/**

 * WinPR: Windows Portable Runtime

 * Clipboard Functions: POSIX file handling

 *

 * Copyright 2017 Alexei Lozovsky <a.lozovsky@gmail.com>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <winpr/config.h>

#include <winpr/platform.h>

WINPR_PRAGMA_DIAG_PUSH

WINPR_PRAGMA_DIAG_IGNORED_RESERVED_ID_MACRO

WINPR_PRAGMA_DIAG_IGNORED_UNUSED_MACRO

#define _FILE_OFFSET_BITS 64 // NOLINT(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp)

WINPR_PRAGMA_DIAG_POP

#include <errno.h>

#include <winpr/wtypes.h>

#include <winpr/crt.h>

#include <winpr/clipboard.h>

#include <winpr/collections.h>

#include <winpr/file.h>

#include <winpr/shell.h>

#include <winpr/string.h>

#include <winpr/wlog.h>

#include <winpr/path.h>

#include <winpr/print.h>

#include "clipboard.h"

#include "synthetic_file.h"

#include "../log.h"

#define TAG WINPR_TAG("clipboard.synthetic.file")

static const char* mime_uri_list = "text/uri-list";

static const char* mime_FileGroupDescriptorW = "FileGroupDescriptorW";

static const char* mime_gnome_copied_files = "x-special/gnome-copied-files";

static const char* mime_mate_copied_files = "x-special/mate-copied-files";

struct synthetic_file

{

  WCHAR* local_name;

  WCHAR* remote_name;

  HANDLE fd;

  INT64 offset;

  DWORD dwFileAttributes;

  FILETIME ftCreationTime;

  FILETIME ftLastAccessTime;

  FILETIME ftLastWriteTime;

  DWORD nFileSizeHigh;

  DWORD nFileSizeLow;

};

void free_synthetic_file(struct synthetic_file* file);

static struct synthetic_file* make_synthetic_file(const WCHAR* local_name, const WCHAR* remote_name)

{

  struct synthetic_file* file = NULL;

  WIN32_FIND_DATAW fd = { 0 };

  HANDLE hFind = NULL;

  WINPR_ASSERT(local_name);

  WINPR_ASSERT(remote_name);

  hFind = FindFirstFileW(local_name, &fd);

  if (INVALID_HANDLE_VALUE == hFind)

  {

    WLog_ERR(TAG, "FindFirstFile failed (%" PRIu32 ")", GetLastError());

    return NULL;

  }

  FindClose(hFind);

  file = calloc(1, sizeof(*file));

  if (!file)

    return NULL;

  file->fd = INVALID_HANDLE_VALUE;

  file->offset = 0;

  file->local_name = _wcsdup(local_name);

  if (!file->local_name)

    goto fail;

  file->remote_name = _wcsdup(remote_name);

  if (!file->remote_name)

    goto fail;

  {

    const size_t len = _wcslen(file->remote_name);

    PathCchConvertStyleW(file->remote_name, len, PATH_STYLE_WINDOWS);

  }

  file->dwFileAttributes = fd.dwFileAttributes;

  file->ftCreationTime = fd.ftCreationTime;

  file->ftLastWriteTime = fd.ftLastWriteTime;

  file->ftLastAccessTime = fd.ftLastAccessTime;

  file->nFileSizeHigh = fd.nFileSizeHigh;

  file->nFileSizeLow = fd.nFileSizeLow;

  return file;

fail:

  free_synthetic_file(file);

  return NULL;

}

static UINT synthetic_file_read_close(struct synthetic_file* file, BOOL force);

void free_synthetic_file(struct synthetic_file* file)

{

  if (!file)

    return;

  synthetic_file_read_close(file, TRUE);

  free(file->local_name);

  free(file->remote_name);

  free(file);

}

/*

 * Note that the function converts a single file name component,

 * it does not take care of component separators.

