Update libwebp to 0.5.2

3 files changed, 21 insertions, 5 deletions

diff --git a/thirdparty/libwebp/utils/rescaler.c b/thirdparty/libwebp/utils/rescaler.c
index 00c9300bfb..d2278a52ff 100644
--- a/thirdparty/libwebp/utils/rescaler.c
+++ b/thirdparty/libwebp/utils/rescaler.c
@@ -48,11 +48,15 @@ void WebPRescalerInit(WebPRescaler* const wrk, int src_width, int src_height,
   wrk->y_sub = wrk->y_expand ? y_sub - 1 : y_sub;
   wrk->y_accum = wrk->y_expand ? wrk->y_sub : wrk->y_add;
   if (!wrk->y_expand) {
-    // this is WEBP_RESCALER_FRAC(dst_height, x_add * y_add) without the cast.
+    // This is WEBP_RESCALER_FRAC(dst_height, x_add * y_add) without the cast.
+    // Its value is <= WEBP_RESCALER_ONE, because dst_height <= wrk->y_add, and
+    // wrk->x_add >= 1;
     const uint64_t ratio =
         (uint64_t)dst_height * WEBP_RESCALER_ONE / (wrk->x_add * wrk->y_add);
     if (ratio != (uint32_t)ratio) {
-      // We can't represent the ratio with the current fixed-point precision.
+      // When ratio == WEBP_RESCALER_ONE, we can't represent the ratio with the
+      // current fixed-point precision. This happens when src_height ==
+      // wrk->y_add (which == src_height), and wrk->x_add == 1.
       // => We special-case fxy_scale = 0, in WebPRescalerExportRow().
       wrk->fxy_scale = 0;
     } else {
diff --git a/thirdparty/libwebp/utils/utils.c b/thirdparty/libwebp/utils/utils.c
index 2602ca3c9f..82dbf8d5e5 100644
--- a/thirdparty/libwebp/utils/utils.c
+++ b/thirdparty/libwebp/utils/utils.c
@@ -175,8 +175,12 @@ static int CheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
   }
 #endif
 #if defined(MALLOC_LIMIT)
-  if (mem_limit > 0 && total_mem + total_size >= mem_limit) {
-    return 0;   // fake fail!
+  if (mem_limit > 0) {
+    const uint64_t new_total_mem = (uint64_t)total_mem + total_size;
+    if (new_total_mem != (size_t)new_total_mem ||
+        new_total_mem > mem_limit) {
+      return 0;   // fake fail!
+    }
   }
 #endif
 
diff --git a/thirdparty/libwebp/utils/utils.h b/thirdparty/libwebp/utils/utils.h
index e0a81126df..3a5d4e6a78 100644
--- a/thirdparty/libwebp/utils/utils.h
+++ b/thirdparty/libwebp/utils/utils.h
@@ -20,6 +20,7 @@
 #endif
 
 #include <assert.h>
+#include <limits.h>
 
 #include "../dsp/dsp.h"
 #include "../webp/types.h"
@@ -32,7 +33,14 @@ extern "C" {
 // Memory allocation
 
 // This is the maximum memory amount that libwebp will ever try to allocate.
-#define WEBP_MAX_ALLOCABLE_MEMORY (1ULL << 40)
+#ifndef WEBP_MAX_ALLOCABLE_MEMORY
+#if SIZE_MAX > (1ULL << 34)
+#define WEBP_MAX_ALLOCABLE_MEMORY (1ULL << 34)
+#else
+// For 32-bit targets keep this below INT_MAX to avoid valgrind warnings.
+#define WEBP_MAX_ALLOCABLE_MEMORY ((1ULL << 31) - (1 << 16))
+#endif
+#endif  // WEBP_MAX_ALLOCABLE_MEMORY
 
 // size-checking safe malloc/calloc: verify that the requested size is not too
 // large, or return NULL. You don't need to call these for constructs like