILEHDR_SZ] = {0};

    if (!psDBF->bNoHeader)
        return;

    psDBF->bNoHeader = FALSE;

    /* -------------------------------------------------------------------- */
    /*      Initialize the file header information.                         */
    /* -------------------------------------------------------------------- */
    abyHeader[0] = 0x03; /* memo field? - just copying */

    /* write out update date */
    abyHeader[1] = STATIC_CAST(unsigned char, psDBF->nUpdateYearSince1900);
    abyHeader[2] = STATIC_CAST(unsigned char, psDBF->nUpdateMonth);
    abyHeader[3] = STATIC_CAST(unsigned char, psDBF->nUpdateDay);

    /* record count preset at zero */

    abyHeader[8] = STATIC_CAST(unsigned char, psDBF->nHeaderLength % 256);
    abyHeader[9] = STATIC_CAST(unsigned char, psDBF->nHeaderLength / 256);

    abyHeader[10] = STATIC_CAST(unsigned char, psDBF->nRecordLength % 256);
    abyHeader[11] = STATIC_CAST(unsigned char, psDBF->nRecordLength / 256);

    abyHeader[29] = STATIC_CAST(unsigned char, psDBF->iLanguageDriver);

    /* -------------------------------------------------------------------- */
    /*      Write the initial 32 byte file header, and all the field        */
    /*      descriptions.                                                   */
    /* -------------------------------------------------------------------- */
    psDBF->sHooks.FSeek(psDBF->fp, 0, 0);
    psDBF->sHooks.FWrite(abyHeader, XBASE_FILEHDR_SZ, 1, psDBF->fp);
    psDBF->sHooks.FWrite(psDBF->pszHeader, XBASE_FLDHDR_SZ, psDBF->nFields,
                         psDBF->fp);

    /* -------------------------------------------------------------------- */
    /*      Write out the newline character if there is room for it.        */
    /* -------------------------------------------------------------------- */
    if (psDBF->nHeaderLength >
        XBASE_FLDHDR_SZ * psDBF->nFields + XBASE_FLDHDR_SZ)
    {
        char cNewline = HEADER_RECORD_TERMINATOR;
        psDBF->sHooks.FWrite(&cNewline, 1, 1, psDBF->fp);
    }

    /* -------------------------------------------------------------------- */
    /*      If the file is new, add a EOF character.                        */
    /* -------------------------------------------------------------------- */
    if (psDBF->nRecords == 0 && psDBF->bWriteEndOfFileChar)
    {
        char ch = END_OF_FILE_CHARACTER;

        psDBF->sHooks.FWrite(&ch, 1, 1, psDBF->fp);
    }
}

/************************************************************************/
/*                           DBFFlushRecord()                           */
/*                                                                      */
/*      Write out the current record if there is one.                   */
/************************************************************************/

static bool DBFFlushRecord(DBFHandle psDBF)
{
    if (psDBF->bCurrentRecordModified && psDBF->nCurrentRecord > -1)
    {
        psDBF->bCurrentRecordModified = FALSE;

        const SAOffset nRecordOffset =
            psDBF->nRecordLength *
                STATIC_CAST(SAOffset, psDBF->nCurrentRecord) +
            psDBF->nHeaderLength;

        /* -------------------------------------------------------------------- */
        /*      Guard FSeek with check for whether we're already at position;   */
        /*      no-op FSeeks defeat network filesystems' write buffering.       */
        /* -------------------------------------------------------------------- */
        if (psDBF->bRequireNextWriteSeek ||
            psDBF->sHooks.FTell(psDBF->fp) != nRecordOffset)
        {
            if (psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0) != 0)
            {
                char szMessage[128];
                snprintf(
                    szMessage, sizeof(szMessage),
                    "Failure seeking to position before writing DBF record %d.",
                    psDBF->nCurrentRecord);
                psDBF->sHooks.Error(szMessage);
                return false;
            }
        }

        if (psDBF->sHooks.FWrite(psDBF->pszCurrentRecord, psDBF->nRecordLength,
                                 1, psDBF->fp) != 1)
        {
            char szMessage[128];
            snprintf(szMessage, sizeof(szMessage),
                     "Failure writing DBF record %d.", psDBF->nCurrentRecord);
            psDBF->sHooks.Error(szMessage);
            return false;
        }

        /* -------------------------------------------------------------------- */
        /*      If next op is also a write, allow possible skipping of FSeek.   */
        /* -------------------------------------------------------------------- */
        psDBF->bRequireNextWriteSeek = FALSE;

        if (psDBF->nCurrentRecord == psDBF->nRecords - 1)
        {
            if (psDBF->bWriteEndOfFileChar)
            {
                char ch = END_OF_FILE_CHARACTER;
                psDBF->sHooks.FWrite(&ch, 1, 1, psDBF->fp);
            }
        }
    }

    return true;
}

/************************************************************************/
/*                           DBFLoadRecord()                            */
/************************************************************************/

static bool DBFLoadRecord(DBFHandle psDBF, int iRecord)
{
    if (psDBF->nCurrentRecord != iRecord)
    {
        if (!DBFFlushRecord(psDBF))
            return false;

        const SAOffset nRecordOffset =
            psDBF->nRecordLength * STATIC_CAST(SAOffset, iRecord) +
            psDBF->nHeaderLength;

        if (psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, SEEK_SET) != 0)
        {
            char szMessage[128];
            snprintf(szMessage, sizeof(szMessage),
                     "fseek(%ld) failed on DBF file.",
                     STATIC_CAST(long, nRecordOffset));
            psDBF->sHooks.Error(szMessage);
            return false;
        }

        if (psDBF->sHooks.FRead(psDBF->pszCurrentRecord, psDBF->nRecordLength,
                                1, psDBF->fp) != 1)
        {
            char szMessage[128];
            snprintf(szMessage, sizeof(szMessage),
                     "fread(%d) failed on DBF file.", psDBF->nRecordLength);
            psDBF->sHooks.Error(szMessage);
            return false;
        }

        psDBF->nCurrentRecord = iRecord;
        /* -------------------------------------------------------------------- */
        /*      Require a seek for next write in case of mixed R/W operations.  */
        /* -------------------------------------------------------------------- */
        psDBF->bRequireNextWriteSeek = TRUE;
    }

    return true;
}

/************************************************************************/
/*                          DBFUpdateHeader()                           */
/************************************************************************/

void SHPAPI_CALL DBFUpdateHeader(DBFHandle psDBF)
{
    if (psDBF->bNoHeader)
        DBFWriteHeader(psDBF);

    if (!DBFFlushRecord(psDBF))
        return;

    psDBF->sHooks.FSeek(psDBF->fp, 0, 0);

    unsigned char abyFileHeader[XBASE_FILEHDR_SZ] = {0};
    psDBF->sHooks.FRead(abyFileHeader, 1, sizeof(abyFileHeader), psDBF->fp);

    abyFileHeader[1] = STATIC_CAST(unsigned char, psDBF->nUpdateYearSince1900);
    abyFileHeader[2] = STATIC_CAST(unsigned char, psDBF->nUpdateMonth);
    abyFileHeader[3] = STATIC_CAST(unsigned char, psDBF->nUpdateDay);
    abyFileHeader[4] = STATIC_CAST(unsigned char, psDBF->nRecords & 0xFF);
    abyFileHeader[5] =
        STATIC_CAST(unsigned char, (psDBF->nRecords >> 8) & 0xFF);
    abyFileHeader[6] =
        STATIC_CAST(unsigned char, (psDBF->nRecords >> 16) & 0xFF);
    abyFileHeader[7] =
        STATIC_CAST(unsigned char, (psDBF->nRecords >> 24) & 0xFF);

    psDBF->sHooks.FSeek(psDBF->fp, 0, 0);
    psDBF->sHooks.FWrite(abyFileHeader, sizeof(abyFileHeader), 1, psDBF->fp);

    psDBF->sHooks.FFlush(psDBF->fp);
}

/************************************************************************/
/*                       DBFSetLastModifiedDate()                       */
/************************************************************************/

void SHPAPI_CALL DBFSetLastModifiedDate(DBFHandle psDBF, int nYYSince1900,
                                        int nMM, int nDD)
{
    psDBF->nUpdateYearSince1900 = nYYSince1900;
    psDBF->nUpdateMonth = nMM;
    psDBF->nUpdateDay = nDD;
}

/************************************************************************/
/*                              DBFOpen()                               */
/*                                                                      */
/*      Open a .dbf file.                                               */
/************************************************************************/

DBFHandle SHPAPI_CALL DBFOpen(const char *pszFilename, const char *pszAccess)
{
    SAHooks sHooks;

    SASetupDefaultHooks(&sHooks);

    return DBFOpenLL(pszFilename, pszAccess, &sHooks);
}

/************************************************************************/
/*                     DBFGetLenWithoutExtension()                      */
/************************************************************************/

static int DBFGetLenWithoutExtension(const char *pszBasename)
{
    const int nLen = STATIC_CAST(int, strlen(pszBasename));
    for (int i = nLen - 1;
         i > 0 && pszBasename[i] != '/' && pszBasename[i] != '\\'; i--)
    {
        if (pszBasename[i] == '.')
        {
            return i;
        }
    }
    return nLen;
}

/************************************************************************/
/*                              DBFOpen()                               */
/*                                                                      */
/*      Open a .dbf file.                                               */
/************************************************************************/

DBFHandle SHPAPI_CALL DBFOpenLL(const char *pszFilename, const char *pszAccess,
                                const SAHooks *psHooks)
{
    /* -------------------------------------------------------------------- */
    /*      We only allow the access strings "rb" and "r+".                  */
    /* -------------------------------------------------------------------- */
    if (strcmp(pszAccess, "r") != 0 && strcmp(pszAccess, "r+") != 0 &&
        strcmp(pszAccess, "rb") != 0 && strcmp(pszAccess, "rb+") != 0 &&
        strcmp(pszAccess, "r+b") != 0)
        return SHPLIB_NULLPTR;

    if (strcmp(pszAccess, "r") == 0)
        pszAccess = "rb";

    if (strcmp(pszAccess, "r+") == 0)
        pszAccess = "rb+";

    /* -------------------------------------------------------------------- */
    /*      Compute the base (layer) name.  If there is any extension       */
    /*      on the passed in filename we will strip it off.                 */
    /* -------------------------------------------------------------------- */
    const int nLenWithoutExtension = DBFGetLenWithoutExtension(pszFilename);
    char *pszFullname = STATIC_CAST(char *, malloc(nLenWithoutExtension + 5));
    if (!pszFullname)
    {
        return SHPLIB_NULLPTR;
    }
    memcpy(pszFullname, pszFilename, nLenWithoutExtension);
    memcpy(pszFullname + nLenWithoutExtension, ".dbf", 5);

