add malloc failure test for cgif_raw API

src/cgif_raw.c

@@ -308,6 +308,7 @@ static int LZW_GenerateStream(LZWResult* pResult, const uint32_t numPixel, const
   if(pContext == NULL) {
     return CGIF_EALLOC;
   }
+  memset(pContext, 0, sizeof(LZWGenState));
   pContext->pTreeInit  = malloc((initDictLen * sizeof(uint16_t)) * initDictLen);
   if(pContext->pTreeInit == NULL) {
     r = CGIF_EALLOC;

tests/ealloc_raw.c

@@ -0,0 +1,97 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "cgif_raw.h"
+
+#define WIDTH  2
+#define HEIGHT 2
+
+/* malloc failure injection */
+static int fail_after   = 0;
+static int malloc_count = 0;
+
+static void* cgif_test_malloc(size_t size) {
+  if(fail_after > 0) {
+    ++malloc_count;
+    if(malloc_count == fail_after) {
+      return NULL;
+    }
+  }
+  return malloc(size);
+}
+
+/* redirect malloc calls inside cgif_raw.c to our wrapper */
+#define malloc(s) cgif_test_malloc(s)
+#include "../src/cgif_raw.c"
+#undef malloc
+
+/* no-op write callback */
+static int writeFn(void* pContext, const uint8_t* pData, const size_t numBytes) {
+  (void)pContext;
+  (void)pData;
+  (void)numBytes;
+  return 0;
+}
+
+int main(void) {
+  CGIFRaw*            pGIF;
+  CGIFRaw_Config      gConfig;
+  CGIFRaw_FrameConfig fConfig;
+  cgif_result         r;
+  uint8_t aPalette[] = {
+    0x00, 0x00, 0x00, // black
+    0xFF, 0xFF, 0xFF, // white
+  };
+  uint8_t aImageData[WIDTH * HEIGHT];
+  memset(aImageData, 0, sizeof(aImageData));
+
+  for(int n = 1; ; ++n) {
+    memset(&gConfig, 0, sizeof(gConfig));
+    memset(&fConfig, 0, sizeof(fConfig));
+    gConfig.pWriteFn = writeFn;
+    gConfig.width    = WIDTH;
+    gConfig.height   = HEIGHT;
+    gConfig.pGCT     = aPalette;
+    gConfig.sizeGCT  = 2;
+
+    fConfig.pImageData = aImageData;
+    fConfig.width      = WIDTH;
+    fConfig.height     = HEIGHT;
+
+    fail_after  = n;
+    malloc_count = 0;
+
+    pGIF = cgif_raw_newgif(&gConfig);
+    if(pGIF == NULL) {
+      if(malloc_count >= n) {
+        continue; // expected: our injected malloc failure
+      }
+      fputs("unexpected NULL from cgif_raw_newgif\n", stderr);
+      return 1;
+    }
+
+    r = cgif_raw_addframe(pGIF, &fConfig);
+    if(r != CGIF_OK) {
+      if(r == CGIF_EALLOC && malloc_count >= n) {
+        cgif_raw_close(pGIF);
+        continue; // expected: our injected malloc failure
+      }
+      fprintf(stderr, "unexpected error from cgif_raw_addframe: %d\n", r);
+      return 1;
+    }
+
+    r = cgif_raw_close(pGIF);
+    if(malloc_count < n) {
+      // all mallocs succeeded without hitting our failure point -- done
+      if(r != CGIF_OK) {
+        fprintf(stderr, "unexpected error from cgif_raw_close: %d\n", r);
+        return 1;
+      }
+      break;
+    }
+  }
+
+  return 0;
+}

tests/meson.build

@@ -75,6 +75,14 @@ foreach t : tests_index + tests_rgb
   test(name, test_exe, priority : 0)
 endforeach
 
+# malloc failure tests (compile source directly to intercept malloc)
+test_ealloc_raw_exe = executable(
+  'test_ealloc_raw',
+  'ealloc_raw.c',
+  include_directories : ['../inc/'],
+)
+test('ealloc_raw', test_ealloc_raw_exe, priority : 0)
+
 sha256sumc = find_program('scripts/sha256sum.py')
 # get the ordering right:
 # md5sum check on output GIFs should be run once all of the above tests are done.