WebCore:

WebCore:

        Reviewed by Adam.

        <rdar://problem/5418891> CrashTracer: [USER] 1 crash in Mail at -[WebViewEditor webView:shouldInsertText:replacingDOMRange:givenAction:]

        * editing/BreakBlockquoteCommand.cpp:
        (WebCore::BreakBlockquoteCommand::doApply): We're reusing the topBlockquote
        variable.  Null it out first.  If there is no new topBlockquote and we don't null
        it out first, we'll assume that there was a new one and crash.

LayoutTests:

        Reviewed by Adam.

        <rdar://problem/5418891> CrashTracer: [USER] 1 crash in Mail at -[WebViewEditor webView:shouldInsertText:replacingDOMRange:givenAction:]

        * editing/inserting/5418891.html: Added.
        * platform/mac/editing/inserting: Added.
        * platform/mac/editing/inserting/5418891-expected.checksum: Added.
        * platform/mac/editing/inserting/5418891-expected.png: Added.
        * platform/mac/editing/inserting/5418891-expected.txt: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@25192 268f45cc-cd09-0410-ab3c-d52691b4dbfc