    DBFHandle psDBF = STATIC_CAST(DBFHandle, calloc(1, sizeof(DBFInfo)));
    if (!psDBF)
    {
        free(pszFullname);
        return SHPLIB_NULLPTR;
    }
    psDBF->fp = psHooks->FOpen(pszFullname, pszAccess, psHooks->pvUserData);
    memcpy(&(psDBF->sHooks), psHooks, sizeof(SAHooks));

    if (psDBF->fp == SHPLIB_NULLPTR)
    {
        memcpy(pszFullname + nLenWithoutExtension, ".DBF", 5);
        psDBF->fp =
            psDBF->sHooks.FOpen(pszFullname, pszAccess, psHooks->pvUserData);
    }

    memcpy(pszFullname + nLenWithoutExtension, ".cpg", 5);
    SAFile pfCPG = psHooks->FOpen(pszFullname, "r", psHooks->pvUserData);
    if (pfCPG == SHPLIB_NULLPTR)
    {
        memcpy(pszFullname + nLenWithoutExtension, ".CPG", 5);
        pfCPG = psHooks->FOpen(pszFullname, "r", psHooks->pvUserData);
    }

    free(pszFullname);

    if (psDBF->fp == SHPLIB_NULLPTR)
    {
        free(psDBF);
        if (pfCPG)
            psHooks->FClose(pfCPG);
        return SHPLIB_NULLPTR;
    }

    psDBF->bNoHeader = FALSE;
    psDBF->nCurrentRecord = -1;
    psDBF->bCurrentRecordModified = FALSE;

    /* -------------------------------------------------------------------- */
    /*  Read Table Header info                                              */
    /* -------------------------------------------------------------------- */
    const int nBufSize = 500;
    unsigned char *pabyBuf = STATIC_CAST(unsigned char *, malloc(nBufSize));
    if (!pabyBuf)
    {
        psDBF->sHooks.FClose(psDBF->fp);
        if (pfCPG)
            psHooks->FClose(pfCPG);
        free(psDBF);
        return SHPLIB_NULLPTR;
    }
    if (psDBF->sHooks.FRead(pabyBuf, XBASE_FILEHDR_SZ, 1, psDBF->fp) != 1)
    {
        psDBF->sHooks.FClose(psDBF->fp);
        if (pfCPG)
            psDBF->sHooks.FClose(pfCPG);
        free(pabyBuf);
        free(psDBF);
        return SHPLIB_NULLPTR;
    }

    DBFSetLastModifiedDate(psDBF, pabyBuf[1], pabyBuf[2], pabyBuf[3]);

    psDBF->nRecords = pabyBuf[4] | (pabyBuf[5] << 8) | (pabyBuf[6] << 16) |
                      ((pabyBuf[7] & 0x7f) << 24);

    const int nHeadLen = pabyBuf[8] | (pabyBuf[9] << 8);
    psDBF->nHeaderLength = nHeadLen;
    psDBF->nRecordLength = pabyBuf[10] | (pabyBuf[11] << 8);
    psDBF->iLanguageDriver = pabyBuf[29];

    if (psDBF->nRecordLength == 0 || nHeadLen < XBASE_FILEHDR_SZ)
    {
        psDBF->sHooks.FClose(psDBF->fp);
        if (pfCPG)
            psDBF->sHooks.FClose(pfCPG);
        free(pabyBuf);
        free(psDBF);
        return SHPLIB_NULLPTR;
    }

    const int nFields = (nHeadLen - XBASE_FILEHDR_SZ) / XBASE_FLDHDR_SZ;
    psDBF->nFields = nFields;

    assert(psDBF->nRecordLength < 65536);
    psDBF->pszCurrentRecord = STATIC_CAST(char *, malloc(psDBF->nRecordLength));
    if (!psDBF->pszCurrentRecord)
    {
        psDBF->sHooks.FClose(psDBF->fp);
        if (pfCPG)
            psDBF->sHooks.FClose(pfCPG);
        free(pabyBuf);
        free(psDBF);
        return SHPLIB_NULLPTR;
    }

    /* -------------------------------------------------------------------- */
    /*  Figure out the code page from the LDID and CPG                      */
    /* -------------------------------------------------------------------- */
    psDBF->pszCodePage = SHPLIB_NULLPTR;
    if (pfCPG)
    {
        memset(pabyBuf, 0, nBufSize);
        psDBF->sHooks.FRead(pabyBuf, 1, nBufSize - 1, pfCPG);
        const size_t n = strcspn(REINTERPRET_CAST(char *, pabyBuf), "\n\r");
        if (n > 0)
        {
            pabyBuf[n] = '\0';
            psDBF->pszCodePage = STATIC_CAST(char *, malloc(n + 1));
            if (psDBF->pszCodePage)
                memcpy(psDBF->pszCodePage, pabyBuf, n + 1);
        }
        psDBF->sHooks.FClose(pfCPG);
    }
    if (psDBF->pszCodePage == SHPLIB_NULLPTR && pabyBuf[29] != 0)
    {
        snprintf(REINTERPRET_CAST(char *, pabyBuf), nBufSize, "LDID/%d",
                 psDBF->iLanguageDriver);
        psDBF->pszCodePage = STATIC_CAST(
            char *, malloc(strlen(REINTERPRET_CAST(char *, pabyBuf)) + 1));
        if (psDBF->pszCodePage)
            strcpy(psDBF->pszCodePage, REINTERPRET_CAST(char *, pabyBuf));
    }

    /* -------------------------------------------------------------------- */
    /*  Read in Field Definitions                                           */
    /* -------------------------------------------------------------------- */

    // To please Coverity Scan
    assert(nHeadLen < 65536);
    unsigned char *pabyBufNew =
        STATIC_CAST(unsigned char *, realloc(pabyBuf, nHeadLen));
    if (!pabyBufNew)
    {
        psDBF->sHooks.FClose(psDBF->fp);
        free(pabyBuf);
        free(psDBF->pszCurrentRecord);
        free(psDBF->pszCodePage);
        free(psDBF);
        return SHPLIB_NULLPTR;
    }
    pabyBuf = pabyBufNew;
    psDBF->pszHeader = REINTERPRET_CAST(char *, pabyBuf);

    psDBF->sHooks.FSeek(psDBF->fp, XBASE_FILEHDR_SZ, 0);
    if (psDBF->sHooks.FRead(pabyBuf, nHeadLen - XBASE_FILEHDR_SZ, 1,
                            psDBF->fp) != 1)
    {
        psDBF->sHooks.FClose(psDBF->fp);
        free(pabyBuf);
        free(psDBF->pszCurrentRecord);
        free(psDBF->pszCodePage);
        free(psDBF);
        return SHPLIB_NULLPTR;
    }

    psDBF->panFieldOffset = STATIC_CAST(int *, malloc(sizeof(int) * nFields));
    psDBF->panFieldSize = STATIC_CAST(int *, malloc(sizeof(int) * nFields));
    psDBF->panFieldDecimals = STATIC_CAST(int *, malloc(sizeof(int) * nFields));
    psDBF->pachFieldType = STATIC_CAST(char *, malloc(sizeof(char) * nFields));
    if (!psDBF->panFieldOffset || !psDBF->panFieldSize ||
        !psDBF->panFieldDecimals || !psDBF->pachFieldType)
    {
        DBFClose(psDBF);
        return SHPLIB_NULLPTR;
    }

    for (int iField = 0; iField < nFields; iField++)
    {
        const unsigned char *pabyFInfo = pabyBuf + iField * XBASE_FLDHDR_SZ;
        if (pabyFInfo[0] == HEADER_RECORD_TERMINATOR)
        {
            psDBF->nFields = iField;
            break;
        }

        if (pabyFInfo[11] == 'N' || pabyFInfo[11] == 'F')
        {
            psDBF->panFieldSize[iField] = pabyFInfo[16];
            psDBF->panFieldDecimals[iField] = pabyFInfo[17];
        }
        else
        {
            psDBF->panFieldSize[iField] = pabyFInfo[16];
            psDBF->panFieldDecimals[iField] = 0;

            /*
            ** The following seemed to be used sometimes to handle files with
            long
            ** string fields, but in other cases (such as bug 1202) the decimals
            field
            ** just seems to indicate some sort of preferred formatting, not
            very
            ** wide fields.  So I have disabled this code.  FrankW.
                    psDBF->panFieldSize[iField] = pabyFInfo[16] +
            pabyFInfo[17]*256; psDBF->panFieldDecimals[iField] = 0;
            */
        }

        psDBF->pachFieldType[iField] = STATIC_CAST(char, pabyFInfo[11]);
        if (iField == 0)
            psDBF->panFieldOffset[iField] = 1;
        else
            psDBF->panFieldOffset[iField] = psDBF->panFieldOffset[iField - 1] +
                                            psDBF->panFieldSize[iField - 1];
    }

    /* Check that the total width of fields does not exceed the record width */
    if (psDBF->nFields > 0 && psDBF->panFieldOffset[psDBF->nFields - 1] +
                                      psDBF->panFieldSize[psDBF->nFields - 1] >
                                  psDBF->nRecordLength)
    {
        DBFClose(psDBF);
        return SHPLIB_NULLPTR;
    }

    DBFSetWriteEndOfFileChar(psDBF, TRUE);

    psDBF->bRequireNextWriteSeek = TRUE;

    return (psDBF);
}

/************************************************************************/
/*                              DBFClose()                              */
/************************************************************************/

void SHPAPI_CALL DBFClose(DBFHandle psDBF)
{
    if (psDBF == SHPLIB_NULLPTR)
        return;

    /* -------------------------------------------------------------------- */
    /*      Write out header if not already written.                        */
    /* -------------------------------------------------------------------- */
    if (psDBF->bNoHeader)
        DBFWriteHeader(psDBF);

    CPL_IGNORE_RET_VAL_INT(DBFFlushRecord(psDBF));

    /* -------------------------------------------------------------------- */
    /*      Update last access date, and number of records if we have       */
    /*      write access.                                                   */
    /* -------------------------------------------------------------------- */
    if (psDBF->bUpdated)
        DBFUpdateHeader(psDBF);

    /* -------------------------------------------------------------------- */
    /*      Close, and free resources.                                      */
    /* -------------------------------------------------------------------- */
    psDBF->sHooks.FClose(psDBF->fp);

    if (psDBF->panFieldOffset != SHPLIB_NULLPTR)
    {
        free(psDBF->panFieldOffset);
        free(psDBF->panFieldSize);
        free(psDBF->panFieldDecimals);
        free(psDBF->pachFieldType);
    }

    if (psDBF->pszWorkField != SHPLIB_NULLPTR)
        free(psDBF->pszWorkField);

    free(psDBF->pszHeader);
    free(psDBF->pszCurrentRecord);
    free(psDBF->pszCodePage);

    free(psDBF);
}

/************************************************************************/
/*                             DBFCreate()                              */
/*                                                                      */
/* Create a new .dbf file with default code page LDID/87 (0x57)         */
/************************************************************************/

