Created attachment 80798 [details] CSS test case tested on WebKit version: 534.17+ Setting an element's box-flex value to zero after a document has already loaded does not shrink the element to size as expected. Instead, the element retains its former flexed size while neighboring elements are pushed beyond their parent container's bounds. