Edit the css file that accompanies sidebar.xul. If you apply a border collapse style to the tree, you have a crash in the table code when you try to open a tree item. Double click on an item to open it and reproduce the crash (after you've edited the CSS file to add in the collapse rule for the tree). It appears that the arrays of border edges are out of sync when a new row gets inserted into the tree (ContentInserted notification that triggers a reflow). At the moment, no tree view can have a border collapse style because of this bug.

assigning incremental reflow and collapsing border bugs to buster

changed misc bugs to M6

setting my table bugs to M9

Sounds like a duplicate of bug 9024.

I think I have the fix for this bug, but bug 11393 is preventing me from verifying. I will check in my trivial change, which is shown below. Chris, after 11393 is fixed, can you please verify with the attached test case? void nsTableFrame::SetBorderEdgeLength(PRUint8 aSide, PRInt32 aIndex, nscoord aLength) { nsBorderEdge *border = (nsBorderEdge*) (mBorderEdges.mEdges[aSide].ElementAt(aIndex)); if (border) border->mLength = aLength; } plus 2 asserts removed, one each from nsTableFrame::ComputeVerticalCollapsingBorders and nsTableFrame::ComputeHorizontalCollapsingBorders: NS_ASSERTION(PR_FALSE, "aStartRowIndex>=rowCount in ComputeVerticalCollapsingBorders");

Test case added

More was needed than described 8/6 comments.

I forgot to mention that it was fixed using Steve's attachment. I could not find sidebar.xul as mentioned in the original comments.

Using 8/16 Apprunner on Win 95, Win 98 and Win NT, and Steve's test case from 8/6, verified bug fixed. No crashes.