DBFHandle SHPAPI_CALL DBFCreate(const char *pszFilename)
{
    return DBFCreateEx(pszFilename, "LDID/87");  // 0x57
}

/************************************************************************/
/*                            DBFCreateEx()                             */
/*                                                                      */
/*      Create a new .dbf file.                                         */
/************************************************************************/

DBFHandle SHPAPI_CALL DBFCreateEx(const char *pszFilename,
                                  const char *pszCodePage)
{
    SAHooks sHooks;

    SASetupDefaultHooks(&sHooks);

    return DBFCreateLL(pszFilename, pszCodePage, &sHooks);
}

/************************************************************************/
/*                             DBFCreate()                              */
/*                                                                      */
/*      Create a new .dbf file.                                         */
/************************************************************************/

DBFHandle SHPAPI_CALL DBFCreateLL(const char *pszFilename,
                                  const char *pszCodePage,
                                  const SAHooks *psHooks)
{
    /* -------------------------------------------------------------------- */
    /*      Compute the base (layer) name.  If there is any extension       */
    /*      on the passed in filename we will strip it off.                 */
    /* -------------------------------------------------------------------- */
    const int nLenWithoutExtension = DBFGetLenWithoutExtension(pszFilename);
    char *pszFullname = STATIC_CAST(char *, malloc(nLenWithoutExtension + 5));
    if (!pszFullname)
        return SHPLIB_NULLPTR;
    memcpy(pszFullname, pszFilename, nLenWithoutExtension);
    memcpy(pszFullname + nLenWithoutExtension, ".dbf", 5);

    /* -------------------------------------------------------------------- */
    /*      Create the file.                                                */
    /* -------------------------------------------------------------------- */
    SAFile fp = psHooks->FOpen(pszFullname, "wb+", psHooks->pvUserData);
    if (fp == SHPLIB_NULLPTR)
    {
        const size_t nMessageLen = strlen(pszFullname) + 256;
        char *pszMessage = STATIC_CAST(char *, malloc(nMessageLen));
        if (pszMessage)
        {
            snprintf(pszMessage, nMessageLen, "Failed to create file %s: %s",
                     pszFullname, strerror(errno));
            psHooks->Error(pszMessage);
            free(pszMessage);
        }

        free(pszFullname);
        return SHPLIB_NULLPTR;
    }

    memcpy(pszFullname + nLenWithoutExtension, ".cpg", 5);
    int ldid = -1;
    if (pszCodePage != SHPLIB_NULLPTR)
    {
        if (strncmp(pszCodePage, "LDID/", 5) == 0)
        {
            ldid = atoi(pszCodePage + 5);
            if (ldid > 255)
                ldid = -1;  // don't use 0 to indicate out of range as LDID/0 is
                            // a valid one
        }
        if (ldid < 0)
        {
            SAFile fpCPG =
                psHooks->FOpen(pszFullname, "w", psHooks->pvUserData);
            psHooks->FWrite(
                CONST_CAST(void *, STATIC_CAST(const void *, pszCodePage)),
                strlen(pszCodePage), 1, fpCPG);
            psHooks->FClose(fpCPG);
        }
    }
    if (pszCodePage == SHPLIB_NULLPTR || ldid >= 0)
    {
        psHooks->Remove(pszFullname, psHooks->pvUserData);
    }

    free(pszFullname);

    /* -------------------------------------------------------------------- */
    /*      Create the info structure.                                      */
    /* -------------------------------------------------------------------- */
    DBFHandle psDBF = STATIC_CAST(DBFHandle, calloc(1, sizeof(DBFInfo)));
    if (!psDBF)
    {
        return SHPLIB_NULLPTR;
    }

    memcpy(&(psDBF->sHooks), psHooks, sizeof(SAHooks));
    psDBF->fp = fp;
    psDBF->nRecords = 0;
    psDBF->nFields = 0;
    psDBF->nRecordLength = 1;
    psDBF->nHeaderLength =
        XBASE_FILEHDR_SZ + 1; /* + 1 for HEADER_RECORD_TERMINATOR */

    psDBF->panFieldOffset = SHPLIB_NULLPTR;
    psDBF->panFieldSize = SHPLIB_NULLPTR;
    psDBF->panFieldDecimals = SHPLIB_NULLPTR;
    psDBF->pachFieldType = SHPLIB_NULLPTR;
    psDBF->pszHeader = SHPLIB_NULLPTR;

    psDBF->nCurrentRecord = -1;
    psDBF->bCurrentRecordModified = FALSE;
    psDBF->pszCurrentRecord = SHPLIB_NULLPTR;

    psDBF->bNoHeader = TRUE;

    psDBF->iLanguageDriver = ldid > 0 ? ldid : 0;
    psDBF->pszCodePage = SHPLIB_NULLPTR;
    if (pszCodePage)
    {
        psDBF->pszCodePage =
            STATIC_CAST(char *, malloc(strlen(pszCodePage) + 1));
        if (psDBF->pszCodePage)
            strcpy(psDBF->pszCodePage, pszCodePage);
    }
    DBFSetLastModifiedDate(psDBF, 95, 7, 26); /* dummy date */

    DBFSetWriteEndOfFileChar(psDBF, TRUE);

    psDBF->bRequireNextWriteSeek = TRUE;

    return (psDBF);
}

/************************************************************************/
/*                            DBFAddField()                             */
/*                                                                      */
/*      Add a field to a newly created .dbf or to an existing one       */
/************************************************************************/

int SHPAPI_CALL DBFAddField(DBFHandle psDBF, const char *pszFieldName,
                            DBFFieldType eType, int nWidth, int nDecimals)
{
    char chNativeType;

    if (eType == FTLogical)
        chNativeType = 'L';
    else if (eType == FTDate)
        chNativeType = 'D';
    else if (eType == FTString)
        chNativeType = 'C';
    else
        chNativeType = 'N';

    return DBFAddNativeFieldType(psDBF, pszFieldName, chNativeType, nWidth,
                                 nDecimals);
}

/************************************************************************/
/*                        DBFGetNullCharacter()                         */
/************************************************************************/

static char DBFGetNullCharacter(char chType)
{
    switch (chType)
    {
        case 'N':
        case 'F':
            return '*';
        case 'D':
            return '0';
        case 'L':
            return '?';
        default:
            return ' ';
    }
}

/************************************************************************/
/*                            DBFAddField()                             */
/*                                                                      */
/*      Add a field to a newly created .dbf file before any records     */
/*      are written.                                                    */
/************************************************************************/

int SHPAPI_CALL DBFAddNativeFieldType(DBFHandle psDBF, const char *pszFieldName,
                                      char chType, int nWidth, int nDecimals)
{
    /* make sure that everything is written in .dbf */
    if (!DBFFlushRecord(psDBF))
        return -1;

    if (psDBF->nHeaderLength + XBASE_FLDHDR_SZ > 65535)
    {
        char szMessage[128];
        snprintf(szMessage, sizeof(szMessage),
                 "Cannot add field %s. Header length limit reached "
                 "(max 65535 bytes, 2046 fields).",
                 pszFieldName);
        psDBF->sHooks.Error(szMessage);
        return -1;
    }

    /* -------------------------------------------------------------------- */
    /*      Do some checking to ensure we can add records to this file.     */
    /* -------------------------------------------------------------------- */
    if (nWidth < 1)
        return -1;

    if (nWidth > XBASE_FLD_MAX_WIDTH)
        nWidth = XBASE_FLD_MAX_WIDTH;

    if (psDBF->nRecordLength + nWidth > 65535)
    {
        char szMessage[128];
        snprintf(szMessage, sizeof(szMessage),
                 "Cannot add field %s. Record length limit reached "
                 "(max 65535 bytes).",
                 pszFieldName);
        psDBF->sHooks.Error(szMessage);
        return -1;
    }

    const int nOldRecordLength = psDBF->nRecordLength;
    const int nOldHeaderLength = psDBF->nHeaderLength;

    /* -------------------------------------------------------------------- */
    /*      realloc all the arrays larger to hold the additional field      */
    /*      information.                                                    */
    /* -------------------------------------------------------------------- */

    int *panFieldOffsetNew =
        STATIC_CAST(int *, realloc(psDBF->panFieldOffset,
                                   sizeof(int) * (psDBF->nFields + 1)));

    int *panFieldSizeNew =
        STATIC_CAST(int *, realloc(psDBF->panFieldSize,
                                   sizeof(int) * (psDBF->nFields + 1)));

    int *panFieldDecimalsNew =
        STATIC_CAST(int *, realloc(psDBF->panFieldDecimals,
                                   sizeof(int) * (psDBF->nFields + 1)));

    char *pachFieldTypeNew =
        STATIC_CAST(char *, realloc(psDBF->pachFieldType,
                                    sizeof(char) * (psDBF->nFields + 1)));

    char *pszHeaderNew =
        STATIC_CAST(char *, realloc(psDBF->pszHeader,
                                    (psDBF->nFields + 1) * XBASE_FLDHDR_SZ));

    /* -------------------------------------------------------------------- */
    /*      Make the current record buffer appropriately larger.            */
    /* -------------------------------------------------------------------- */
    char *pszCurrentRecordNew =
        STATIC_CAST(char *, realloc(psDBF->pszCurrentRecord,
                                    psDBF->nRecordLength + nWidth));

    if (panFieldOffsetNew)
        psDBF->panFieldOffset = panFieldOffsetNew;
    if (panFieldSizeNew)
        psDBF->panFieldSize = panFieldSizeNew;
    if (panFieldDecimalsNew)
        psDBF->panFieldDecimals = panFieldDecimalsNew;
    if (pachFieldTypeNew)
        psDBF->pachFieldType = pachFieldTypeNew;
    if (pszHeaderNew)
        psDBF->pszHeader = pszHeaderNew;
    if (pszCurrentRecordNew)
        psDBF->pszCurrentRecord = pszCurrentRecordNew;

    if (!panFieldOffsetNew || !panFieldSizeNew || !panFieldDecimalsNew ||
        !pachFieldTypeNew || !pszHeaderNew || !pszCurrentRecordNew)
    {
        psDBF->sHooks.Error("Out of memory");
        return -1;
    }

    /* alloc record */
    char *pszRecord = SHPLIB_NULLPTR;
    if (!psDBF->bNoHeader)
    {
        pszRecord = STATIC_CAST(char *, malloc(psDBF->nRecordLength + nWidth));
        if (!pszRecord)
        {
            psDBF->sHooks.Error("Out of memory");
            return -1;
        }
    }

    psDBF->nFields++;