 */

static WCHAR* convert_local_name_component_to_remote(wClipboard* clipboard, const WCHAR* local_name)

{

  wClipboardDelegate* delegate = ClipboardGetDelegate(clipboard);

  WCHAR* remote_name = NULL;

  WINPR_ASSERT(delegate);

  remote_name = _wcsdup(local_name);

  /*

   * Some file names are not valid on Windows. Check for these now

   * so that we won't get ourselves into a trouble later as such names

   * are known to crash some Windows shells when pasted via clipboard.

   *

   * The IsFileNameComponentValid callback can be overridden by the API

   * user, if it is known, that the connected peer is not on the

   * Windows platform.

   */

  if (!delegate->IsFileNameComponentValid(remote_name))

  {

    WLog_ERR(TAG, "invalid file name component: %s", local_name);

    goto error;

  }

  return remote_name;

error:

  free(remote_name);

  return NULL;

}

static WCHAR* concat_file_name(const WCHAR* dir, const WCHAR* file)

{

  size_t len_dir = 0;

  size_t len_file = 0;

  const WCHAR slash = '/';

  WCHAR* buffer = NULL;

  WINPR_ASSERT(dir);

  WINPR_ASSERT(file);

  len_dir = _wcslen(dir);

  len_file = _wcslen(file);

  buffer = calloc(len_dir + 1 + len_file + 2, sizeof(WCHAR));

  if (!buffer)

    return NULL;

  memcpy(buffer, dir, len_dir * sizeof(WCHAR));

  buffer[len_dir] = slash;

  memcpy(buffer + len_dir + 1, file, len_file * sizeof(WCHAR));

  return buffer;

}

static BOOL add_file_to_list(wClipboard* clipboard, const WCHAR* local_name,

                             const WCHAR* remote_name, wArrayList* files);

static BOOL add_directory_entry_to_list(wClipboard* clipboard, const WCHAR* local_dir_name,

                                        const WCHAR* remote_dir_name,

                                        const LPWIN32_FIND_DATAW pFileData, wArrayList* files)

{

  BOOL result = FALSE;

  WCHAR* local_name = NULL;

  WCHAR* remote_name = NULL;

  WCHAR* remote_base_name = NULL;

  WCHAR dotbuffer[6] = { 0 };

  WCHAR dotdotbuffer[6] = { 0 };

  const WCHAR* dot = InitializeConstWCharFromUtf8(".", dotbuffer, ARRAYSIZE(dotbuffer));

  const WCHAR* dotdot = InitializeConstWCharFromUtf8("..", dotdotbuffer, ARRAYSIZE(dotdotbuffer));

  WINPR_ASSERT(clipboard);

  WINPR_ASSERT(local_dir_name);

  WINPR_ASSERT(remote_dir_name);

  WINPR_ASSERT(pFileData);

  WINPR_ASSERT(files);

  /* Skip special directory entries. */

  if ((_wcscmp(pFileData->cFileName, dot) == 0) || (_wcscmp(pFileData->cFileName, dotdot) == 0))

    return TRUE;

  remote_base_name = convert_local_name_component_to_remote(clipboard, pFileData->cFileName);

  if (!remote_base_name)

    return FALSE;

  local_name = concat_file_name(local_dir_name, pFileData->cFileName);

  remote_name = concat_file_name(remote_dir_name, remote_base_name);

  if (local_name && remote_name)

    result = add_file_to_list(clipboard, local_name, remote_name, files);

  free(remote_base_name);

  free(remote_name);

  free(local_name);

  return result;

}

static BOOL do_add_directory_contents_to_list(wClipboard* clipboard, const WCHAR* local_name,

                                              const WCHAR* remote_name, WCHAR* namebuf,

                                              wArrayList* files)

{

  WINPR_ASSERT(clipboard);

  WINPR_ASSERT(local_name);

  WINPR_ASSERT(remote_name);

  WINPR_ASSERT(files);

  WINPR_ASSERT(namebuf);

  WIN32_FIND_DATAW FindData = { 0 };

