Coverage Report

Created: 2026-01-15 06:10

next uncovered line (L), next uncovered region (R), next uncovered branch (B)
/src/giflib-code/gifalloc.c
Line
Count
Source
1
/*****************************************************************************
2
3
 GIF construction tools
4
5
****************************************************************************/
6
// SPDX-License-Identifier: MIT
7
// SPDX-FileCopyrightText: Copyright (C) Eric S. Raymond <esr@thyrsus.com>
8
9
#include <stdio.h>
10
#include <stdlib.h>
11
#include <string.h>
12
13
#include "gif_lib.h"
14
#include "gif_lib_private.h"
15
16
0
#define MAX(x, y) (((x) > (y)) ? (x) : (y))
17
18
/******************************************************************************
19
 Miscellaneous utility functions
20
******************************************************************************/
21
22
/* return smallest bitfield size n will fit in */
23
6.19k
int GifBitSize(int n) {
24
6.19k
  register int i;
25
26
17.4k
  for (i = 1; i <= 8; i++) {
27
17.4k
    if ((1 << i) >= n) {
28
6.19k
      break;
29
6.19k
    }
30
17.4k
  }
31
6.19k
  return (i);
32
6.19k
}
33
34
/******************************************************************************
35
 Color map object functions
36
******************************************************************************/
37
38
/*
39
 * Allocate a color map of given size; initialize with contents of
40
 * ColorMap if that pointer is non-NULL.
41
 */
42
3.09k
ColorMapObject *GifMakeMapObject(int ColorCount, const GifColorType *ColorMap) {
43
3.09k
  ColorMapObject *Object;
44
45
  /*** FIXME: Our ColorCount has to be a power of two.  Is it necessary to
46
   * make the user know that or should we automatically round up instead?
47
   */
48
3.09k
  if (ColorCount != (1 << GifBitSize(ColorCount))) {
49
0
    return ((ColorMapObject *)NULL);
50
0
  }
51
52
3.09k
  Object = (ColorMapObject *)malloc(sizeof(ColorMapObject));
53
3.09k
  if (Object == (ColorMapObject *)NULL) {
54
0
    return ((ColorMapObject *)NULL);
55
0
  }
56
57
3.09k
  Object->Colors =
58
3.09k
      (GifColorType *)calloc(ColorCount, sizeof(GifColorType));
59
3.09k
  if (Object->Colors == (GifColorType *)NULL) {
60
0
    free(Object);
61
0
    return ((ColorMapObject *)NULL);
62
0
  }
63
64
3.09k
  Object->ColorCount = ColorCount;
65
3.09k
  Object->BitsPerPixel = GifBitSize(ColorCount);
66
3.09k
  Object->SortFlag = false;
67
68
3.09k
  if (ColorMap != NULL) {
69
1.44k
    memcpy((char *)Object->Colors, (char *)ColorMap,
70
1.44k
           ColorCount * sizeof(GifColorType));
71
1.44k
  }
72
73
3.09k
  return (Object);
74
3.09k
}
75
76
/*******************************************************************************
77
 Free a color map object
78
*******************************************************************************/
79
3.09k
void GifFreeMapObject(ColorMapObject *Object) {
80
3.09k
  if (Object != NULL) {
81
3.07k
    (void)free(Object->Colors);
82
3.07k
    (void)free(Object);
83
3.07k
  }
84
3.09k
}
85
86
#ifdef DEBUG
87
void DumpColorMap(ColorMapObject *Object, FILE *fp) {
88
  if (Object != NULL) {
89
    int i, j, Len = Object->ColorCount;
90
91
    for (i = 0; i < Len; i += 4) {
92
      for (j = 0; j < 4 && j < Len; j++) {
93
        (void)fprintf(fp, "%3d: %02x %02x %02x   ",
94
                      i + j, Object->Colors[i + j].Red,
95
                      Object->Colors[i + j].Green,
96
                      Object->Colors[i + j].Blue);
97
      }
98
      (void)fprintf(fp, "\n");
99
    }
100
  }
101
}
102
#endif /* DEBUG */
103
104
/*******************************************************************************
105
 Compute the union of two given color maps and return it.  If result can't
106
 fit into 256 colors, NULL is returned, the allocated union otherwise.