    /* -------------------------------------------------------------------- */
    /*      Assign the new field information fields.                        */
    /* -------------------------------------------------------------------- */
    psDBF->panFieldOffset[psDBF->nFields - 1] = psDBF->nRecordLength;
    psDBF->nRecordLength += nWidth;
    psDBF->panFieldSize[psDBF->nFields - 1] = nWidth;
    psDBF->panFieldDecimals[psDBF->nFields - 1] = nDecimals;
    psDBF->pachFieldType[psDBF->nFields - 1] = chType;

    /* -------------------------------------------------------------------- */
    /*      Extend the required header information.                         */
    /* -------------------------------------------------------------------- */
    psDBF->nHeaderLength += XBASE_FLDHDR_SZ;
    psDBF->bUpdated = FALSE;

    char *pszFInfo = psDBF->pszHeader + XBASE_FLDHDR_SZ * (psDBF->nFields - 1);

    for (int i = 0; i < XBASE_FLDHDR_SZ; i++)
        pszFInfo[i] = '\0';

    strncpy(pszFInfo, pszFieldName, XBASE_FLDNAME_LEN_WRITE);

    pszFInfo[11] = psDBF->pachFieldType[psDBF->nFields - 1];

    if (chType == 'C')
    {
        pszFInfo[16] = STATIC_CAST(unsigned char, nWidth % 256);
        pszFInfo[17] = STATIC_CAST(unsigned char, nWidth / 256);
    }
    else
    {
        pszFInfo[16] = STATIC_CAST(unsigned char, nWidth);
        pszFInfo[17] = STATIC_CAST(unsigned char, nDecimals);
    }

    /* we're done if dealing with new .dbf */
    if (psDBF->bNoHeader)
        return (psDBF->nFields - 1);

    /* -------------------------------------------------------------------- */
    /*      For existing .dbf file, shift records                           */
    /* -------------------------------------------------------------------- */

    const char chFieldFill = DBFGetNullCharacter(chType);

    SAOffset nRecordOffset;
    for (int i = psDBF->nRecords - 1; i >= 0; --i)
    {
        nRecordOffset =
            nOldRecordLength * STATIC_CAST(SAOffset, i) + nOldHeaderLength;

        /* load record */
        psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
        if (psDBF->sHooks.FRead(pszRecord, nOldRecordLength, 1, psDBF->fp) != 1)
        {
            free(pszRecord);
            return -1;
        }

        /* set new field's value to NULL */
        memset(pszRecord + nOldRecordLength, chFieldFill, nWidth);

        nRecordOffset = psDBF->nRecordLength * STATIC_CAST(SAOffset, i) +
                        psDBF->nHeaderLength;

        /* move record to the new place*/
        psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
        psDBF->sHooks.FWrite(pszRecord, psDBF->nRecordLength, 1, psDBF->fp);
    }

    if (psDBF->bWriteEndOfFileChar)
    {
        char ch = END_OF_FILE_CHARACTER;

        nRecordOffset =
            psDBF->nRecordLength * STATIC_CAST(SAOffset, psDBF->nRecords) +
            psDBF->nHeaderLength;

        psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
        psDBF->sHooks.FWrite(&ch, 1, 1, psDBF->fp);
    }

    /* free record */
    free(pszRecord);

    /* force update of header with new header, record length and new field */
    psDBF->bNoHeader = TRUE;
    DBFUpdateHeader(psDBF);

    psDBF->nCurrentRecord = -1;
    psDBF->bCurrentRecordModified = FALSE;
    psDBF->bUpdated = TRUE;

    return (psDBF->nFields - 1);
}

/************************************************************************/
/*                          DBFReadAttribute()                          */
/*                                                                      */
/*      Read one of the attribute fields of a record.                   */
/************************************************************************/

static void *DBFReadAttribute(DBFHandle psDBF, int hEntity, int iField,
                              char chReqType)
{
    /* -------------------------------------------------------------------- */
    /*      Verify selection.                                               */
    /* -------------------------------------------------------------------- */
    if (hEntity < 0 || hEntity >= psDBF->nRecords)
        return SHPLIB_NULLPTR;

    if (iField < 0 || iField >= psDBF->nFields)
        return SHPLIB_NULLPTR;

    /* -------------------------------------------------------------------- */
    /*     Have we read the record?                                         */
    /* -------------------------------------------------------------------- */
    if (!DBFLoadRecord(psDBF, hEntity))
        return SHPLIB_NULLPTR;

    const unsigned char *pabyRec =
        REINTERPRET_CAST(const unsigned char *, psDBF->pszCurrentRecord);

    /* -------------------------------------------------------------------- */
    /*      Ensure we have room to extract the target field.                */
    /* -------------------------------------------------------------------- */
    if (psDBF->panFieldSize[iField] >= psDBF->nWorkFieldLength)
    {
        psDBF->nWorkFieldLength = psDBF->panFieldSize[iField] + 100;
        if (psDBF->pszWorkField == SHPLIB_NULLPTR)
            psDBF->pszWorkField =
                STATIC_CAST(char *, malloc(psDBF->nWorkFieldLength));
        else
            psDBF->pszWorkField = STATIC_CAST(
                char *, realloc(psDBF->pszWorkField, psDBF->nWorkFieldLength));
    }

    /* -------------------------------------------------------------------- */
    /*      Extract the requested field.                                    */
    /* -------------------------------------------------------------------- */
    memcpy(psDBF->pszWorkField,
           REINTERPRET_CAST(const char *, pabyRec) +
               psDBF->panFieldOffset[iField],
           psDBF->panFieldSize[iField]);
    psDBF->pszWorkField[psDBF->panFieldSize[iField]] = '\0';

    void *pReturnField = psDBF->pszWorkField;

    /* -------------------------------------------------------------------- */
    /*      Decode the field.                                               */
    /* -------------------------------------------------------------------- */
    if (chReqType == 'I')
    {
        psDBF->fieldValue.nIntField = atoi(psDBF->pszWorkField);

        pReturnField = &(psDBF->fieldValue.nIntField);
    }
    else if (chReqType == 'N')
    {
        psDBF->fieldValue.dfDoubleField =
            psDBF->sHooks.Atof(psDBF->pszWorkField);

        pReturnField = &(psDBF->fieldValue.dfDoubleField);
    }

/* -------------------------------------------------------------------- */
/*      Should we trim white space off the string attribute value?      */
/* -------------------------------------------------------------------- */
#ifdef TRIM_DBF_WHITESPACE
    else
    {
        char *pchSrc = psDBF->pszWorkField;
        char *pchDst = pchSrc;

        while (*pchSrc == ' ')
            pchSrc++;

        while (*pchSrc != '\0')
            *(pchDst++) = *(pchSrc++);
        *pchDst = '\0';

        while (pchDst != psDBF->pszWorkField && *(--pchDst) == ' ')
            *pchDst = '\0';
    }
#endif

    return pReturnField;
}

/************************************************************************/
/*                        DBFReadIntAttribute()                         */
/*                                                                      */
/*      Read an integer attribute.                                      */
/************************************************************************/

int SHPAPI_CALL DBFReadIntegerAttribute(DBFHandle psDBF, int iRecord,
                                        int iField)
{
    int *pnValue =
        STATIC_CAST(int *, DBFReadAttribute(psDBF, iRecord, iField, 'I'));

    if (pnValue == SHPLIB_NULLPTR)
        return 0;
    else
        return *pnValue;
}

/************************************************************************/
/*                        DBFReadDoubleAttribute()                      */
/*                                                                      */
/*      Read a double attribute.                                        */
/************************************************************************/

double SHPAPI_CALL DBFReadDoubleAttribute(DBFHandle psDBF, int iRecord,
                                          int iField)
{
    double *pdValue =
        STATIC_CAST(double *, DBFReadAttribute(psDBF, iRecord, iField, 'N'));

    if (pdValue == SHPLIB_NULLPTR)
        return 0.0;
    else
        return *pdValue;
}

/************************************************************************/
/*                        DBFReadStringAttribute()                      */
/*                                                                      */
/*      Read a string attribute.                                        */
/************************************************************************/

const char SHPAPI_CALL1(*)
    DBFReadStringAttribute(DBFHandle psDBF, int iRecord, int iField)
{
    return STATIC_CAST(const char *,
                       DBFReadAttribute(psDBF, iRecord, iField, 'C'));
}

/************************************************************************/
/*                        DBFReadLogicalAttribute()                     */
/*                                                                      */
/*      Read a logical attribute.                                       */
/************************************************************************/

const char SHPAPI_CALL1(*)
    DBFReadLogicalAttribute(DBFHandle psDBF, int iRecord, int iField)
{
    return STATIC_CAST(const char *,
                       DBFReadAttribute(psDBF, iRecord, iField, 'L'));
}

/************************************************************************/
/*                        DBFReadDateAttribute()                        */
/*                                                                      */
/*      Read a date attribute.                                          */
/************************************************************************/

SHPDate SHPAPI_CALL DBFReadDateAttribute(DBFHandle psDBF, int iRecord,
                                         int iField)
{
    const char *pdateValue = STATIC_CAST(
        const char *, DBFReadAttribute(psDBF, iRecord, iField, 'D'));

    SHPDate date;

    if (pdateValue == SHPLIB_NULLPTR)
    {
        date.year = 0;
        date.month = 0;
        date.day = 0;
    }
    else if (3 != sscanf(pdateValue, "%4d%2d%2d", &date.year, &date.month,
                         &date.day))
    {
        date.year = 0;
        date.month = 0;
        date.day = 0;
    }

    return date;
}

/************************************************************************/
/*                         DBFIsValueNULL()                             */
/*                                                                      */
/*      Return TRUE if the passed string is NULL.                       */
/************************************************************************/

static bool DBFIsValueNULL(char chType, const char *pszValue, int size)
{
    if (pszValue == SHPLIB_NULLPTR)
        return true;

    switch (chType)
    {
        case 'N':
        case 'F':
            /*
            ** We accept all asterisks or all blanks as NULL
            ** though according to the spec I think it should be all
            ** asterisks.
            */
            if (pszValue[0] == '*')
                return true;

            for (int i = 0; pszValue[i] != '\0'; i++)
            {
                if (pszValue[i] != ' ')
                    return false;
            }
            return true;

        case 'D':
        {
            const char DIGIT_ZERO = '0';
            /* NULL date fields have value "00000000" or "0"*size */
            /* Some DBF files have fields filled with spaces */
            /* (trimmed by DBFReadStringAttribute) to indicate null */
            /* values for dates (#4265). */
            /* And others have '       0': https://lists.osgeo.org/pipermail/gdal-dev/2023-November/058010.html */
            /* And others just empty string: https://github.com/OSGeo/gdal/issues/10405 */
            if (pszValue[0] == 0 || strncmp(pszValue, "00000000", 8) == 0 ||
                strcmp(pszValue, " ") == 0 || strcmp(pszValue, "0") == 0)
                return true;
            for (int i = 0; i < size; i++)
                if (pszValue[i] != DIGIT_ZERO)
                    return false;
            return true;
        }

        case 'L':
            /* NULL boolean fields have value "?" */
            return pszValue[0] == '?';

        default:
            /* empty string fields are considered NULL */
            return strlen(pszValue) == 0;
    }
}

