Bug 7398 – Crash in setFocusNode if the old focus node has been detached

• Component: Layout and Rendering
• Status: RESOLVED DUPLICATE

[Graham Dennis]

While running Sandvox with the latest WebKit ToT, if one deletes all the text in the site sub-title or 'parting words' editable divs, then the editing delegate (in Sandvox) removes the text element (it becomes detached) before setFocusNode() is called. When setFocusNode is called, there is a crash caused by the assumption that if the node exists, and it isn't currently being detached, that is must have a renderer. In this case, as it has been detached, it no longer has a renderer. I have a patch which I'll attach.

The appropriate part of the crash report is below:
Exception:  EXC_BAD_ACCESS (0x0001)
Codes:      KERN_PROTECTION_FAILURE (0x0002) at 0x00000000

Thread 0 Crashed:
0   com.apple.WebCore              	0x019bcb50 WebCore::DocumentImpl::setFocusNode(KXMLCore::PassRefPtr<WebCore::NodeImpl>) + 400 (DocumentImpl.cpp:2058)
1   com.apple.WebCore              	0x019b53a8 WebCore::FrameView::dispatchMouseEvent(WebCore::AtomicString const&, WebCore::NodeImpl*, bool, int, QMouseEvent*, bool, int) + 1208 (FrameView.cpp:1038)

[Graham Dennis]

Created attachment 6637 [details]
patch

This patch seems to fix the bug for me.

[Darin Adler]

Comment on attachment 6637 [details]
patch

Patch looks good. We need a layout test for regression-testing purposes and a change log entry.

Also, did you run all the other layout tests to check that this didn't break anything?

Is this a duplicate of bug 7363?

[Graham Dennis]

The crash occurs on the same line as 7363, but this patch won't fix 7363 as in this case, the node is detached and so doesn't have a renderer. In the other case, the node is attached but still doesn't have a renderer.

*** This bug has been marked as a duplicate of 7363 ***