  HANDLE hFind = FindFirstFileW(namebuf, &FindData);

  if (INVALID_HANDLE_VALUE == hFind)

  {

    WLog_ERR(TAG, "FindFirstFile failed (%" PRIu32 ")", GetLastError());

    return FALSE;

  }

  while (TRUE)

  {

    if (!add_directory_entry_to_list(clipboard, local_name, remote_name, &FindData, files))

    {

      FindClose(hFind);

      return FALSE;

    }

    BOOL bRet = FindNextFileW(hFind, &FindData);

    if (!bRet)

    {

      FindClose(hFind);

      if (ERROR_NO_MORE_FILES == GetLastError())

        return TRUE;

      WLog_WARN(TAG, "FindNextFile failed (%" PRIu32 ")", GetLastError());

      return FALSE;

    }

  }

  return TRUE;

}

static BOOL add_directory_contents_to_list(wClipboard* clipboard, const WCHAR* local_name,

                                           const WCHAR* remote_name, wArrayList* files)

{

  BOOL result = FALSE;

  union

  {

    const char* c;

    const WCHAR* w;

  } wildcard;

  const char buffer[6] = { '/', '\0', '*', '\0', '\0', '\0' };

  wildcard.c = buffer;

  const size_t wildcardLen = ARRAYSIZE(buffer) / sizeof(WCHAR);

  WINPR_ASSERT(clipboard);

  WINPR_ASSERT(local_name);

  WINPR_ASSERT(remote_name);

  WINPR_ASSERT(files);

  size_t len = _wcslen(local_name);

  WCHAR* namebuf = calloc(len + wildcardLen, sizeof(WCHAR));

  if (!namebuf)

    return FALSE;

  _wcsncat(namebuf, local_name, len);

  _wcsncat(namebuf, wildcard.w, wildcardLen);

  result = do_add_directory_contents_to_list(clipboard, local_name, remote_name, namebuf, files);

  free(namebuf);

  return result;

}

static BOOL add_file_to_list(wClipboard* clipboard, const WCHAR* local_name,

                             const WCHAR* remote_name, wArrayList* files)

{

  struct synthetic_file* file = NULL;

  WINPR_ASSERT(clipboard);

  WINPR_ASSERT(local_name);

  WINPR_ASSERT(remote_name);

  WINPR_ASSERT(files);

  file = make_synthetic_file(local_name, remote_name);

  if (!file)

    return FALSE;

  if (!ArrayList_Append(files, file))

  {

    free_synthetic_file(file);

    return FALSE;

  }

  if (file->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)

  {

    /*

     * This is effectively a recursive call, but we do not track

     * recursion depth, thus filesystem loops can cause a crash.

     */

    if (!add_directory_contents_to_list(clipboard, local_name, remote_name, files))

      return FALSE;

  }

  return TRUE;

}

static const WCHAR* get_basename(const WCHAR* name)

{

  const WCHAR* c = name;

  const WCHAR* last_name = name;

  const WCHAR slash = '/';

  WINPR_ASSERT(name);

  while (*c++)

  {

    if (*c == slash)

      last_name = c + 1;

  }

  return last_name;

}

static BOOL process_file_name(wClipboard* clipboard, const WCHAR* local_name, wArrayList* files)

{

  BOOL result = FALSE;

  const WCHAR* base_name = NULL;

  WCHAR* remote_name = NULL;

  WINPR_ASSERT(clipboard);

  WINPR_ASSERT(local_name);

  WINPR_ASSERT(files);

  /*

   * Start with the base name of the file. text/uri-list contains the

   * exact files selected by the user, and we want the remote files

   * to have names relative to that selection.

