Changeset 278271 in webkit

Timestamp:

May 30, 2021, 11:39:50 PM (5 years ago)

Author:

Wenson Hsieh

Message:

REGRESSION (r258118): SVG paths that contain a single move command incorrect client bounding rects
​https://bugs.webkit.org/show_bug.cgi?id=226447
rdar://72112744

Reviewed by Alan Bujtas.

Source/WebCore:

r258118 introduced a fast path for computing the bounding rect of a WebCore::Path without having to
materialize a platform path object (e.g. CGPathRef on platforms that use CoreGraphics). To do this, we
introduce InlinePathData -- a variant capable of representing several types of simple Path objects without
allocating a platform path.

However, in the case where a Path only consists of a single moveTo command, this fast path for computing the
bounding rect currently returns the zero rect (an empty rect at the origin), rather than an empty rect at the
location we've moved to. This causes the offset of the bounding rect of an SVG path element that contains only a
single M drawing command to be incorrect.

Simply fix this by returning an empty rect that is offset by the moveTo location, rather than the origin.

Test: fast/svg/bounding-rect-for-path-with-only-move-command.html

• platform/graphics/Path.cpp:

(WebCore::Path::boundingRectFromInlineData const):

LayoutTests:

Add a layout test to exercise the bug.

• fast/svg/bounding-rect-for-path-with-only-move-command-expected.txt: Added.
• fast/svg/bounding-rect-for-path-with-only-move-command.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/svg/bounding-rect-for-path-with-only-move-command-expected.txt (added)
• LayoutTests/fast/svg/bounding-rect-for-path-with-only-move-command.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/platform/graphics/Path.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2021-05-30  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        REGRESSION (r258118): SVG paths that contain a single move command incorrect client bounding rects
+        https://bugs.webkit.org/show_bug.cgi?id=226447
+        rdar://72112744
+
+        Reviewed by Alan Bujtas.
+
+        Add a layout test to exercise the bug.
+
+        * fast/svg/bounding-rect-for-path-with-only-move-command-expected.txt: Added.
+        * fast/svg/bounding-rect-for-path-with-only-move-command.html: Added.
+
 2021-05-30  Sam Weinig  <weinig@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-05-30  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        REGRESSION (r258118): SVG paths that contain a single move command incorrect client bounding rects
+        https://bugs.webkit.org/show_bug.cgi?id=226447
+        rdar://72112744
+
+        Reviewed by Alan Bujtas.
+
+        r258118 introduced a fast path for computing the bounding rect of a `WebCore::Path` without having to
+        materialize a platform path object (e.g. `CGPathRef` on platforms that use CoreGraphics). To do this, we
+        introduce `InlinePathData` -- a variant capable of representing several types of simple `Path` objects without
+        allocating a platform path.
+
+        However, in the case where a `Path` only consists of a single `moveTo` command, this fast path for computing the
+        bounding rect currently returns the zero rect (an empty rect at the origin), rather than an empty rect at the
+        location we've moved to. This causes the offset of the bounding rect of an SVG path element that contains only a
+        single `M` drawing command to be incorrect.
+
+        Simply fix this by returning an empty rect that is offset by the `moveTo` location, rather than the origin.
+
+        Test: fast/svg/bounding-rect-for-path-with-only-move-command.html
+
+        * platform/graphics/Path.cpp:
+        (WebCore::Path::boundingRectFromInlineData const):
+
 2021-05-30  Youenn Fablet  <youenn@apple.com>
 

trunk/Source/WebCore/platform/graphics/Path.cpp

@@ -491 +491 @@
 
     if (hasInlineData<MoveData>())
-        return FloatRect { };
+        return {{ inlineData<MoveData>().location, FloatSize { } }};
 
     if (hasInlineData<LineData>()) {