Created attachment 275444 [details]
Visual of rendering defect on CSS Ribbon
A rendering regression has ben introduced since at least Safari 8+ (perhaps as early as 7) which breaks CSS triangle shapes, as shown in the snapshot. If you visit the sample url on Safari 8 or 9, you can see the ribbon at the footer of the site does not render properly in Safari 8+. All other browsers including Webkit as far back as Safari 5.1 are showing the ribbon inner edges as expected.
Looks like sub pixel.
Changed in the mid-late 160000's.
Can't reproduce in a simple reduction.
(In reply to comment #3)
> Changed in the mid-late 160000's.
> Can't reproduce in a simple reduction.
I know it a peculiar issue... After fiddling with it. One pointer I can give you is this:
If you disable the 'font-size' on #footer in the example, or set it to 1em instead of 0.938em. The problem goes away. However that isn't the font size I want, and reveal that somthing is up.
It appears the font-size is changing the pseudo(s) behavior in unexpected ways.
Is that enough info for you the assess the cause and pinpoint what was changed?
I have put together a minimal repro.
Created attachment 275461 [details]
(In reply to comment #5)
> I have put together a minimal repro.
Thanks for the reduction!
This fixes the painting issue and matches FF's border sizing behavior (floor border width to device pixel).
diff --git a/Source/WebCore/css/StyleBuilderConverter.h b/Source/WebCore/css/StyleBuilderConverter.h
index ef6b19d..f9da9da 100644
@@ -40,6 +40,7 @@
@@ -254,7 +255,7 @@ inline T StyleBuilderConverter::convertLineWidth(StyleResolver& styleResolver, C
float minimumLineWidth = 1 / styleResolver.document().deviceScaleFactor();
if (result > 0 && result < minimumLineWidth)
- return result;
+ return floorToDevicePixel(result, styleResolver.document().deviceScaleFactor());
- I am expecting tons of rebaseline on this :(
with this change getComputedStyle() reports the floored border width value, but that's also inline with what FF reports.
Created attachment 275527 [details]
Comment on attachment 275527 [details]
Attachment 275527 [details] did not pass ios-sim-ews (ios-simulator-wk2):
New failing tests:
Created attachment 275528 [details]
Archive of layout-test-results from ews124 for ios-simulator-wk2
The attached test failures were seen while running run-webkit-tests on the ios-sim-ews.
Bot: ews124 Port: ios-simulator-wk2 Platform: Mac OS X 10.10.5
Created attachment 275549 [details]
Comment on attachment 275549 [details]
Clearing flags on attachment: 275549
Committed r199034: <http://trac.webkit.org/changeset/199034>
All reviewed patches have been landed. Closing bug.