/************************************************************************/
/*                         DBFIsAttributeNULL()                         */
/*                                                                      */
/*      Return TRUE if value for field is NULL.                         */
/*                                                                      */
/*      Contributed by Jim Matthews.                                    */
/************************************************************************/

int SHPAPI_CALL DBFIsAttributeNULL(const DBFHandle psDBF, int iRecord,
                                   int iField)
{
    const char *pszValue = DBFReadStringAttribute(psDBF, iRecord, iField);

    if (pszValue == SHPLIB_NULLPTR)
        return TRUE;

    return DBFIsValueNULL(psDBF->pachFieldType[iField], pszValue,
                          psDBF->panFieldSize[iField]);
}

/************************************************************************/
/*                          DBFGetFieldCount()                          */
/*                                                                      */
/*      Return the number of fields in this table.                      */
/************************************************************************/

int SHPAPI_CALL DBFGetFieldCount(const DBFHandle psDBF)
{
    return (psDBF->nFields);
}

/************************************************************************/
/*                         DBFGetRecordCount()                          */
/*                                                                      */
/*      Return the number of records in this table.                     */
/************************************************************************/

int SHPAPI_CALL DBFGetRecordCount(const DBFHandle psDBF)
{
    return (psDBF->nRecords);
}

/************************************************************************/
/*                          DBFGetFieldInfo()                           */
/*                                                                      */
/*      Return any requested information about the field.               */
/*      pszFieldName must be at least XBASE_FLDNAME_LEN_READ+1 (=12)    */
/*      bytes long.                                                     */
/************************************************************************/

DBFFieldType SHPAPI_CALL DBFGetFieldInfo(const DBFHandle psDBF, int iField,
                                         char *pszFieldName, int *pnWidth,
                                         int *pnDecimals)
{
    if (iField < 0 || iField >= psDBF->nFields)
        return (FTInvalid);

    if (pnWidth != SHPLIB_NULLPTR)
        *pnWidth = psDBF->panFieldSize[iField];

    if (pnDecimals != SHPLIB_NULLPTR)
        *pnDecimals = psDBF->panFieldDecimals[iField];

    if (pszFieldName != SHPLIB_NULLPTR)
    {
        strncpy(pszFieldName,
                STATIC_CAST(char *, psDBF->pszHeader) +
                    iField * XBASE_FLDHDR_SZ,
                XBASE_FLDNAME_LEN_READ);
        pszFieldName[XBASE_FLDNAME_LEN_READ] = '\0';
        for (int i = XBASE_FLDNAME_LEN_READ - 1;
             i > 0 && pszFieldName[i] == ' '; i--)
            pszFieldName[i] = '\0';
    }

    if (psDBF->pachFieldType[iField] == 'L')
        return (FTLogical);

    else if (psDBF->pachFieldType[iField] == 'D')
        return (FTDate);

    else if (psDBF->pachFieldType[iField] == 'N' ||
             psDBF->pachFieldType[iField] == 'F')
    {
        if (psDBF->panFieldDecimals[iField] > 0 ||
            psDBF->panFieldSize[iField] >= 10)
            return (FTDouble);
        else
            return (FTInteger);
    }
    else
    {
        return (FTString);
    }
}

/************************************************************************/
/*                         DBFWriteAttribute()                          */
/*                                                                      */
/*      Write an attribute record to the file.                          */
/************************************************************************/

static bool DBFWriteAttribute(DBFHandle psDBF, int hEntity, int iField,
                              void *pValue)
{
    /* -------------------------------------------------------------------- */
    /*      Is this a valid record?                                         */
    /* -------------------------------------------------------------------- */
    if (hEntity < 0 || hEntity > psDBF->nRecords)
        return false;

    if (psDBF->bNoHeader)
        DBFWriteHeader(psDBF);

    /* -------------------------------------------------------------------- */
    /*      Is this a brand new record?                                     */
    /* -------------------------------------------------------------------- */
    if (hEntity == psDBF->nRecords)
    {
        if (!DBFFlushRecord(psDBF))
            return false;

        psDBF->nRecords++;
        for (int i = 0; i < psDBF->nRecordLength; i++)
            psDBF->pszCurrentRecord[i] = ' ';

        psDBF->nCurrentRecord = hEntity;
    }

    /* -------------------------------------------------------------------- */
    /*      Is this an existing record, but different than the last one     */
    /*      we accessed?                                                    */
    /* -------------------------------------------------------------------- */
    if (!DBFLoadRecord(psDBF, hEntity))
        return false;

    unsigned char *pabyRec =
        REINTERPRET_CAST(unsigned char *, psDBF->pszCurrentRecord);

    psDBF->bCurrentRecordModified = TRUE;
    psDBF->bUpdated = TRUE;

    /* -------------------------------------------------------------------- */
    /*      Translate NULL value to valid DBF file representation.          */
    /*                                                                      */
    /*      Contributed by Jim Matthews.                                    */
    /* -------------------------------------------------------------------- */
    if (pValue == SHPLIB_NULLPTR)
    {
        memset(pabyRec + psDBF->panFieldOffset[iField],
               DBFGetNullCharacter(psDBF->pachFieldType[iField]),
               psDBF->panFieldSize[iField]);
        return true;
    }

    /* -------------------------------------------------------------------- */
    /*      Assign all the record fields.                                   */
    /* -------------------------------------------------------------------- */
    bool nRetResult = true;

    switch (psDBF->pachFieldType[iField])
    {
        case 'D':
        case 'N':
        case 'F':
        {
            int nWidth = psDBF->panFieldSize[iField];

            char szSField[XBASE_FLD_MAX_WIDTH + 1];
            if (STATIC_CAST(int, sizeof(szSField)) - 2 < nWidth)
                nWidth = sizeof(szSField) - 2;

            char szFormat[20];
            snprintf(szFormat, sizeof(szFormat), "%%%d.%df", nWidth,
                     psDBF->panFieldDecimals[iField]);
            const double value = *STATIC_CAST(double *, pValue);
            CPLsnprintf(szSField, sizeof(szSField), szFormat, value);
            szSField[sizeof(szSField) - 1] = '\0';
            if (STATIC_CAST(int, strlen(szSField)) >
                psDBF->panFieldSize[iField])
            {
                szSField[psDBF->panFieldSize[iField]] = '\0';
                nRetResult = psDBF->sHooks.Atof(szSField) == value;
            }
            memcpy(REINTERPRET_CAST(char *,
                                    pabyRec + psDBF->panFieldOffset[iField]),
                   szSField, strlen(szSField));
            break;
        }

        case 'L':
            if (psDBF->panFieldSize[iField] >= 1 &&
                (*STATIC_CAST(char *, pValue) == 'F' ||
                 *STATIC_CAST(char *, pValue) == 'T'))
            {
                *(pabyRec + psDBF->panFieldOffset[iField]) =
                    *STATIC_CAST(char *, pValue);
            }
            else
            {
                nRetResult = false;
            }
            break;

        default:
        {
            int j;
            if (STATIC_CAST(int, strlen(STATIC_CAST(char *, pValue))) >
                psDBF->panFieldSize[iField])
            {
                j = psDBF->panFieldSize[iField];
                nRetResult = false;
            }
            else
            {
                memset(pabyRec + psDBF->panFieldOffset[iField], ' ',
                       psDBF->panFieldSize[iField]);
                j = STATIC_CAST(int, strlen(STATIC_CAST(char *, pValue)));
            }

            strncpy(REINTERPRET_CAST(char *,
                                     pabyRec + psDBF->panFieldOffset[iField]),
                    STATIC_CAST(const char *, pValue), j);
            break;
        }
    }

    return nRetResult;
}

/************************************************************************/
/*                     DBFWriteAttributeDirectly()                      */
/*                                                                      */
/*      Write an attribute record to the file, but without any          */
/*      reformatting based on type.  The provided buffer is written     */
/*      as is to the field position in the record.                      */
/************************************************************************/

int SHPAPI_CALL DBFWriteAttributeDirectly(DBFHandle psDBF, int hEntity,
                                          int iField, const void *pValue)
{
    /* -------------------------------------------------------------------- */
    /*      Is this a valid record?                                         */
    /* -------------------------------------------------------------------- */
    if (hEntity < 0 || hEntity > psDBF->nRecords)
        return (FALSE);

    if (psDBF->bNoHeader)
        DBFWriteHeader(psDBF);

    /* -------------------------------------------------------------------- */
    /*      Is this a brand new record?                                     */
    /* -------------------------------------------------------------------- */
    if (hEntity == psDBF->nRecords)
    {
        if (!DBFFlushRecord(psDBF))
            return FALSE;

        psDBF->nRecords++;
        for (int i = 0; i < psDBF->nRecordLength; i++)
            psDBF->pszCurrentRecord[i] = ' ';

        psDBF->nCurrentRecord = hEntity;
    }

    /* -------------------------------------------------------------------- */
    /*      Is this an existing record, but different than the last one     */
    /*      we accessed?                                                    */
    /* -------------------------------------------------------------------- */
    if (!DBFLoadRecord(psDBF, hEntity))
        return FALSE;

    if (iField >= 0)
    {
        unsigned char *pabyRec =
            REINTERPRET_CAST(unsigned char *, psDBF->pszCurrentRecord);

        /* -------------------------------------------------------------------- */
        /*      Assign all the record fields.                                   */
        /* -------------------------------------------------------------------- */
        int j;
        if (STATIC_CAST(int, strlen(STATIC_CAST(const char *, pValue))) >
            psDBF->panFieldSize[iField])
            j = psDBF->panFieldSize[iField];
        else
        {
            memset(pabyRec + psDBF->panFieldOffset[iField], ' ',
                   psDBF->panFieldSize[iField]);
            j = STATIC_CAST(int, strlen(STATIC_CAST(const char *, pValue)));
        }

        memcpy(
            REINTERPRET_CAST(char *, pabyRec + psDBF->panFieldOffset[iField]),
            STATIC_CAST(const char *, pValue), j);
    }

    psDBF->bCurrentRecordModified = TRUE;
    psDBF->bUpdated = TRUE;

    return (TRUE);
}

/************************************************************************/
/*                      DBFWriteDoubleAttribute()                       */
/*                                                                      */
/*      Write a double attribute.                                       */
/************************************************************************/

int SHPAPI_CALL DBFWriteDoubleAttribute(DBFHandle psDBF, int iRecord,
                                        int iField, double dValue)
{
    return (DBFWriteAttribute(psDBF, iRecord, iField,
                              STATIC_CAST(void *, &dValue)));
}