   */

  base_name = get_basename(local_name);

  remote_name = convert_local_name_component_to_remote(clipboard, base_name);

  if (!remote_name)

    return FALSE;

  result = add_file_to_list(clipboard, local_name, remote_name, files);

  free(remote_name);

  return result;

}

static BOOL process_uri(wClipboard* clipboard, const char* uri, size_t uri_len)

{

  // URI is specified by RFC 8089: https://datatracker.ietf.org/doc/html/rfc8089

  BOOL result = FALSE;

  char* name = NULL;

  WINPR_ASSERT(clipboard);

  name = parse_uri_to_local_file(uri, uri_len);

  if (name)

  {

    WCHAR* wname = NULL;

    /*

     * Note that local file names are not actually guaranteed to be

     * encoded in UTF-8. Filesystems and users can use whatever they

     * want. The OS does not care, aside from special treatment of

     * '\0' and '/' bytes. But we need to make some decision here.

     * Assuming UTF-8 is currently the most sane thing.

     */

    wname = ConvertUtf8ToWCharAlloc(name, NULL);

    if (wname)

      result = process_file_name(clipboard, wname, clipboard->localFiles);

    free(name);

    free(wname);

  }

  return result;

}

static BOOL process_uri_list(wClipboard* clipboard, const char* data, size_t length)

{

  const char* cur = data;

  const char* lim = data + length;

  WINPR_ASSERT(clipboard);

  WINPR_ASSERT(data);

  WLog_VRB(TAG, "processing URI list:\n%.*s", length, data);

  ArrayList_Clear(clipboard->localFiles);

  /*

   * The "text/uri-list" Internet Media Type is specified by RFC 2483.

   *

   * While the RFCs 2046 and 2483 require the lines of text/... formats

   * to be terminated by CRLF sequence, be prepared for those who don't

   * read the spec, use plain LFs, and don't leave the trailing CRLF.

   */

  while (cur < lim)

  {

    BOOL comment = (*cur == '#');

    const char* start = cur;

    const char* stop = cur;

    for (; stop < lim; stop++)

    {

      if (*stop == '\r')

      {

        if ((stop + 1 < lim) && (*(stop + 1) == '\n'))

          cur = stop + 2;

        else

          cur = stop + 1;

        break;

      }

      if (*stop == '\n')

      {

        cur = stop + 1;

        break;

      }

    }

    if (stop == lim)

    {

      if (strnlen(start, WINPR_ASSERTING_INT_CAST(size_t, stop - start)) < 1)

        return TRUE;

      cur = lim;

    }

    if (comment)

      continue;

    if (!process_uri(clipboard, start, WINPR_ASSERTING_INT_CAST(size_t, stop - start)))

      return FALSE;

  }

  return TRUE;

}

static BOOL convert_local_file_to_filedescriptor(const struct synthetic_file* file,

                                                 FILEDESCRIPTORW* descriptor)

{

  size_t remote_len = 0;

  WINPR_ASSERT(file);

  WINPR_ASSERT(descriptor);

  descriptor->dwFlags = FD_ATTRIBUTES | FD_FILESIZE | FD_WRITESTIME | FD_PROGRESSUI;

  if (file->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)

  {

    descriptor->dwFileAttributes = FILE_ATTRIBUTE_DIRECTORY;

    descriptor->nFileSizeLow = 0;

    descriptor->nFileSizeHigh = 0;

  }

  else

  {

    descriptor->dwFileAttributes = FILE_ATTRIBUTE_NORMAL;

    descriptor->nFileSizeLow = file->nFileSizeLow;

    descriptor->nFileSizeHigh = file->nFileSizeHigh;

  }

  descriptor->ftLastWriteTime = file->ftLastWriteTime;

  remote_len = _wcsnlen(file->remote_name, ARRAYSIZE(descriptor->cFileName));

  if (remote_len >= ARRAYSIZE(descriptor->cFileName))

  {

    WLog_ERR(TAG, "file name too long (%" PRIuz " characters)", remote_len);

    return FALSE;

  }

  memcpy(descriptor->cFileName, file->remote_name, remote_len * sizeof(WCHAR));

  return TRUE;

