Created attachment 441745 [details] testcase User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.3a5pre) Gecko/20100426 Minefield/3.7a5pre ID:20100426040533 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.3a5pre) Gecko/20100426 Minefield/3.7a5pre ID:20100426040533 The page is not auto scrolling if you begin scrolling on table element with 'overflow:auto' and border width style. Reproducible: Always Steps to Reproduce: 1. Start Minefield with New profile 2. Open testcase 3. Click middle mouse button on table element. Actual Results: Auto scroll marker shows NS-EW. The page is not start scrolling. Expected Results: The page (ancestor element) should scroll freely.
Created attachment 441769 [details] testcase2 Eventually, this seems like a bug in the scrollWidth/scrollHeight properties of the table element. This returns in Firefox: a.clientHeight: 25 a.offsetHeight: 65 a.scrollHeight: 65 But in IE8, it returns: a.clientHeight: 25 a.offsetHeight: 65 a.scrollHeight: 25
So for normal block level elements, offsetH/W is the outer dimensions of the element, scrollH/W is the size of the content, as in a padding-box, so content+padding clientH/W is the actually displayed size of the content (again, with padding). for inline elements, such as spans, clientH/W suddenly becomes 0 ?!? (bug 561979) and for the table element, scrollH/W = offsetH/W, so it is the outer dimension of the table element. Also, I've just looked up that CSS 2.1  does only allow the overflow property on block-level (+ inline-block) and table-cell elements. This means that the usage seen in bug 561979 would be actually illegal.  http://www.w3.org/TR/CSS21/visufx.html#propdef-overflow
I filed bug 562005, for the issue mentioned in comment 1. If that bug would be fixed, this bug would be fixed automatically.
I cannot reproduce anymore in http://hg.mozilla.org/mozilla-central/rev/a31fc9052840 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/16.0 Firefox/16.0 ID:20120702030551 This was fixed by Bug 755971