/************************************************************************/
/*                      DBFWriteIntegerAttribute()                      */
/*                                                                      */
/*      Write an integer attribute.                                     */
/************************************************************************/

int SHPAPI_CALL DBFWriteIntegerAttribute(DBFHandle psDBF, int iRecord,
                                         int iField, int nValue)
{
    double dValue = nValue;

    return (DBFWriteAttribute(psDBF, iRecord, iField,
                              STATIC_CAST(void *, &dValue)));
}

/************************************************************************/
/*                      DBFWriteStringAttribute()                       */
/*                                                                      */
/*      Write a string attribute.                                       */
/************************************************************************/

int SHPAPI_CALL DBFWriteStringAttribute(DBFHandle psDBF, int iRecord,
                                        int iField, const char *pszValue)
{
    return (
        DBFWriteAttribute(psDBF, iRecord, iField,
                          STATIC_CAST(void *, CONST_CAST(char *, pszValue))));
}

/************************************************************************/
/*                      DBFWriteNULLAttribute()                         */
/*                                                                      */
/*      Write a NULL attribute.                                         */
/************************************************************************/

int SHPAPI_CALL DBFWriteNULLAttribute(DBFHandle psDBF, int iRecord, int iField)
{
    return (DBFWriteAttribute(psDBF, iRecord, iField, SHPLIB_NULLPTR));
}

/************************************************************************/
/*                      DBFWriteLogicalAttribute()                      */
/*                                                                      */
/*      Write a logical attribute.                                      */
/************************************************************************/

int SHPAPI_CALL DBFWriteLogicalAttribute(DBFHandle psDBF, int iRecord,
                                         int iField, const char lValue)
{
    return (
        DBFWriteAttribute(psDBF, iRecord, iField,
                          STATIC_CAST(void *, CONST_CAST(char *, &lValue))));
}

/************************************************************************/
/*                      DBFWriteDateAttribute()                         */
/*                                                                      */
/*      Write a date attribute.                                         */
/************************************************************************/

int SHPAPI_CALL DBFWriteDateAttribute(DBFHandle psDBF, int iRecord, int iField,
                                      const SHPDate *lValue)
{
    if (SHPLIB_NULLPTR == lValue)
        return false;
    /* check for supported digit range, but do not check for valid date */
    if (lValue->year < 0 || lValue->year > 9999)
        return false;
    if (lValue->month < 0 || lValue->month > 99)
        return false;
    if (lValue->day < 0 || lValue->day > 99)
        return false;
    char dateValue[9]; /* "yyyyMMdd\0" */
    snprintf(dateValue, sizeof(dateValue), "%04d%02d%02d", lValue->year,
             lValue->month, lValue->day);
    return (DBFWriteAttributeDirectly(psDBF, iRecord, iField, dateValue));
}

/************************************************************************/
/*                         DBFWriteTuple()                              */
/*                                                                      */
/*      Write an attribute record to the file.                          */
/************************************************************************/

int SHPAPI_CALL DBFWriteTuple(DBFHandle psDBF, int hEntity,
                              const void *pRawTuple)
{
    /* -------------------------------------------------------------------- */
    /*      Is this a valid record?                                         */
    /* -------------------------------------------------------------------- */
    if (hEntity < 0 || hEntity > psDBF->nRecords)
        return (FALSE);

    if (psDBF->bNoHeader)
        DBFWriteHeader(psDBF);

    /* -------------------------------------------------------------------- */
    /*      Is this a brand new record?                                     */
    /* -------------------------------------------------------------------- */
    if (hEntity == psDBF->nRecords)
    {
        if (!DBFFlushRecord(psDBF))
            return FALSE;

        psDBF->nRecords++;
        for (int i = 0; i < psDBF->nRecordLength; i++)
            psDBF->pszCurrentRecord[i] = ' ';

        psDBF->nCurrentRecord = hEntity;
    }

    /* -------------------------------------------------------------------- */
    /*      Is this an existing record, but different than the last one     */
    /*      we accessed?                                                    */
    /* -------------------------------------------------------------------- */
    if (!DBFLoadRecord(psDBF, hEntity))
        return FALSE;

    unsigned char *pabyRec =
        REINTERPRET_CAST(unsigned char *, psDBF->pszCurrentRecord);

    memcpy(pabyRec, pRawTuple, psDBF->nRecordLength);

    psDBF->bCurrentRecordModified = TRUE;
    psDBF->bUpdated = TRUE;

    return (TRUE);
}

/************************************************************************/
/*                            DBFReadTuple()                            */
/*                                                                      */
/*      Read a complete record.  Note that the result is only valid     */
/*      till the next record read for any reason.                       */
/************************************************************************/

const char SHPAPI_CALL1(*) DBFReadTuple(DBFHandle psDBF, int hEntity)
{
    if (hEntity < 0 || hEntity >= psDBF->nRecords)
        return SHPLIB_NULLPTR;

    if (!DBFLoadRecord(psDBF, hEntity))
        return SHPLIB_NULLPTR;

    return STATIC_CAST(const char *, psDBF->pszCurrentRecord);
}

/************************************************************************/
/*                          DBFCloneEmpty()                             */
/*                                                                      */
/*      Create a new .dbf file with same code page and field            */
/*      definitions as the given handle.                                */
/************************************************************************/

DBFHandle SHPAPI_CALL DBFCloneEmpty(const DBFHandle psDBF,
                                    const char *pszFilename)
{
    DBFHandle newDBF =
        DBFCreateLL(pszFilename, psDBF->pszCodePage, &psDBF->sHooks);
    if (newDBF == SHPLIB_NULLPTR)
        return SHPLIB_NULLPTR;

    newDBF->nFields = psDBF->nFields;
    newDBF->nRecordLength = psDBF->nRecordLength;
    newDBF->nHeaderLength = psDBF->nHeaderLength;

    if (psDBF->pszHeader)
    {
        newDBF->pszHeader =
            STATIC_CAST(char *, malloc(XBASE_FLDHDR_SZ * psDBF->nFields));
        memcpy(newDBF->pszHeader, psDBF->pszHeader,
               XBASE_FLDHDR_SZ * psDBF->nFields);
    }

    newDBF->panFieldOffset =
        STATIC_CAST(int *, malloc(sizeof(int) * psDBF->nFields));
    memcpy(newDBF->panFieldOffset, psDBF->panFieldOffset,
           sizeof(int) * psDBF->nFields);
    newDBF->panFieldSize =
        STATIC_CAST(int *, malloc(sizeof(int) * psDBF->nFields));
    memcpy(newDBF->panFieldSize, psDBF->panFieldSize,
           sizeof(int) * psDBF->nFields);
    newDBF->panFieldDecimals =
        STATIC_CAST(int *, malloc(sizeof(int) * psDBF->nFields));
    memcpy(newDBF->panFieldDecimals, psDBF->panFieldDecimals,
           sizeof(int) * psDBF->nFields);
    newDBF->pachFieldType =
        STATIC_CAST(char *, malloc(sizeof(char) * psDBF->nFields));
    memcpy(newDBF->pachFieldType, psDBF->pachFieldType,
           sizeof(char) * psDBF->nFields);

    newDBF->bNoHeader = TRUE;
    newDBF->bUpdated = TRUE;
    newDBF->bWriteEndOfFileChar = psDBF->bWriteEndOfFileChar;

    DBFWriteHeader(newDBF);
    DBFClose(newDBF);

    newDBF = DBFOpen(pszFilename, "rb+");
    newDBF->bWriteEndOfFileChar = psDBF->bWriteEndOfFileChar;

    return (newDBF);
}

/************************************************************************/
/*                       DBFGetNativeFieldType()                        */
/*                                                                      */
/*      Return the DBase field type for the specified field.            */
/*                                                                      */
/*      Value can be one of: 'C' (String), 'D' (Date), 'F' (Float),     */
/*                           'N' (Numeric, with or without decimal),    */
/*                           'L' (Logical),                             */
/*                           'M' (Memo: 10 digits .DBT block ptr)       */
/************************************************************************/

char SHPAPI_CALL DBFGetNativeFieldType(const DBFHandle psDBF, int iField)
{
    if (iField >= 0 && iField < psDBF->nFields)
        return psDBF->pachFieldType[iField];

    return ' ';
}

/************************************************************************/
/*                          DBFGetFieldIndex()                          */
/*                                                                      */
/*      Get the index number for a field in a .dbf file.                */
/*                                                                      */
/*      Contributed by Jim Matthews.                                    */
/************************************************************************/

int SHPAPI_CALL DBFGetFieldIndex(const DBFHandle psDBF,
                                 const char *pszFieldName)
{
    char name[XBASE_FLDNAME_LEN_READ + 1];

    for (int i = 0; i < DBFGetFieldCount(psDBF); i++)
    {
        DBFGetFieldInfo(psDBF, i, name, SHPLIB_NULLPTR, SHPLIB_NULLPTR);
        if (!STRCASECMP(pszFieldName, name))
            return (i);
    }
    return (-1);
}

/************************************************************************/
/*                         DBFIsRecordDeleted()                         */
/*                                                                      */
/*      Returns TRUE if the indicated record is deleted, otherwise      */
/*      it returns FALSE.                                               */
/************************************************************************/

int SHPAPI_CALL DBFIsRecordDeleted(const DBFHandle psDBF, int iShape)
{
    /* -------------------------------------------------------------------- */
    /*      Verify selection.                                               */
    /* -------------------------------------------------------------------- */
    if (iShape < 0 || iShape >= psDBF->nRecords)
        return TRUE;

    /* -------------------------------------------------------------------- */
    /*      Have we read the record?                                        */
    /* -------------------------------------------------------------------- */
    if (!DBFLoadRecord(psDBF, iShape))
        return FALSE;

    /* -------------------------------------------------------------------- */
    /*      '*' means deleted.                                              */
    /* -------------------------------------------------------------------- */
    return psDBF->pszCurrentRecord[0] == '*';
}

/************************************************************************/
/*                        DBFMarkRecordDeleted()                        */
/************************************************************************/

int SHPAPI_CALL DBFMarkRecordDeleted(DBFHandle psDBF, int iShape,
                                     int bIsDeleted)
{
    /* -------------------------------------------------------------------- */
    /*      Verify selection.                                               */
    /* -------------------------------------------------------------------- */
    if (iShape < 0 || iShape >= psDBF->nRecords)
        return FALSE;

