14498 2007-07-02 11:31:39 -0700 RenderContainer::positionForCoordinates contains an order of operations error 2007-07-02 17:28:52 -0700 1 1 1 Unclassified WebKit Layout and Rendering 523.x (Safari 3) All All RESOLVED FIXED P2 Normal --- 1 aroben webkit-unassigned hyatt mitz oldest_to_newest 5719 0 aroben 2007-07-02 11:31:39 -0700 Here's the code from RenderContainer::positionForCoordinates (also visible at http://trac.webkit.org/projects/webkit/browser/trunk/WebCore/rendering/RenderContainer.cpp#L58 ): int top = borderTop() + paddingTop() + isTableRow() ? 0 : renderer->xPos(); int bottom = top + renderer->contentHeight(); int left = borderLeft() + paddingLeft() + isTableRow() ? 0 : renderer->yPos(); int right = left + renderer->contentWidth(); The problem (spotted by prefast) is that the + operator has higher precedence than the ternary operator, so the code evaluates like this (note the parentheses): int top = (borderTop() + paddingTop() + isTableRow()) ? 0 : renderer->xPos(); int bottom = top + renderer->contentHeight(); int left = (borderLeft() + paddingLeft() + isTableRow()) ? 0 : renderer->yPos(); int right = left + renderer->contentWidth(); It's easy to fix (just put parentheses around the ternary expression), but I'm not sure how to make a test case. 5717 1 aroben 2007-07-02 11:33:06 -0700 Sorry, the link to the code should have been http://trac.webkit.org/projects/webkit/browser/trunk/WebCore/rendering/RenderContainer.cpp#L586 5718 2 mitz 2007-07-02 11:41:14 -0700 (In reply to comment #0) > It's easy to fix (just put parentheses around the ternary expression) That "top" goes with "xPos" and "left" goes with "yPos" looks very suspicious as well! 5708 3 15356 mitz 2007-07-02 15:05:50 -0700 Created attachment 15356 Test case for RenderContainer::positionForCoordinates 5705 4 15357 aroben 2007-07-02 16:46:43 -0700 Created attachment 15357 patch with changelog 5697 5 15357 darin 2007-07-02 16:49:02 -0700 Comment on attachment 15357 patch with changelog r=me 5699 6 aroben 2007-07-02 17:28:52 -0700 Landed as r23938 15356 2007-07-02 15:05:50 -0700 2007-07-02 15:05:50 -0700 Test case for RenderContainer::positionForCoordinates 14498 test case.html text/html 354 mitz PGh0bWw+CjxoZWFkPgogICAgPHN0eWxlPgogICAgICAgIHNwYW4geyBib3JkZXI6IDEwcHggc29s aWQgYmx1ZTsgfQogICAgICAgIGRpdiB7IGRpc3BsYXk6aW5saW5lLWJsb2NrOyB9CiAgICA8L3N0 eWxlPgo8L2hlYWQ+Cjxib2R5IGNvbnRlbnRlZGl0YWJsZT0idHJ1ZSI+CiAgICA8cD4KICAgICAg ICBDbGljayBpbnNpZGUgdGhlIHJpZ2h0IGJvcmRlci4gVGhlIGNhcmV0IHNob3VsZCBtb3ZlIGFm dGVyICZsZHF1bztiYXImcmRxdW87LgogICAgPC9wPgogICAgPHNwYW4gc3R5bGU9IiI+CiAgICAg ICAgPGRpdj5mb288L2Rpdj4KICAgICAgICA8ZGl2PmJhcjwvZGl2PgogICAgPC9zcGFuPgo8L2Jv ZHk+CjwvaHRtbD4K 15357 2007-07-02 16:46:43 -0700 2007-07-02 16:49:02 -0700 patch with changelog 0001-Fix-Bug-14498-RenderContainer-positionForCoordinat.patch text/plain 6921 aroben RnJvbSAyZjRhZDgxOWQ1YmVkYjNmNWRhNjEyMzg1ODdjMzE0MmZiZWEyYjZjIE1vbiBTZXAgMTcg 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