}

static FILEDESCRIPTORW* convert_local_file_list_to_filedescriptors(wArrayList* files)

{

  size_t count = 0;

  FILEDESCRIPTORW* descriptors = NULL;

  count = ArrayList_Count(files);

  descriptors = calloc(count, sizeof(FILEDESCRIPTORW));

  if (!descriptors)

    goto error;

  for (size_t i = 0; i < count; i++)

  {

    const struct synthetic_file* file = ArrayList_GetItem(files, i);

    if (!convert_local_file_to_filedescriptor(file, &descriptors[i]))

      goto error;

  }

  return descriptors;

error:

  free(descriptors);

  return NULL;

}

static void* convert_any_uri_list_to_filedescriptors(wClipboard* clipboard,

                                                     WINPR_ATTR_UNUSED UINT32 formatId,

                                                     UINT32* pSize)

{

  FILEDESCRIPTORW* descriptors = NULL;

  WINPR_ASSERT(clipboard);

  WINPR_ASSERT(pSize);

  descriptors = convert_local_file_list_to_filedescriptors(clipboard->localFiles);

  *pSize = 0;

  if (!descriptors)

    return NULL;

  *pSize = (UINT32)ArrayList_Count(clipboard->localFiles) * sizeof(FILEDESCRIPTORW);

  clipboard->fileListSequenceNumber = clipboard->sequenceNumber;

  return descriptors;

}

static void* convert_uri_list_to_filedescriptors(wClipboard* clipboard, UINT32 formatId,

                                                 const void* data, UINT32* pSize)

{

  const UINT32 expected = ClipboardGetFormatId(clipboard, mime_uri_list);

  if (formatId != expected)

    return NULL;

  if (!process_uri_list(clipboard, (const char*)data, *pSize))

    return NULL;

  return convert_any_uri_list_to_filedescriptors(clipboard, formatId, pSize);

}

static BOOL process_files(wClipboard* clipboard, const char* data, UINT32 pSize, const char* prefix)

{

  WINPR_ASSERT(prefix);

  const size_t prefix_len = strlen(prefix);

  WINPR_ASSERT(clipboard);

  ArrayList_Clear(clipboard->localFiles);

  if (!data || (pSize < prefix_len))

    return FALSE;

  if (strncmp(data, prefix, prefix_len) != 0)

    return FALSE;

  data += prefix_len;

  if (pSize < prefix_len)

    return FALSE;

  pSize -= WINPR_ASSERTING_INT_CAST(uint32_t, prefix_len);

  BOOL rc = FALSE;

  char* copy = strndup(data, pSize);

  if (!copy)

    goto fail;

  {

    char* endptr = NULL;

    char* tok = strtok_s(copy, "\n", &endptr);

    while (tok)

    {

      const size_t tok_len = strnlen(tok, pSize);

      if (!process_uri(clipboard, tok, tok_len))

        goto fail;

      if (pSize < tok_len)

        goto fail;

      pSize -= WINPR_ASSERTING_INT_CAST(uint32_t, tok_len);

      tok = strtok_s(NULL, "\n", &endptr);

    }

  }

  rc = TRUE;

fail:

  free(copy);

  return rc;

}

static BOOL process_gnome_copied_files(wClipboard* clipboard, const char* data, UINT32 pSize)

{

  return process_files(clipboard, data, pSize, "copy\n");

}

static BOOL process_mate_copied_files(wClipboard* clipboard, const char* data, UINT32 pSize)

{

  return process_files(clipboard, data, pSize, "copy\n");

}

static void* convert_gnome_copied_files_to_filedescriptors(wClipboard* clipboard, UINT32 formatId,

                                                           const void* data, UINT32* pSize)

{

  const UINT32 expected = ClipboardGetFormatId(clipboard, mime_gnome_copied_files);

  if (formatId != expected)

    return NULL;

  if (!process_gnome_copied_files(clipboard, (const char*)data, *pSize))

    return NULL;

  return convert_any_uri_list_to_filedescriptors(clipboard, formatId, pSize);

