Title: [235516] trunk
- Revision
- 235516
- Author
- [email protected]
- Date
- 2018-08-30 12:37:37 -0700 (Thu, 30 Aug 2018)
Log Message
The width of a nullptr TextRun should be zero
https://bugs.webkit.org/show_bug.cgi?id=189154
<rdar://problem/43685926>
Reviewed by Zalan Bujtas.
Source/WebCore:
If a page has an empty TextRun and attempts to paint it we can crash with a nullptr.
This patch recognizes that an empty TextRun should always produce a zero width, rather than
attempt to compute this value from font data.
Test: fast/text/null-string-textrun.html
* platform/graphics/FontCascade.cpp:
(WebCore::FontCascade::widthOfTextRange const): An empty TextRun has zero width.
(WebCore::FontCascade::width const): Ditto.
(WebCore::FontCascade::codePath const): ASSERT that the TextRun is non-empty.
LayoutTests:
* fast/text/null-string-textrun-expected.txt: Added.
* fast/text/null-string-textrun.html: Added.
Modified Paths
Added Paths
Diff
Modified: trunk/LayoutTests/ChangeLog (235515 => 235516)
--- trunk/LayoutTests/ChangeLog 2018-08-30 19:27:56 UTC (rev 235515)
+++ trunk/LayoutTests/ChangeLog 2018-08-30 19:37:37 UTC (rev 235516)
@@ -1,3 +1,14 @@
+2018-08-30 Brent Fulgham <[email protected]>
+
+ The width of a nullptr TextRun should be zero
+ https://bugs.webkit.org/show_bug.cgi?id=189154
+ <rdar://problem/43685926>
+
+ Reviewed by Zalan Bujtas.
+
+ * fast/text/null-string-textrun-expected.txt: Added.
+ * fast/text/null-string-textrun.html: Added.
+
2018-08-30 Eric Carlson <[email protected]>
Mock video devices should only support discrete sizes
Added: trunk/LayoutTests/fast/text/null-string-textrun-expected.txt (0 => 235516)
--- trunk/LayoutTests/fast/text/null-string-textrun-expected.txt (rev 0)
+++ trunk/LayoutTests/fast/text/null-string-textrun-expected.txt 2018-08-30 19:37:37 UTC (rev 235516)
@@ -0,0 +1,6 @@
+This test confirms that a null text run doesn't trigger a crash. It passes if it loads without crashing.
+
+
+
+
+
Added: trunk/LayoutTests/fast/text/null-string-textrun.html (0 => 235516)
--- trunk/LayoutTests/fast/text/null-string-textrun.html (rev 0)
+++ trunk/LayoutTests/fast/text/null-string-textrun.html 2018-08-30 19:37:37 UTC (rev 235516)
@@ -0,0 +1,19 @@
+<!doctype html>
+<head>
+<script>
+if (window.testRunner)
+ testRunner.dumpAsText();
+</script>
+<head>
+<body>
+ <p>This test confirms that a null text run doesn't trigger a crash. It passes if it loads without crashing.</p>
+ <pre id="pre_tag" dir="RTL" >
+ <style _onload_="pre_tag.appendChild(meter_tag)"/></style>
+ <select multiple="multiple">
+ <optgroup/>
+ </select>
+ </pre>
+ <label>
+ <meter id="meter_tag">
+ </label>
+</body>
\ No newline at end of file
Modified: trunk/Source/WebCore/ChangeLog (235515 => 235516)
--- trunk/Source/WebCore/ChangeLog 2018-08-30 19:27:56 UTC (rev 235515)
+++ trunk/Source/WebCore/ChangeLog 2018-08-30 19:37:37 UTC (rev 235516)
@@ -1,3 +1,23 @@
+2018-08-30 Brent Fulgham <[email protected]>
+
+ The width of a nullptr TextRun should be zero
+ https://bugs.webkit.org/show_bug.cgi?id=189154
+ <rdar://problem/43685926>
+
+ Reviewed by Zalan Bujtas.
+
+ If a page has an empty TextRun and attempts to paint it we can crash with a nullptr.
+
+ This patch recognizes that an empty TextRun should always produce a zero width, rather than
+ attempt to compute this value from font data.
+
+ Test: fast/text/null-string-textrun.html
+
+ * platform/graphics/FontCascade.cpp:
+ (WebCore::FontCascade::widthOfTextRange const): An empty TextRun has zero width.
+ (WebCore::FontCascade::width const): Ditto.
+ (WebCore::FontCascade::codePath const): ASSERT that the TextRun is non-empty.
+
2018-08-30 Eric Carlson <[email protected]>
Mock video devices should only support discrete sizes
Modified: trunk/Source/WebCore/platform/graphics/FontCascade.cpp (235515 => 235516)
--- trunk/Source/WebCore/platform/graphics/FontCascade.cpp 2018-08-30 19:27:56 UTC (rev 235515)
+++ trunk/Source/WebCore/platform/graphics/FontCascade.cpp 2018-08-30 19:37:37 UTC (rev 235516)
@@ -341,6 +341,9 @@
ASSERT(from <= to);
ASSERT(to <= run.length());
+ if (!run.length())
+ return 0;
+
float offsetBeforeRange = 0;
float offsetAfterRange = 0;
float totalWidth = 0;
@@ -385,6 +388,9 @@
float FontCascade::width(const TextRun& run, HashSet<const Font*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
{
+ if (!run.length())
+ return 0;
+
CodePath codePathToUse = codePath(run);
if (codePathToUse != Complex) {
// The complex path is more restrictive about returning fallback fonts than the simple path, so we need an explicit test to make their behaviors match.
@@ -604,6 +610,8 @@
if (s_codePath != Auto)
return s_codePath;
+ ASSERT(run.length());
+
#if !USE(FREETYPE)
// FIXME: Use the fast code path once it handles partial runs with kerning and ligatures. See http://webkit.org/b/100050
if ((enableKerning() || requiresShaping()) && (from.value_or(0) || to.value_or(run.length()) != run.length()))
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