windowscodecs: Don't reorder gif extension blocks in GetReaderByIndex.

dlls/windowscodecs/gifformat.c

@@ -947,7 +947,10 @@ static HRESULT WINAPI GifFrameDecode_Block_GetReaderByIndex(IWICMetadataBlockRea
     UINT index, IWICMetadataReader **reader)
 {
     GifFrameDecode *This = frame_from_IWICMetadataBlockReader(iface);
-    int i, gce_index = -1, gce_skipped = 0;
+    class_constructor constructor;
+    ExtensionBlock *ext;
+    const void *data;
+    int data_size;
 
     TRACE("(%p,%u,%p)\n", iface, index, reader);
 
@@ -959,40 +962,27 @@ static HRESULT WINAPI GifFrameDecode_Block_GetReaderByIndex(IWICMetadataBlockRea
     if (index >= This->frame->Extensions.ExtensionBlockCount + 1)
         return E_INVALIDARG;
 
-    for (i = 0; i < This->frame->Extensions.ExtensionBlockCount; i++)
+    ext = This->frame->Extensions.ExtensionBlocks + index - 1;
+    if (ext->Function == GRAPHICS_EXT_FUNC_CODE)
     {
-        class_constructor constructor;
-        const void *data;
-        int data_size;
-
-        if (index != i + 1 - gce_skipped) continue;
-
-        if (This->frame->Extensions.ExtensionBlocks[i].Function == GRAPHICS_EXT_FUNC_CODE)
-        {
-            gce_index = i;
-            gce_skipped = 1;
-            continue;
+        constructor = GCEReader_CreateInstance;
+        data = ext->Bytes + 3;
+        data_size = ext->ByteCount - 4;
     }
-        else if (This->frame->Extensions.ExtensionBlocks[i].Function == COMMENT_EXT_FUNC_CODE)
+    else if (ext->Function == COMMENT_EXT_FUNC_CODE)
     {
         constructor = GifCommentReader_CreateInstance;
-            data = This->frame->Extensions.ExtensionBlocks[i].Bytes;
-            data_size = This->frame->Extensions.ExtensionBlocks[i].ByteCount;
+        data = ext->Bytes;
+        data_size = ext->ByteCount;
     }
     else
     {
         constructor = UnknownMetadataReader_CreateInstance;
-            data = This->frame->Extensions.ExtensionBlocks[i].Bytes;
-            data_size = This->frame->Extensions.ExtensionBlocks[i].ByteCount;
-        }
-        return create_metadata_reader(data, data_size, constructor, reader);
+        data = ext->Bytes;
+        data_size = ext->ByteCount;
     }
 
-    if (gce_index == -1) return E_INVALIDARG;
-
-    return create_metadata_reader(This->frame->Extensions.ExtensionBlocks[gce_index].Bytes + 3,
-                                  This->frame->Extensions.ExtensionBlocks[gce_index].ByteCount - 4,
-                                  GCEReader_CreateInstance, reader);
+    return create_metadata_reader(data, data_size, constructor, reader);
 }
 
 static HRESULT WINAPI GifFrameDecode_Block_GetEnumerator(IWICMetadataBlockReader *iface,

dlls/windowscodecs/tests/metadata.c

@@ -188,10 +188,10 @@ static const char animatedgif[] = {
 0x00,0x00,0x00,0x00,0x01,0x00,0x01,0x00,0x81,
 0xDE,0xDE,0xDE,0x00,0x00,0x00,
 0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x02,0x4C,0x01,0x00,
+0x21,0xF9,0x04,0x01,0x0A,0x00,0x01,0x00,
 0x21,0xFE,0x08,'i','m','a','g','e',' ','#','1',0x00,
 0x21,0x01,0x0C,'p','l','a','i','n','t','e','x','t',' ','#','1',0x00,
-0x21,0xF9,0x04,0x01,0x0A,0x00,0x01,0x00,0x2C,
-0x00,0x00,0x00,0x00,0x01,0x00,0x01,0x00,0x81,
+0x2C,0x00,0x00,0x00,0x00,0x01,0x00,0x01,0x00,0x81,
 0x4D,0x4D,0x4D,0x00,0x00,0x00,
 0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x02,0x44,0x01,0x00,
 0x21,0xFE,0x08,'i','m','a','g','e',' ','#','2',0x00,
@@ -1517,15 +1517,14 @@ static void test_metadata_gif(void)
         {
             hr = IWICMetadataReader_GetMetadataFormat(reader, &format);
             ok(hr == S_OK, "GetMetadataFormat failed, hr=%#lx\n", hr);
-            ok(IsEqualGUID(&format, &GUID_MetadataFormatGifComment), /* Comment Extension */
+            ok(IsEqualGUID(&format, &GUID_MetadataFormatGCE), /* Graphic Control Extension */
                "wrong metadata format %s\n", wine_dbgstr_guid(&format));
 
             hr = IWICMetadataReader_GetCount(reader, &count);
             ok(hr == S_OK, "GetCount error %#lx\n", hr);
-            ok(count == ARRAY_SIZE(animated_gif_comment_2), "unexpected count %u\n", count);
+            ok(count == ARRAY_SIZE(animated_gif_GCE), "unexpected count %u\n", count);
 
-            if (count == 1)
-            compare_metadata(reader, animated_gif_comment_2, count);
+            compare_metadata(reader, animated_gif_GCE, count);
 
             IWICMetadataReader_Release(reader);
         }
@@ -1537,14 +1536,15 @@ static void test_metadata_gif(void)
         {
             hr = IWICMetadataReader_GetMetadataFormat(reader, &format);
             ok(hr == S_OK, "GetMetadataFormat failed, hr=%#lx\n", hr);
-            ok(IsEqualGUID(&format, &GUID_MetadataFormatUnknown),
+            ok(IsEqualGUID(&format, &GUID_MetadataFormatGifComment), /* Comment Extension */
                 "wrong metadata format %s\n", wine_dbgstr_guid(&format));
 
             hr = IWICMetadataReader_GetCount(reader, &count);
             ok(hr == S_OK, "GetCount error %#lx\n", hr);
-            ok(count == ARRAY_SIZE(animated_gif_plain_2), "unexpected count %u\n", count);
+            ok(count == ARRAY_SIZE(animated_gif_comment_2), "unexpected count %u\n", count);
 
-            compare_metadata(reader, animated_gif_plain_2, count);
+            if (count == 1)
+            compare_metadata(reader, animated_gif_comment_2, count);
 
             IWICMetadataReader_Release(reader);
         }
@@ -1556,14 +1556,14 @@ static void test_metadata_gif(void)
         {
             hr = IWICMetadataReader_GetMetadataFormat(reader, &format);
             ok(hr == S_OK, "GetMetadataFormat failed, hr=%#lx\n", hr);
-            ok(IsEqualGUID(&format, &GUID_MetadataFormatGCE), /* Graphic Control Extension */
+            ok(IsEqualGUID(&format, &GUID_MetadataFormatUnknown),
                "wrong metadata format %s\n", wine_dbgstr_guid(&format));
 
             hr = IWICMetadataReader_GetCount(reader, &count);
             ok(hr == S_OK, "GetCount error %#lx\n", hr);
-            ok(count == ARRAY_SIZE(animated_gif_GCE), "unexpected count %u\n", count);
+            ok(count == ARRAY_SIZE(animated_gif_plain_2), "unexpected count %u\n", count);
 
-            compare_metadata(reader, animated_gif_GCE, count);
+            compare_metadata(reader, animated_gif_plain_2, count);
 
             IWICMetadataReader_Release(reader);
         }