    /* -------------------------------------------------------------------- */
    /*      Is this an existing record, but different than the last one     */
    /*      we accessed?                                                    */
    /* -------------------------------------------------------------------- */
    if (!DBFLoadRecord(psDBF, iShape))
        return FALSE;

    /* -------------------------------------------------------------------- */
    /*      Assign value, marking record as dirty if it changes.            */
    /* -------------------------------------------------------------------- */
    const char chNewFlag = bIsDeleted ? '*' : ' ';

    if (psDBF->pszCurrentRecord[0] != chNewFlag)
    {
        psDBF->bCurrentRecordModified = TRUE;
        psDBF->bUpdated = TRUE;
        psDBF->pszCurrentRecord[0] = chNewFlag;
    }

    return TRUE;
}

/************************************************************************/
/*                            DBFGetCodePage                            */
/************************************************************************/

const char SHPAPI_CALL1(*) DBFGetCodePage(const DBFHandle psDBF)
{
    if (psDBF == SHPLIB_NULLPTR)
        return SHPLIB_NULLPTR;
    return psDBF->pszCodePage;
}

/************************************************************************/
/*                          DBFDeleteField()                            */
/*                                                                      */
/*      Remove a field from a .dbf file                                 */
/************************************************************************/

int SHPAPI_CALL DBFDeleteField(DBFHandle psDBF, int iField)
{
    if (iField < 0 || iField >= psDBF->nFields)
        return FALSE;

    /* make sure that everything is written in .dbf */
    if (!DBFFlushRecord(psDBF))
        return FALSE;

    /* get information about field to be deleted */
    int nOldRecordLength = psDBF->nRecordLength;
    int nOldHeaderLength = psDBF->nHeaderLength;
    int nDeletedFieldOffset = psDBF->panFieldOffset[iField];
    int nDeletedFieldSize = psDBF->panFieldSize[iField];

    /* update fields info */
    for (int i = iField + 1; i < psDBF->nFields; i++)
    {
        psDBF->panFieldOffset[i - 1] =
            psDBF->panFieldOffset[i] - nDeletedFieldSize;
        psDBF->panFieldSize[i - 1] = psDBF->panFieldSize[i];
        psDBF->panFieldDecimals[i - 1] = psDBF->panFieldDecimals[i];
        psDBF->pachFieldType[i - 1] = psDBF->pachFieldType[i];
    }

    /* resize fields arrays */
    psDBF->nFields--;

    psDBF->panFieldOffset = STATIC_CAST(
        int *, realloc(psDBF->panFieldOffset, sizeof(int) * psDBF->nFields));

    psDBF->panFieldSize = STATIC_CAST(
        int *, realloc(psDBF->panFieldSize, sizeof(int) * psDBF->nFields));

    psDBF->panFieldDecimals = STATIC_CAST(
        int *, realloc(psDBF->panFieldDecimals, sizeof(int) * psDBF->nFields));

    psDBF->pachFieldType = STATIC_CAST(
        char *, realloc(psDBF->pachFieldType, sizeof(char) * psDBF->nFields));

    /* update header information */
    psDBF->nHeaderLength -= XBASE_FLDHDR_SZ;
    psDBF->nRecordLength -= nDeletedFieldSize;

    /* overwrite field information in header */
    memmove(psDBF->pszHeader + iField * XBASE_FLDHDR_SZ,
            psDBF->pszHeader + (iField + 1) * XBASE_FLDHDR_SZ,
            sizeof(char) * (psDBF->nFields - iField) * XBASE_FLDHDR_SZ);

    psDBF->pszHeader = STATIC_CAST(
        char *, realloc(psDBF->pszHeader, psDBF->nFields * XBASE_FLDHDR_SZ));

    /* update size of current record appropriately */
    psDBF->pszCurrentRecord = STATIC_CAST(
        char *, realloc(psDBF->pszCurrentRecord, psDBF->nRecordLength));

    /* we're done if we're dealing with not yet created .dbf */
    if (psDBF->bNoHeader && psDBF->nRecords == 0)
        return TRUE;

    /* force update of header with new header and record length */
    psDBF->bNoHeader = TRUE;
    DBFUpdateHeader(psDBF);

    /* alloc record */
    char *pszRecord =
        STATIC_CAST(char *, malloc(sizeof(char) * nOldRecordLength));

    /* shift records to their new positions */
    for (int iRecord = 0; iRecord < psDBF->nRecords; iRecord++)
    {
        SAOffset nRecordOffset =
            nOldRecordLength * STATIC_CAST(SAOffset, iRecord) +
            nOldHeaderLength;

        /* load record */
        psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
        if (psDBF->sHooks.FRead(pszRecord, nOldRecordLength, 1, psDBF->fp) != 1)
        {
            free(pszRecord);
            return FALSE;
        }

        nRecordOffset = psDBF->nRecordLength * STATIC_CAST(SAOffset, iRecord) +
                        psDBF->nHeaderLength;

        /* move record in two steps */
        psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
        psDBF->sHooks.FWrite(pszRecord, nDeletedFieldOffset, 1, psDBF->fp);
        psDBF->sHooks.FWrite(
            pszRecord + nDeletedFieldOffset + nDeletedFieldSize,
            nOldRecordLength - nDeletedFieldOffset - nDeletedFieldSize, 1,
            psDBF->fp);
    }

    if (psDBF->bWriteEndOfFileChar)
    {
        char ch = END_OF_FILE_CHARACTER;
        SAOffset nEOFOffset =
            psDBF->nRecordLength * STATIC_CAST(SAOffset, psDBF->nRecords) +
            psDBF->nHeaderLength;

        psDBF->sHooks.FSeek(psDBF->fp, nEOFOffset, 0);
        psDBF->sHooks.FWrite(&ch, 1, 1, psDBF->fp);
    }

    /* TODO: truncate file */

    /* free record */
    free(pszRecord);

    psDBF->nCurrentRecord = -1;
    psDBF->bCurrentRecordModified = FALSE;
    psDBF->bUpdated = TRUE;

    return TRUE;
}

/************************************************************************/
/*                          DBFReorderFields()                          */
/*                                                                      */
/*      Reorder the fields of a .dbf file                               */
/*                                                                      */
/* panMap must be exactly psDBF->nFields long and be a permutation      */
/* of [0, psDBF->nFields-1]. This assumption will not be asserted in the*/
/* code of DBFReorderFields.                                            */
/************************************************************************/

int SHPAPI_CALL DBFReorderFields(DBFHandle psDBF, const int *panMap)
{
    if (psDBF->nFields == 0)
        return TRUE;

    /* make sure that everything is written in .dbf */
    if (!DBFFlushRecord(psDBF))
        return FALSE;

    /* a simple malloc() would be enough, but calloc() helps clang static
     * analyzer */
    int *panFieldOffsetNew =
        STATIC_CAST(int *, calloc(psDBF->nFields, sizeof(int)));
    int *panFieldSizeNew =
        STATIC_CAST(int *, calloc(psDBF->nFields, sizeof(int)));
    int *panFieldDecimalsNew =
        STATIC_CAST(int *, calloc(psDBF->nFields, sizeof(int)));
    char *pachFieldTypeNew =
        STATIC_CAST(char *, calloc(psDBF->nFields, sizeof(char)));
    char *pszHeaderNew = STATIC_CAST(
        char *, malloc(sizeof(char) * XBASE_FLDHDR_SZ * psDBF->nFields));
    char *pszRecord = SHPLIB_NULLPTR;
    char *pszRecordNew = SHPLIB_NULLPTR;
    if (!(psDBF->bNoHeader && psDBF->nRecords == 0))
    {
        /* alloc record */
        pszRecord =
            STATIC_CAST(char *, malloc(sizeof(char) * psDBF->nRecordLength));
        pszRecordNew =
            STATIC_CAST(char *, malloc(sizeof(char) * psDBF->nRecordLength));
    }
    if (!panFieldOffsetNew || !panFieldSizeNew || !panFieldDecimalsNew ||
        !pachFieldTypeNew || !pszHeaderNew ||
        (!(psDBF->bNoHeader && psDBF->nRecords == 0) &&
         (!pszRecord || !pszRecordNew)))
    {
        free(panFieldOffsetNew);
        free(panFieldSizeNew);
        free(panFieldDecimalsNew);
        free(pachFieldTypeNew);
        free(pszHeaderNew);
        free(pszRecord);
        free(pszRecordNew);
        psDBF->sHooks.Error("Out of memory");
        return FALSE;
    }

    /* shuffle fields definitions */
    for (int i = 0; i < psDBF->nFields; i++)
    {
        panFieldSizeNew[i] = psDBF->panFieldSize[panMap[i]];
        panFieldDecimalsNew[i] = psDBF->panFieldDecimals[panMap[i]];
        pachFieldTypeNew[i] = psDBF->pachFieldType[panMap[i]];
        memcpy(pszHeaderNew + i * XBASE_FLDHDR_SZ,
               psDBF->pszHeader + panMap[i] * XBASE_FLDHDR_SZ, XBASE_FLDHDR_SZ);
    }
    panFieldOffsetNew[0] = 1;
    for (int i = 1; i < psDBF->nFields; i++)
    {
        panFieldOffsetNew[i] =
            panFieldOffsetNew[i - 1] + panFieldSizeNew[i - 1];
    }

    free(psDBF->pszHeader);
    psDBF->pszHeader = pszHeaderNew;

    bool errorAbort = false;

    /* we're done if we're dealing with not yet created .dbf */
    if (!(psDBF->bNoHeader && psDBF->nRecords == 0))
    {
        /* force update of header with new header and record length */
        psDBF->bNoHeader = TRUE;
        DBFUpdateHeader(psDBF);

        /* shuffle fields in records */
        for (int iRecord = 0; iRecord < psDBF->nRecords; iRecord++)
        {
            const SAOffset nRecordOffset =
                psDBF->nRecordLength * STATIC_CAST(SAOffset, iRecord) +
                psDBF->nHeaderLength;

            /* load record */
            psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
            if (psDBF->sHooks.FRead(pszRecord, psDBF->nRecordLength, 1,
                                    psDBF->fp) != 1)
            {
                errorAbort = true;
                break;
            }

            pszRecordNew[0] = pszRecord[0];

            for (int i = 0; i < psDBF->nFields; i++)
            {
                memcpy(pszRecordNew + panFieldOffsetNew[i],
                       pszRecord + psDBF->panFieldOffset[panMap[i]],
                       psDBF->panFieldSize[panMap[i]]);
            }

            /* write record */
            psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
            psDBF->sHooks.FWrite(pszRecordNew, psDBF->nRecordLength, 1,
                                 psDBF->fp);
        }
    }

