Merge "fix some warnings from static analysis"

src/demux/demux.c

@@ -425,6 +425,7 @@ static ParseStatus ParseSingleImage(WebPDemuxer* const dmux) {
   MemBuffer* const mem = &dmux->mem_;
   Frame* frame;
   ParseStatus status;
+  int image_added = 0;
 
   if (dmux->frames_ != NULL) return PARSE_ERROR;
   if (SizeIsInvalid(mem, min_size)) return PARSE_ERROR;
@@ -453,12 +454,15 @@ static ParseStatus ParseSingleImage(WebPDemuxer* const dmux) {
       dmux->canvas_height_ = frame->height_;
       dmux->feature_flags_ |= frame->has_alpha_ ? ALPHA_FLAG : 0;
     }
-    AddFrame(dmux, frame);
-    dmux->num_frames_ = 1;
-  } else {
-    free(frame);
+    if (!AddFrame(dmux, frame)) {
+      status = PARSE_ERROR;  // last frame was left incomplete
+    } else {
+      image_added = 1;
+      dmux->num_frames_ = 1;
+    }
   }
 
+  if (!image_added) free(frame);
   return status;
 }
 

src/enc/analysis.c

@@ -153,6 +153,8 @@ static void AssignSegments(VP8Encoder* const enc,
   // 'int' type is ok for histo, and won't overflow
   int accum[NUM_MB_SEGMENTS], dist_accum[NUM_MB_SEGMENTS];
 
+  assert(nb >= 1);
+
   // bracket the input
   for (n = 0; n <= MAX_ALPHA && alphas[n] == 0; ++n) {}
   min_a = n;
@@ -161,8 +163,9 @@ static void AssignSegments(VP8Encoder* const enc,
   range_a = max_a - min_a;
 
   // Spread initial centers evenly
-  for (n = 1, k = 0; n < 2 * nb; n += 2) {
-    centers[k++] = min_a + (n * range_a) / (2 * nb);
+  for (k = 0, n = 1; k < nb; ++k, n += 2) {
+    assert(n < 2 * nb);
+    centers[k] = min_a + (n * range_a) / (2 * nb);
   }
 
   for (k = 0; k < MAX_ITERS_K_MEANS; ++k) {     // few iters are enough
@@ -177,7 +180,7 @@ static void AssignSegments(VP8Encoder* const enc,
     n = 0;    // track the nearest center for current 'a'
     for (a = min_a; a <= max_a; ++a) {
       if (alphas[a]) {
-        while (n < nb - 1 && abs(a - centers[n + 1]) < abs(a - centers[n])) {
+        while (n + 1 < nb && abs(a - centers[n + 1]) < abs(a - centers[n])) {
           n++;
         }
         map[a] = n;

src/enc/frame.c

@@ -976,6 +976,7 @@ int VP8EncTokenLoop(VP8Encoder* const enc) {
   assert(enc->use_tokens_);
   assert(proba->use_skip_proba_ == 0);
   assert(rd_opt >= RD_OPT_BASIC);   // otherwise, token-buffer won't be useful
+  assert(num_pass_left > 0);
 
   while (ok && num_pass_left-- > 0) {
     const int is_last_pass = (fabs(stats.dq) <= DQ_LIMIT) ||

src/enc/picture.c

@@ -123,6 +123,7 @@ int WebPPictureAlloc(WebPPicture* picture) {
         picture->v0 = mem;
         mem += uv0_size;
       }
+      (void)mem;  // makes the static analyzer happy
     } else {
       void* memory;
       const uint64_t argb_size = (uint64_t)width * height;
@@ -698,6 +699,7 @@ static int ImportYUVAFromRGBA(const uint8_t* const r_ptr,
 
   if (has_alpha) {
     assert(step >= 4);
+    assert(picture->a != NULL);
     for (y = 0; y < height; ++y) {
       for (x = 0; x < width; ++x) {
         picture->a[x + y * picture->a_stride] =

src/mux/muxedit.c

@@ -403,10 +403,12 @@ static WebPMuxError GetImageInfo(const WebPMuxImage* const wpi,
                                  int* const duration,
                                  int* const width, int* const height) {
   const WebPChunk* const frame_frgm_chunk = wpi->header_;
+  WebPMuxError err;
+  assert(wpi != NULL);
+  assert(frame_frgm_chunk != NULL);
 
   // Get offsets and duration from ANMF/FRGM chunk.
-  const WebPMuxError err =
-      GetFrameFragmentInfo(frame_frgm_chunk, x_offset, y_offset, duration);
+  err = GetFrameFragmentInfo(frame_frgm_chunk, x_offset, y_offset, duration);
   if (err != WEBP_MUX_OK) return err;
 
   // Get width and height from VP8/VP8L chunk.
@@ -426,10 +428,12 @@ static WebPMuxError GetImageCanvasWidthHeight(
   assert(wpi != NULL);
   assert(wpi->img_ != NULL);
 
-  if (wpi->next_) {
+  if (wpi->next_ != NULL) {
     int max_x = 0;
     int max_y = 0;
     int64_t image_area = 0;
+    // if we have a chain of wpi's, header_ is necessarily set
+    assert(wpi->header_ != NULL);
     // Aggregate the bounding box for animation frames & fragmented images.
     for (; wpi != NULL; wpi = wpi->next_) {
       int x_offset = 0, y_offset = 0, duration = 0, w = 0, h = 0;

src/utils/bit_writer.c

@@ -43,7 +43,10 @@ static int BitWriterResize(VP8BitWriter* const bw, size_t extra_size) {
     bw->error_ = 1;
     return 0;
   }
-  memcpy(new_buf, bw->buf_, bw->pos_);
+  if (bw->pos_ > 0) {
+    assert(bw->buf_ != NULL);
+    memcpy(new_buf, bw->buf_, bw->pos_);
+  }
   free(bw->buf_);
   bw->buf_ = new_buf;
   bw->max_pos_ = new_size;