107
 ColorIn1 is copied as is to ColorUnion, while colors from ColorIn2 are
108
 copied iff they didn't exist before.  ColorTransIn2 maps the old
109
 ColorIn2 into the ColorUnion color map table./
110
*******************************************************************************/
111
ColorMapObject *GifUnionColorMap(const ColorMapObject *ColorIn1,
112
                                 const ColorMapObject *ColorIn2,
113
0
                                 GifPixelType ColorTransIn2[]) {
114
0
  int i, j, CrntSlot, RoundUpTo, NewGifBitSize;
115
0
  ColorMapObject *ColorUnion;
116
117
  /*
118
   * We don't worry about duplicates within either color map; if
119
   * the caller wants to resolve those, he can perform unions
120
   * with an empty color map.
121
   */
122
123
  /* Allocate table which will hold the result for sure. */
124
0
  ColorUnion = GifMakeMapObject(
125
0
      MAX(ColorIn1->ColorCount, ColorIn2->ColorCount) * 2, NULL);
126
127
0
  if (ColorUnion == NULL) {
128
0
    return (NULL);
129
0
  }
130
131
  /*
132
   * Copy ColorIn1 to ColorUnion.
133
   */
134
0
  for (i = 0; i < ColorIn1->ColorCount; i++) {
135
0
    ColorUnion->Colors[i] = ColorIn1->Colors[i];
136
0
  }
137
0
  CrntSlot = ColorIn1->ColorCount;
138
139
  /*
140
   * Potentially obnoxious hack:
141
   *
142
   * Back CrntSlot down past all contiguous {0, 0, 0} slots at the end
143
   * of table 1.  This is very useful if your display is limited to
144
   * 16 colors.
145
   */
146
0
  while (ColorIn1->Colors[CrntSlot - 1].Red == 0 &&
147
0
         ColorIn1->Colors[CrntSlot - 1].Green == 0 &&
148
0
         ColorIn1->Colors[CrntSlot - 1].Blue == 0) {
149
0
    CrntSlot--;
150
0
  }
151
152
  /* Copy ColorIn2 to ColorUnion (use old colors if they exist): */
153
0
  for (i = 0; i < ColorIn2->ColorCount && CrntSlot <= 256; i++) {
154
    /* Let's see if this color already exists: */
155
0
    for (j = 0; j < ColorIn1->ColorCount; j++) {
156
0
      if (memcmp(&ColorIn1->Colors[j], &ColorIn2->Colors[i],
157
0
                 sizeof(GifColorType)) == 0) {
158
0
        break;
159
0
      }
160
0
    }
161
162
0
    if (j < ColorIn1->ColorCount) {
163
0
      ColorTransIn2[i] = j; /* color exists in Color1 */
164
0
    } else {
165
      /* Color is new - copy it to a new slot: */
166
0
      ColorUnion->Colors[CrntSlot] = ColorIn2->Colors[i];
167
0
      ColorTransIn2[i] = CrntSlot++;
168
0
    }
169
0
  }
170
171
0
  if (CrntSlot > 256) {
172
0
    GifFreeMapObject(ColorUnion);
173
0
    return ((ColorMapObject *)NULL);
174
0
  }
175
176
0
  NewGifBitSize = GifBitSize(CrntSlot);
177
0
  RoundUpTo = (1 << NewGifBitSize);
178
179
0
  if (RoundUpTo != ColorUnion->ColorCount) {
180
0
    register GifColorType *Map = ColorUnion->Colors;
181
182
    /*
183
     * Zero out slots up to next power of 2.
184
     * We know these slots exist because of the way ColorUnion's
185
     * start dimension was computed.
