"ASSERTION: Incorrect aState.mPrevChild before inserting line at end"

RESOLVED FIXED in mozilla1.9.3a1

Status

()

defect
RESOLVED FIXED
10 years ago
9 years ago

People

(Reporter: jruderman, Assigned: tnikkel)

Tracking

(Blocks 2 bugs, {assertion, testcase, verified1.9.2})

Trunk
mozilla1.9.3a1
x86
macOS
Points:
---
Dependency tree / graph
Bug Flags:
wanted1.9.0.x -
in-testsuite +

Firefox Tracking Flags

(blocking1.9.2 needed, status1.9.2 .2-fixed, blocking1.9.1 needed, status1.9.1 .9-fixed)

Details

(Whiteboard: [sg:critical?])

Attachments

(2 attachments)

Posted file testcase
###!!! ASSERTION: Incorrect aState.mPrevChild before inserting line at end: 'aState.mPrevChild == mFrames.LastChild()', file /Users/jruderman/mozilla-central/layout/generic/nsBlockFrame.cpp, line 2162

bz marked a previous bug with this assertion as security-sensitive (bug 522170), so I'm filing this one as security-sensitive.
Group: core-security
On trunk this assertion shouldn't itself lead to a security problem. On 3.6 and earlier it is likely to cause a messed up frame tree, so a security problem is likely just around the corner.
So I think the problem lies with this bit of code in nsBlockFrame::ReflowInlineFrame http://mxr.mozilla.org/mozilla-central/source/layout/generic/nsBlockFrame.cpp#3838

    // If we just ended a first-letter frame or reflowed a placeholder then 
    // don't split the line and don't stop the line reflow...
    if (!(frameReflowStatus & NS_INLINE_BREAK_FIRST_LETTER_COMPLETE) && 
        nsGkAtoms::placeholderFrame != frameType) {
      // Split line after the current frame
      *aLineReflowStatus = LINE_REFLOW_STOP;
      rv = SplitLine(aState, aLineLayout, aLine, aFrame->GetNextSibling(), aLineReflowStatus);
      NS_ENSURE_SUCCESS(rv, rv);
    }

At this point *aLineReflowStatus is already LINE_REFLOW_STOP because the reflow status was break after for the frame we just reflowed, but we don't split the line because of the first letter complete check. And so we stop reflow after 1 of 2 frames on the line and when we get back to nsBlockFrame::ReflowDirtyLines mPrevChild is not the last frame on the line. Adding "|| *aLineReflowStatus == LINE_REFLOW_STOP" to the if condition fixes the asserts for me.
Posted patch patchSplinter Review
Assignee: nobody → tnikkel
Attachment #423615 - Flags: review?(roc)
http://hg.mozilla.org/mozilla-central/rev/537f60b8e8df
Status: NEW → RESOLVED
Closed: 10 years ago
Flags: in-testsuite?
Resolution: --- → FIXED
Target Milestone: --- → mozilla1.9.3a1
After some bake time on trunk this is something that would probably be good to have on the branches.
blocking1.9.1: --- → ?
blocking1.9.2: --- → ?
blocking1.9.1: ? → needed
blocking1.9.2: ? → needed
Whiteboard: [sg:critical?]
Attachment #423615 - Flags: approval1.9.2.2?
Attachment #423615 - Flags: approval1.9.1.9?
Comment on attachment 423615 [details] [diff] [review]
patch

a=beltzner for 1.9.2.2 and 1.9.1.9
Attachment #423615 - Flags: approval1.9.2.2?
Attachment #423615 - Flags: approval1.9.2.2+
Attachment #423615 - Flags: approval1.9.1.9?
Attachment #423615 - Flags: approval1.9.1.9+
I notice with the testcase post-fix that I'm not seeing the assert above anymore on OS X but I do get:

###!!! ASSERTION: overflow list w/o frames: 'mFrames.NotEmpty()', file /Users/albill/mozilla-192/layout/generic/nsInlineFrame.cpp, line 374


Is this a non-issue?
I don't get that assertion on trunk, I would guess because of bug 533379 which is fixed on trunk but not 1.9.2.
Well, that isn't *this* assertion so I will call this verified1.9.2.
Keywords: verified1.9.2
verified 1.9.2-2 with Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.2) Gecko/20100321 Firefox/3.6.2 ID:20100321170417 (debug build) - the testcase didn't caused the assertion from comment #0 - for comment 10 i have made a comment in bug 533379 - maybe that bug need to land on 1.9.2 too
Flags: wanted1.9.0.x-
Group: core-security
Added crashtest
http://hg.mozilla.org/mozilla-central/rev/f8c56496ae7d
Flags: in-testsuite? → in-testsuite+
You need to log in before you can comment on or make changes to this bug.