Changeset 259595 in webkit

Timestamp:

Apr 6, 2020, 2:44:11 PM (6 years ago)

Author:

Jack Lee

Message:

Nullptr crash in CompositeEditCommand::moveParagraphContentsToNewBlockIfNecessary with draggable text
​https://bugs.webkit.org/show_bug.cgi?id=209999
<rdar://problem/58978340>

Reviewed by Ryosuke Niwa.

Source/WebCore:

VisibleParagraphStart/End may return empty VisiblePosition if no proper element or node
can be used as position candidate. Add null check for the returned VisiblePositions.

Test: fast/css/style-change-draggable-text.html

• editing/CompositeEditCommand.cpp:

(WebCore::CompositeEditCommand::moveParagraphContentsToNewBlockIfNecessary):

LayoutTests:

Added a regression test for the crash.

• fast/css/style-change-draggable-text-expected.txt: Added.
• fast/css/style-change-draggable-text.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/css/style-change-draggable-text-expected.txt (added)
• LayoutTests/fast/css/style-change-draggable-text.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/editing/CompositeEditCommand.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2020-04-06  Jack Lee  <shihchieh_lee@apple.com>
+
+        Nullptr crash in CompositeEditCommand::moveParagraphContentsToNewBlockIfNecessary with draggable text
+        https://bugs.webkit.org/show_bug.cgi?id=209999
+        <rdar://problem/58978340>
+
+        Reviewed by Ryosuke Niwa.
+
+        Added a regression test for the crash.
+
+        * fast/css/style-change-draggable-text-expected.txt: Added.
+        * fast/css/style-change-draggable-text.html: Added.
+
 2020-04-06  Jer Noble  <jer.noble@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2020-04-06  Jack Lee  <shihchieh_lee@apple.com>
+
+        Nullptr crash in CompositeEditCommand::moveParagraphContentsToNewBlockIfNecessary with draggable text
+        https://bugs.webkit.org/show_bug.cgi?id=209999
+        <rdar://problem/58978340>
+
+        Reviewed by Ryosuke Niwa.
+
+        VisibleParagraphStart/End may return empty VisiblePosition if no proper element or node
+        can be used as position candidate. Add null check for the returned VisiblePositions.
+
+        Test: fast/css/style-change-draggable-text.html
+
+        * editing/CompositeEditCommand.cpp:
+        (WebCore::CompositeEditCommand::moveParagraphContentsToNewBlockIfNecessary):
+
 2020-04-06  Jer Noble  <jer.noble@apple.com>
 

trunk/Source/WebCore/editing/CompositeEditCommand.cpp

@@ -1160 +1160 @@
     VisiblePosition visibleParagraphStart(startOfParagraph(visiblePos));
     VisiblePosition visibleParagraphEnd = endOfParagraph(visiblePos);
+    if (visibleParagraphStart.isNull() || visibleParagraphEnd.isNull())
+        return nullptr;
+
     VisiblePosition next = visibleParagraphEnd.next();
     VisiblePosition visibleEnd = next.isNotNull() ? next : visibleParagraphEnd;