186
     */
187
0
    for (j = CrntSlot; j < RoundUpTo; j++) {
188
0
      Map[j].Red = Map[j].Green = Map[j].Blue = 0;
189
0
    }
190
191
    /* perhaps we can shrink the map? */
192
0
    if (RoundUpTo < ColorUnion->ColorCount) {
193
0
      GifColorType *new_map = (GifColorType *)reallocarray(
194
0
          Map, RoundUpTo, sizeof(GifColorType));
195
0
      if (new_map == NULL) {
196
0
        GifFreeMapObject(ColorUnion);
197
0
        return ((ColorMapObject *)NULL);
198
0
      }
199
0
      ColorUnion->Colors = new_map;
200
0
    }
201
0
  }
202
203
0
  ColorUnion->ColorCount = RoundUpTo;
204
0
  ColorUnion->BitsPerPixel = NewGifBitSize;
205
206
0
  return (ColorUnion);
207
0
}
208
209
/*******************************************************************************
210
 Apply a given color translation to the raster bits of an image
211
*******************************************************************************/
212
0
void GifApplyTranslation(SavedImage *Image, const GifPixelType Translation[]) {
213
0
  register int i;
214
0
  register int RasterSize =
215
0
      Image->ImageDesc.Height * Image->ImageDesc.Width;
216
217
0
  for (i = 0; i < RasterSize; i++) {
218
0
    Image->RasterBits[i] = Translation[Image->RasterBits[i]];
219
0
  }
220
0
}
221
222
/******************************************************************************
223
 Extension record functions
224
******************************************************************************/
225
int GifAddExtensionBlock(int *ExtensionBlockCount,
226
                         ExtensionBlock **ExtensionBlocks, int Function,
227
103k
                         unsigned int Len, unsigned char ExtData[]) {
228
103k
  ExtensionBlock *ep;
229
230
103k
  if (*ExtensionBlocks == NULL) {
231
5.78k
    *ExtensionBlocks =
232
5.78k
        (ExtensionBlock *)malloc(sizeof(ExtensionBlock));
233
97.6k
  } else {
234
97.6k
    ExtensionBlock *ep_new = (ExtensionBlock *)reallocarray(
235
97.6k
        *ExtensionBlocks, (*ExtensionBlockCount + 1),
236
97.6k
        sizeof(ExtensionBlock));
237
97.6k
    if (ep_new == NULL) {
238
0
      return (GIF_ERROR);
239
0
    }
240
97.6k
    *ExtensionBlocks = ep_new;
241
97.6k
  }
242
243
103k
  if (*ExtensionBlocks == NULL) {
244
0
    return (GIF_ERROR);
245
0
  }
246
247
103k
  ep = &(*ExtensionBlocks)[(*ExtensionBlockCount)++];
248
249
103k
  ep->Function = Function;
250
103k
  ep->ByteCount = Len;
251
103k
  ep->Bytes = (GifByteType *)malloc(ep->ByteCount);
252
103k
  if (ep->Bytes == NULL) {
253
0
    return (GIF_ERROR);
254
0
  }
255
256
103k
  if (ExtData != NULL) {
257
103k
    memcpy(ep->Bytes, ExtData, Len);
258
103k
  }
259
260
103k
  return (GIF_OK);
261
103k
}
262
263
void GifFreeExtensions(int *ExtensionBlockCount,
264
81.2k
                       ExtensionBlock **ExtensionBlocks) {
265
81.2k
  ExtensionBlock *ep;
266
267
81.2k
  if (*ExtensionBlocks == NULL) {
268
75.5k
    return;
269
75.5k
  }
270
271
5.78k
  for (ep = *ExtensionBlocks;
272
109k
       ep < (*ExtensionBlocks + *ExtensionBlockCount); ep++) {
273
103k
    (void)free((char *)ep->Bytes);
274
103k
  }
275
5.78k
  (void)free((char *)*ExtensionBlocks);
276
5.78k
  *ExtensionBlocks = NULL;
277
5.78k
  *ExtensionBlockCount = 0;
278
5.78k
}
279
280
/******************************************************************************
281
   Image block allocation functions
282
******************************************************************************/
283
284
/* Private Function:
285
 * Frees the last image in the GifFile->SavedImages array
286
 */
287
0
void FreeLastSavedImage(GifFileType *GifFile) {
288
0
  SavedImage *sp;
289
290
0
  if ((GifFile == NULL) || (GifFile->SavedImages == NULL)) {
291
0
    return;
292
0
  }
293
294
  /* Remove one SavedImage from the GifFile */
295
0
  GifFile->ImageCount--;
296
0
  sp = &GifFile->SavedImages[GifFile->ImageCount];
297
298
  /* Deallocate its Colormap */
299
0
  if (sp->ImageDesc.ColorMap != NULL) {
300
0
    GifFreeMapObject(sp->ImageDesc.ColorMap);
301
0
    sp->ImageDesc.ColorMap = NULL;
302
0
  }
303
304
  /* Deallocate the image data */
305
0
  if (sp->RasterBits != NULL) {
306
0
    free((char *)sp->RasterBits);
307
0
  }
308
309
  /* Deallocate any extensions */
310
0
  GifFreeExtensions(&sp->ExtensionBlockCount, &sp->ExtensionBlocks);
311
312
  /*** FIXME: We could realloc the GifFile->SavedImages structure but is
313
   * there a point to it? Saves some memory but we'd have to do it every
314
   * time.  If this is used in GifFreeSavedImages then it would be
315
   * inefficient (The whole array is going to be deallocated.)  If we just
316
   * use it when we want to free the last Image it's convenient to do it
317
   * here.
