Changeset 199150 in webkit

Timestamp:

Apr 6, 2016 10:19:52 PM (8 years ago)

Author:

mmaxfield@apple.com

Message:

REGRESSION (r188591): thingiverse.com direct messaging UI is not rendered properly
​https://bugs.webkit.org/show_bug.cgi?id=156241
<rdar://problem/25262213>

Reviewed by Simon Fraser.

Source/WebCore:

When creating a CoreText font with a size of 0, the CoreText docs say that it will
interpret this as a missing argument, and create a font of size 12 instead. However,
this doesn't cause a problem (at least on this particular website) because we will
use CGFontGetGlyphAdvancesForStyle(), which gets scaled by the supplied font
size (which is 0). However, if you turn on text-rendering: optimizeLegibility, we
will use CTFontGetAdvancesForGlyphs() instead, which does not scale by the font size.
The solution is to detect this case, and force the advance to 0.

Test: fast/text/zero-sized-fonts.html

• platform/graphics/cocoa/FontCocoa.mm:

(WebCore::Font::platformWidthForGlyph):

LayoutTests:

• fast/text/zero-sized-fonts-expected.txt: Added.
• fast/text/zero-sized-fonts.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/text/zero-sized-fonts-expected.txt (added)
• LayoutTests/fast/text/zero-sized-fonts.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/platform/graphics/cocoa/FontCocoa.mm (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2016-04-06  Myles C. Maxfield  <mmaxfield@apple.com>
+
+        REGRESSION (r188591): thingiverse.com direct messaging UI is not rendered properly
+        https://bugs.webkit.org/show_bug.cgi?id=156241
+        <rdar://problem/25262213>
+
+        Reviewed by Simon Fraser.
+
+        * fast/text/zero-sized-fonts-expected.txt: Added.
+        * fast/text/zero-sized-fonts.html: Added.
+
 2016-04-06  Matt Baker  <mattbaker@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2016-04-06  Myles C. Maxfield  <mmaxfield@apple.com>
+
+        REGRESSION (r188591): thingiverse.com direct messaging UI is not rendered properly
+        https://bugs.webkit.org/show_bug.cgi?id=156241
+        <rdar://problem/25262213>
+
+        Reviewed by Simon Fraser.
+
+        When creating a CoreText font with a size of 0, the CoreText docs say that it will
+        interpret this as a missing argument, and create a font of size 12 instead. However,
+        this doesn't cause a problem (at least on this particular website) because we will
+        use CGFontGetGlyphAdvancesForStyle(), which gets scaled by the supplied font 
+        size (which is 0). However, if you turn on text-rendering: optimizeLegibility, we
+        will use CTFontGetAdvancesForGlyphs() instead, which does not scale by the font size.
+        The solution is to detect this case, and force the advance to 0.
+
+        Test: fast/text/zero-sized-fonts.html
+
+        * platform/graphics/cocoa/FontCocoa.mm:
+        (WebCore::Font::platformWidthForGlyph):
+
 2016-04-06  Myles C. Maxfield  <mmaxfield@apple.com>
 

trunk/Source/WebCore/platform/graphics/cocoa/FontCocoa.mm

@@ -695 +695 @@
             advance.width = 0;
         }
-    } else if (!populatedAdvance)
+    } else if (!populatedAdvance && platformData().m_size)
         CTFontGetAdvancesForGlyphs(m_platformData.ctFont(), horizontal ? kCTFontOrientationHorizontal : kCTFontOrientationVertical, &glyph, &advance, 1);