Changeset 222264 in webkit

Timestamp:

Sep 20, 2017 9:02:51 AM (7 years ago)

Author:

magomez@igalia.com

Message:

[GTK] Completely garbled display in GMail
​https://bugs.webkit.org/show_bug.cgi?id=168964

Reviewed by Carlos Garcia Campos.

Do not try to decode images that are bigger than 32768 pixels, as cairo won't be able to render them,
and they will break the rendering of the rest of the page.

Covered by existent tests.

• platform/graphics/ImageBackingStore.h:

(WebCore::ImageBackingStore::isOverSize):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/ImageBackingStore.h (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2017-09-20  Miguel Gomez  <magomez@igalia.com>
+
+        [GTK] Completely garbled display in GMail
+        https://bugs.webkit.org/show_bug.cgi?id=168964
+
+        Reviewed by Carlos Garcia Campos.
+
+        Do not try to decode images that are bigger than 32768 pixels, as cairo won't be able to render them,
+        and they will break the rendering of the rest of the page.
+
+        Covered by existent tests.
+
+        * platform/graphics/ImageBackingStore.h:
+        (WebCore::ImageBackingStore::isOverSize):
+
 2017-09-20  Antti Koivisto  <antti@apple.com>
 

trunk/Source/WebCore/platform/graphics/ImageBackingStore.h

@@ -34 +34 @@
 namespace WebCore {
 
+#if USE(CAIRO)
+// Due to the pixman 16.16 floating point representation, cairo is not able to handle
+// images whose size is bigger than 32768.
+static const int cairoMaxImageSize = 32768;
+#endif
+
 class ImageBackingStore {
     WTF_MAKE_FAST_ALLOCATED;
@@ -172 +178 @@
     static bool isOverSize(const IntSize& size)
     {
+#if USE(CAIRO)
+        // FIXME: this is a workaround to avoid the cairo image size limit, but we should implement support for
+        // bigger images. See https://bugs.webkit.org/show_bug.cgi?id=177227.
+        //
+        // If the image is bigger than the cairo limit it can't be displayed, so we don't even try to decode it.
+        if (size.width() > cairoMaxImageSize || size.height() > cairoMaxImageSize)
+            return true;
+#endif
         static unsigned long long MaxPixels = ((1 << 29) - 1);
         unsigned long long pixels = static_cast<unsigned long long>(size.width()) * static_cast<unsigned long long>(size.height());