}

static void* convert_mate_copied_files_to_filedescriptors(wClipboard* clipboard, UINT32 formatId,

                                                          const void* data, UINT32* pSize)

{

  const UINT32 expected = ClipboardGetFormatId(clipboard, mime_mate_copied_files);

  if (formatId != expected)

    return NULL;

  if (!process_mate_copied_files(clipboard, (const char*)data, *pSize))

    return NULL;

  return convert_any_uri_list_to_filedescriptors(clipboard, formatId, pSize);

}

static size_t count_special_chars(const WCHAR* str)

{

  size_t count = 0;

  const WCHAR* start = str;

  WINPR_ASSERT(str);

  while (*start)

  {

    const WCHAR sharp = '#';

    const WCHAR questionmark = '?';

    const WCHAR star = '*';

    const WCHAR exclamationmark = '!';

    const WCHAR percent = '%';

    if ((*start == sharp) || (*start == questionmark) || (*start == star) ||

        (*start == exclamationmark) || (*start == percent))

    {

      count++;

    }

    start++;

  }

  return count;

}

static const char* stop_at_special_chars(const char* str)

{

  const char* start = str;

  WINPR_ASSERT(str);

  while (*start)

  {

    if (*start == '#' || *start == '?' || *start == '*' || *start == '!' || *start == '%')

    {

      return start;

    }

    start++;

  }

  return NULL;

}

/* The universal converter from filedescriptors to different file lists */

static void* convert_filedescriptors_to_file_list(wClipboard* clipboard, UINT32 formatId,

                                                  const void* data, UINT32* pSize,

                                                  const char* header, const char* lineprefix,

                                                  const char* lineending, BOOL skip_last_lineending)

{

  union

  {

    char c[2];

    WCHAR w;

  } backslash;

  backslash.c[0] = '\\';

  backslash.c[1] = '\0';

  const FILEDESCRIPTORW* descriptors = NULL;

  UINT32 nrDescriptors = 0;

  size_t count = 0;

  size_t alloc = 0;

  size_t pos = 0;

  size_t baseLength = 0;

  char* dst = NULL;

  size_t header_len = strlen(header);

  size_t lineprefix_len = strlen(lineprefix);

  size_t lineending_len = strlen(lineending);

  size_t decoration_len = 0;

  if (!clipboard || !data || !pSize)

    return NULL;

  if (*pSize < sizeof(UINT32))

    return NULL;

  if (clipboard->delegate.basePath)

    baseLength = strnlen(clipboard->delegate.basePath, MAX_PATH);

  if (baseLength < 1)

    return NULL;

  wStream sbuffer = { 0 };

  wStream* s = Stream_StaticConstInit(&sbuffer, data, *pSize);

  if (!Stream_CheckAndLogRequiredLength(TAG, s, 4))

    return NULL;

  Stream_Read_UINT32(s, nrDescriptors);

  count = (*pSize - 4) / sizeof(FILEDESCRIPTORW);

  if ((count < 1) || (count != nrDescriptors))

    return NULL;

  descriptors = Stream_ConstPointer(s);

  if (formatId != ClipboardGetFormatId(clipboard, mime_FileGroupDescriptorW))

    return NULL;

  /* Plus 1 for '/' between basepath and filename*/

  decoration_len = lineprefix_len + lineending_len + baseLength + 1;

  alloc = header_len;

  /* Get total size of file/folder names under first level folder only */

  for (size_t x = 0; x < count; x++)

  {

    const FILEDESCRIPTORW* dsc = &descriptors[x];

    if (_wcschr(dsc->cFileName, backslash.w) == NULL)

    {

      alloc += ARRAYSIZE(dsc->cFileName) *

               8; /* Overallocate, just take the biggest value the result path can have */

                  /* # (1 char) -> %23 (3 chars) , the first char is replaced inplace */

      alloc += count_special_chars(dsc->cFileName) * 2;

      alloc += decoration_len;

