Merge 94793 - Crashes in WebCore::ReplaceSelectionCommand::doApply

Merge 94793 - Crashes in WebCore::ReplaceSelectionCommand::doApply
https://bugs.webkit.org/show_bug.cgi?id=67762

Patch by Shinya Kawanaka <shinyak@google.com>; on 2011-09-08
Reviewed by Ryosuke Niwa.

Source/WebCore:

WebCore::enclosingBlock may return null, but its return value was not checked. This patch checks it.

Tests: editing/inserting/insert-without-enclosing-block.html

* editing/ReplaceSelectionCommand.cpp:
(WebCore::ReplaceSelectionCommand::doApply): Added null check.

LayoutTests:

WebCore::enclosingBlock may return NULL, but its return value was not checked. This patch checks it.

* editing/inserting/insert-without-enclosing-block-expected.txt: Added.
* editing/inserting/insert-without-enclosing-block.html: Added.

TBR=sullivan@chromium.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=94879