    /* free record */
    free(pszRecord);
    free(pszRecordNew);

    if (errorAbort)
    {
        free(panFieldOffsetNew);
        free(panFieldSizeNew);
        free(panFieldDecimalsNew);
        free(pachFieldTypeNew);
        psDBF->nCurrentRecord = -1;
        psDBF->bCurrentRecordModified = FALSE;
        psDBF->bUpdated = FALSE;
        return FALSE;
    }

    free(psDBF->panFieldOffset);
    free(psDBF->panFieldSize);
    free(psDBF->panFieldDecimals);
    free(psDBF->pachFieldType);

    psDBF->panFieldOffset = panFieldOffsetNew;
    psDBF->panFieldSize = panFieldSizeNew;
    psDBF->panFieldDecimals = panFieldDecimalsNew;
    psDBF->pachFieldType = pachFieldTypeNew;

    psDBF->nCurrentRecord = -1;
    psDBF->bCurrentRecordModified = FALSE;
    psDBF->bUpdated = TRUE;

    return TRUE;
}

/************************************************************************/
/*                          DBFAlterFieldDefn()                         */
/*                                                                      */
/*      Alter a field definition in a .dbf file                         */
/************************************************************************/

int SHPAPI_CALL DBFAlterFieldDefn(DBFHandle psDBF, int iField,
                                  const char *pszFieldName, char chType,
                                  int nWidth, int nDecimals)
{
    if (iField < 0 || iField >= psDBF->nFields)
        return FALSE;

    /* make sure that everything is written in .dbf */
    if (!DBFFlushRecord(psDBF))
        return FALSE;

    const char chFieldFill = DBFGetNullCharacter(chType);

    const char chOldType = psDBF->pachFieldType[iField];
    const int nOffset = psDBF->panFieldOffset[iField];
    const int nOldWidth = psDBF->panFieldSize[iField];
    const int nOldRecordLength = psDBF->nRecordLength;

    /* -------------------------------------------------------------------- */
    /*      Do some checking to ensure we can add records to this file.     */
    /* -------------------------------------------------------------------- */
    if (nWidth < 1)
        return -1;

    if (nWidth > XBASE_FLD_MAX_WIDTH)
        nWidth = XBASE_FLD_MAX_WIDTH;

    char *pszRecord = STATIC_CAST(
        char *, malloc(nOldRecordLength +
                       ((nWidth > nOldWidth) ? nWidth - nOldWidth : 0)));
    char *pszOldField = STATIC_CAST(char *, malloc(nOldWidth + 1));
    if (!pszRecord || !pszOldField)
    {
        free(pszRecord);
        free(pszOldField);
        return FALSE;
    }

    if (nWidth != nOldWidth)
    {
        char *pszCurrentRecordNew = STATIC_CAST(
            char *, realloc(psDBF->pszCurrentRecord,
                            psDBF->nRecordLength + nWidth - nOldWidth));
        if (!pszCurrentRecordNew)
        {
            free(pszRecord);
            free(pszOldField);
            return FALSE;
        }
        psDBF->pszCurrentRecord = pszCurrentRecordNew;
    }

    /* -------------------------------------------------------------------- */
    /*      Assign the new field information fields.                        */
    /* -------------------------------------------------------------------- */
    psDBF->panFieldSize[iField] = nWidth;
    psDBF->panFieldDecimals[iField] = nDecimals;
    psDBF->pachFieldType[iField] = chType;

    /* -------------------------------------------------------------------- */
    /*      Update the header information.                                  */
    /* -------------------------------------------------------------------- */
    char *pszFInfo = psDBF->pszHeader + XBASE_FLDHDR_SZ * iField;

    for (int i = 0; i < XBASE_FLDHDR_SZ; i++)
        pszFInfo[i] = '\0';

    strncpy(pszFInfo, pszFieldName, XBASE_FLDNAME_LEN_WRITE);

    pszFInfo[11] = psDBF->pachFieldType[iField];

    if (chType == 'C')
    {
        pszFInfo[16] = STATIC_CAST(unsigned char, nWidth % 256);
        pszFInfo[17] = STATIC_CAST(unsigned char, nWidth / 256);
    }
    else
    {
        pszFInfo[16] = STATIC_CAST(unsigned char, nWidth);
        pszFInfo[17] = STATIC_CAST(unsigned char, nDecimals);
    }

    /* -------------------------------------------------------------------- */
    /*      Update offsets                                                  */
    /* -------------------------------------------------------------------- */
    if (nWidth != nOldWidth)
    {
        for (int i = iField + 1; i < psDBF->nFields; i++)
            psDBF->panFieldOffset[i] += nWidth - nOldWidth;
        psDBF->nRecordLength += nWidth - nOldWidth;
    }

    /* we're done if we're dealing with not yet created .dbf */
    if (psDBF->bNoHeader && psDBF->nRecords == 0)
    {
        free(pszRecord);
        free(pszOldField);
        return TRUE;
    }

    /* force update of header with new header and record length */
    psDBF->bNoHeader = TRUE;
    DBFUpdateHeader(psDBF);

    bool errorAbort = false;

    if (nWidth < nOldWidth || (nWidth == nOldWidth && chType != chOldType))
    {
        pszOldField[nOldWidth] = 0;

        /* move records to their new positions */
        for (int iRecord = 0; iRecord < psDBF->nRecords; iRecord++)
        {
            SAOffset nRecordOffset =
                nOldRecordLength * STATIC_CAST(SAOffset, iRecord) +
                psDBF->nHeaderLength;

            /* load record */
            psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
            if (psDBF->sHooks.FRead(pszRecord, nOldRecordLength, 1,
                                    psDBF->fp) != 1)
            {
                errorAbort = true;
                break;
            }

            memcpy(pszOldField, pszRecord + nOffset, nOldWidth);
            const bool bIsNULL =
                DBFIsValueNULL(chOldType, pszOldField, nOldWidth);

            if (nWidth != nOldWidth)
            {
                if ((chOldType == 'N' || chOldType == 'F' ||
                     chOldType == 'D') &&
                    pszOldField[0] == ' ')
                {
                    /* Strip leading spaces when truncating a numeric field */
                    memmove(pszRecord + nOffset,
                            pszRecord + nOffset + nOldWidth - nWidth, nWidth);
                }
                if (nOffset + nOldWidth < nOldRecordLength)
                {
                    memmove(pszRecord + nOffset + nWidth,
                            pszRecord + nOffset + nOldWidth,
                            nOldRecordLength - (nOffset + nOldWidth));
                }
            }

            /* Convert null value to the appropriate value of the new type */
            if (bIsNULL)
            {
                memset(pszRecord + nOffset, chFieldFill, nWidth);
            }

            nRecordOffset =
                psDBF->nRecordLength * STATIC_CAST(SAOffset, iRecord) +
                psDBF->nHeaderLength;

            /* write record */
            psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
            psDBF->sHooks.FWrite(pszRecord, psDBF->nRecordLength, 1, psDBF->fp);
        }

        if (!errorAbort && psDBF->bWriteEndOfFileChar)
        {
            char ch = END_OF_FILE_CHARACTER;

            SAOffset nRecordOffset =
                psDBF->nRecordLength * STATIC_CAST(SAOffset, psDBF->nRecords) +
                psDBF->nHeaderLength;

            psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
            psDBF->sHooks.FWrite(&ch, 1, 1, psDBF->fp);
        }
        /* TODO: truncate file */
    }
    else if (nWidth > nOldWidth)
    {
        pszOldField[nOldWidth] = 0;

        /* move records to their new positions */
        for (int iRecord = psDBF->nRecords - 1; iRecord >= 0; iRecord--)
        {
            SAOffset nRecordOffset =
                nOldRecordLength * STATIC_CAST(SAOffset, iRecord) +
                psDBF->nHeaderLength;

            /* load record */
            psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
            if (psDBF->sHooks.FRead(pszRecord, nOldRecordLength, 1,
                                    psDBF->fp) != 1)
            {
                errorAbort = true;
                break;
            }

            memcpy(pszOldField, pszRecord + nOffset, nOldWidth);
            const bool bIsNULL =
                DBFIsValueNULL(chOldType, pszOldField, nOldWidth);

            if (nOffset + nOldWidth < nOldRecordLength)
            {
                memmove(pszRecord + nOffset + nWidth,
                        pszRecord + nOffset + nOldWidth,
                        nOldRecordLength - (nOffset + nOldWidth));
            }

            /* Convert null value to the appropriate value of the new type */
            if (bIsNULL)
            {
                memset(pszRecord + nOffset, chFieldFill, nWidth);
            }
            else
            {
                if ((chOldType == 'N' || chOldType == 'F'))
                {
                    /* Add leading spaces when expanding a numeric field */
                    memmove(pszRecord + nOffset + nWidth - nOldWidth,
                            pszRecord + nOffset, nOldWidth);
                    memset(pszRecord + nOffset, ' ', nWidth - nOldWidth);
                }
                else
                {
                    /* Add trailing spaces */
                    memset(pszRecord + nOffset + nOldWidth, ' ',
                           nWidth - nOldWidth);
                }
            }

            nRecordOffset =
                psDBF->nRecordLength * STATIC_CAST(SAOffset, iRecord) +
                psDBF->nHeaderLength;

            /* write record */
            psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
            psDBF->sHooks.FWrite(pszRecord, psDBF->nRecordLength, 1, psDBF->fp);
        }

        if (!errorAbort && psDBF->bWriteEndOfFileChar)
        {
            const char ch = END_OF_FILE_CHARACTER;

            SAOffset nRecordOffset =
                psDBF->nRecordLength * STATIC_CAST(SAOffset, psDBF->nRecords) +
                psDBF->nHeaderLength;

            psDBF->sHooks.FSeek(psDBF->fp, nRecordOffset, 0);
            psDBF->sHooks.FWrite(&ch, 1, 1, psDBF->fp);
        }
    }

    free(pszRecord);
    free(pszOldField);

    if (errorAbort)
    {
        psDBF->nCurrentRecord = -1;
        psDBF->bCurrentRecordModified = TRUE;
        psDBF->bUpdated = FALSE;

        return FALSE;
    }
    psDBF->nCurrentRecord = -1;
    psDBF->bCurrentRecordModified = FALSE;
    psDBF->bUpdated = TRUE;

    return TRUE;
}

/************************************************************************/
/*                      DBFSetWriteEndOfFileChar()                      */
/************************************************************************/

void SHPAPI_CALL DBFSetWriteEndOfFileChar(DBFHandle psDBF, int bWriteFlag)
{
    psDBF->bWriteEndOfFileChar = bWriteFlag;
}

Coverage Report

Created: 2026-05-16 08:20