    }

  }

  /* Append a prefix file:// and postfix \n for each file */

  /* We need to keep last \n since snprintf is null terminated!!  */

  alloc++;

  dst = calloc(alloc, sizeof(char));

  if (!dst)

    return NULL;

  (void)_snprintf(&dst[0], alloc, "%s", header);

  pos = header_len;

  for (size_t x = 0; x < count; x++)

  {

    const FILEDESCRIPTORW* dsc = &descriptors[x];

    BOOL fail = TRUE;

    if (_wcschr(dsc->cFileName, backslash.w) != NULL)

    {

      continue;

    }

    int rc = -1;

    char curName[520] = { 0 };

    const char* stop_at = NULL;

    const char* previous_at = NULL;

    if (ConvertWCharNToUtf8(dsc->cFileName, ARRAYSIZE(dsc->cFileName), curName,

                            ARRAYSIZE(curName)) < 0)

      goto loop_fail;

    rc = _snprintf(&dst[pos], alloc - pos, "%s%s/", lineprefix, clipboard->delegate.basePath);

    if (rc < 0)

      goto loop_fail;

    pos += (size_t)rc;

    previous_at = curName;

    while ((stop_at = stop_at_special_chars(previous_at)) != NULL)

    {

      const intptr_t diff = stop_at - previous_at;

      if (diff < 0)

        goto loop_fail;

      char* tmp = strndup(previous_at, WINPR_ASSERTING_INT_CAST(size_t, diff));

      if (!tmp)

        goto loop_fail;

      rc = _snprintf(&dst[pos], WINPR_ASSERTING_INT_CAST(size_t, diff + 1), "%s", tmp);

      free(tmp);

      if (rc < 0)

        goto loop_fail;

      pos += (size_t)rc;

      rc = _snprintf(&dst[pos], 4, "%%%x", *stop_at);

      if (rc < 0)

        goto loop_fail;

      pos += (size_t)rc;

      previous_at = stop_at + 1;

    }

    rc = _snprintf(&dst[pos], alloc - pos, "%s%s", previous_at, lineending);

    fail = FALSE;

  loop_fail:

    if ((rc < 0) || fail)

    {

      free(dst);

      return NULL;

    }

    pos += (size_t)rc;

  }

  if (skip_last_lineending)

  {

    const size_t endlen = strlen(lineending);

    if (alloc > endlen)

    {

      const size_t len = strnlen(dst, alloc);

      if (len < endlen)

      {

        free(dst);

        return NULL;

      }

      if (memcmp(&dst[len - endlen], lineending, endlen) == 0)

      {

        memset(&dst[len - endlen], 0, endlen);

        alloc -= endlen;

      }

    }

  }

  alloc = strnlen(dst, alloc) + 1;

  *pSize = (UINT32)alloc;

  clipboard->fileListSequenceNumber = clipboard->sequenceNumber;

  return dst;

}

/* Prepend header of kde dolphin format to file list

 * See:

 *   GTK: https://docs.gtk.org/glib/struct.Uri.html

 *   uri syntax: https://www.rfc-editor.org/rfc/rfc3986#section-3

 *   uri-lists format: https://www.rfc-editor.org/rfc/rfc2483#section-5

 */

static void* convert_filedescriptors_to_uri_list(wClipboard* clipboard, UINT32 formatId,

                                                 const void* data, UINT32* pSize)

{

  return convert_filedescriptors_to_file_list(clipboard, formatId, data, pSize, "", "file://",

                                              "\r\n", FALSE);

}

/* Prepend header of common gnome format to file list*/

static void* convert_filedescriptors_to_gnome_copied_files(wClipboard* clipboard, UINT32 formatId,

                                                           const void* data, UINT32* pSize)

{

  return convert_filedescriptors_to_file_list(clipboard, formatId, data, pSize, "copy\n",

                                              "file://", "\n", TRUE);