commit ec32eb3eb78bdc90fb09b6889b668e54c9735d21
author Nigel Tao <nigeltao@golang.org> Fri Jun 18 22:37:29 2021 +1000
committer Nigel Tao <nigeltao@golang.org> Fri Jun 18 22:37:29 2021 +1000
tree 79cb26d11ba674fe33e7c4afc5d534fde479e009
parent a51867dc63f7a6839411754f5d66800a27706b3e

Add fuzz/c/std/gif_fuzzer.c quirks

fuzz/c/std/gif_fuzzer.c

diff --git a/fuzz/c/std/gif_fuzzer.c b/fuzz/c/std/gif_fuzzer.c
index cf58b33..2da0d1b 100644
--- a/fuzz/c/std/gif_fuzzer.c
+++ b/fuzz/c/std/gif_fuzzer.c
@@ -61,6 +61,27 @@
 #include "../fuzzlib/fuzzlib.c"
 #include "../fuzzlib/fuzzlib_image_decoder.c"
 
+void set_quirks(wuffs_gif__decoder* dec, uint64_t hash_55_bits) {
+  uint32_t quirks[] = {
+      WUFFS_GIF__QUIRK_DELAY_NUM_DECODED_FRAMES,
+      WUFFS_GIF__QUIRK_FIRST_FRAME_LOCAL_PALETTE_MEANS_BLACK_BACKGROUND,
+      WUFFS_GIF__QUIRK_HONOR_BACKGROUND_COLOR,
+      WUFFS_GIF__QUIRK_IGNORE_TOO_MUCH_PIXEL_DATA,
+      WUFFS_GIF__QUIRK_IMAGE_BOUNDS_ARE_STRICT,
+      WUFFS_GIF__QUIRK_REJECT_EMPTY_FRAME,
+      WUFFS_GIF__QUIRK_REJECT_EMPTY_PALETTE,
+      0,
+  };
+
+  uint32_t i;
+  for (i = 0; quirks[i]; i++) {
+    uint64_t bit = 1 << (i % 55);
+    if (hash_55_bits & bit) {
+      wuffs_gif__decoder__set_quirk_enabled(dec, quirks[i], true);
+    }
+  }
+}
+
 const char*  //
 fuzz(wuffs_base__io_buffer* src, uint64_t hash) {
   wuffs_gif__decoder dec;
@@ -68,10 +89,13 @@
       &dec, sizeof dec, WUFFS_VERSION,
       (hash & 1) ? WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED : 0);
   hash >>= 1;
+  uint64_t hash_8_bits = hash & 0xFF;
+  uint64_t hash_55_bits = hash >> 8;
   if (!wuffs_base__status__is_ok(&status)) {
     return wuffs_base__status__message(&status);
   }
+  set_quirks(&dec, hash_55_bits);
   return fuzz_image_decoder(
-      src, hash,
+      src, hash_8_bits,
       wuffs_gif__decoder__upcast_as__wuffs_base__image_decoder(&dec));
 }