318
   */
319
0
}
320
321
/*
322
 * Append an image block to the SavedImages array
323
 */
324
SavedImage *GifMakeSavedImage(GifFileType *GifFile,
325
0
                              const SavedImage *CopyFrom) {
326
  // cppcheck-suppress ctunullpointer
327
0
  if (GifFile->SavedImages == NULL) {
328
0
    GifFile->SavedImages = (SavedImage *)malloc(sizeof(SavedImage));
329
0
  } else {
330
0
    SavedImage *newSavedImages = (SavedImage *)reallocarray(
331
0
        GifFile->SavedImages, (GifFile->ImageCount + 1),
332
0
        sizeof(SavedImage));
333
0
    if (newSavedImages == NULL) {
334
0
      return ((SavedImage *)NULL);
335
0
    }
336
0
    GifFile->SavedImages = newSavedImages;
337
0
  }
338
0
  if (GifFile->SavedImages == NULL) {
339
0
    return ((SavedImage *)NULL);
340
0
  } else {
341
0
    SavedImage *sp = &GifFile->SavedImages[GifFile->ImageCount++];
342
343
0
    if (CopyFrom != NULL) {
344
0
      memcpy((char *)sp, CopyFrom, sizeof(SavedImage));
345
346
      /*
347
       * Make our own allocated copies of the heap fields in
348
       * the copied record.  This guards against potential
349
       * aliasing problems.
350
       */
351
352
      /* first, the local color map */
353
0
      if (CopyFrom->ImageDesc.ColorMap != NULL) {
354
0
        sp->ImageDesc.ColorMap = GifMakeMapObject(
355
0
            CopyFrom->ImageDesc.ColorMap->ColorCount,
356
0
            CopyFrom->ImageDesc.ColorMap->Colors);
357
0
        if (sp->ImageDesc.ColorMap == NULL) {
358
0
          FreeLastSavedImage(GifFile);
359
0
          return (SavedImage *)(NULL);
360
0
        }
361
0
      }
362
363
      /* next, the raster */
364
0
      sp->RasterBits = (unsigned char *)reallocarray(
365
0
          NULL,
366
0
          (CopyFrom->ImageDesc.Height *
367
0
           CopyFrom->ImageDesc.Width),
368
0
          sizeof(GifPixelType));
369
0
      if (sp->RasterBits == NULL) {
370
0
        FreeLastSavedImage(GifFile);
371
0
        return (SavedImage *)(NULL);
372
0
      }
373
0
      memcpy(sp->RasterBits, CopyFrom->RasterBits,
374
0
             sizeof(GifPixelType) *
375
0
                 CopyFrom->ImageDesc.Height *
376
0
                 CopyFrom->ImageDesc.Width);
377
378
      /* finally, the extension blocks */
379
0
      if (CopyFrom->ExtensionBlocks != NULL) {
380
0
        sp->ExtensionBlocks =
381
0
            (ExtensionBlock *)reallocarray(
382
0
                NULL, CopyFrom->ExtensionBlockCount,
383
0
                sizeof(ExtensionBlock));
384
0
        if (sp->ExtensionBlocks == NULL) {
385
0
          FreeLastSavedImage(GifFile);
386
0
          return (SavedImage *)(NULL);
387
0
        }
388
0
        memcpy(sp->ExtensionBlocks,
389
0
               CopyFrom->ExtensionBlocks,
390
0
               sizeof(ExtensionBlock) *
391
0
                   CopyFrom->ExtensionBlockCount);
392
0
      }
393
0
    } else {
394
0
      memset((char *)sp, '\0', sizeof(SavedImage));
395
0
    }
396
397
0
    return (sp);
398
0
  }
399
0
}
400
401
1.30k
void GifFreeSavedImages(GifFileType *GifFile) {
402
1.30k
  SavedImage *sp;
403
404
1.30k
  if ((GifFile == NULL) || (GifFile->SavedImages == NULL)) {
405
0
    return;
406
0
  }
407
1.30k
  for (sp = GifFile->SavedImages;
408
80.7k
       sp < GifFile->SavedImages + GifFile->ImageCount; sp++) {
409
79.4k
    if (sp->ImageDesc.ColorMap != NULL) {
410
1.07k
      GifFreeMapObject(sp->ImageDesc.ColorMap);
411
1.07k
      sp->ImageDesc.ColorMap = NULL;
412
1.07k
    }
413
414
79.4k
    if (sp->RasterBits != NULL) {
415
79.4k
      free((char *)sp->RasterBits);
416
79.4k
    }
417
418
79.4k
    GifFreeExtensions(&sp->ExtensionBlockCount,
419
79.4k
                      &sp->ExtensionBlocks);
420
79.4k
  }
421
1.30k
  free((char *)GifFile->SavedImages);
422
  GifFile->SavedImages = NULL;
423
1.30k
}
424
425
/* end */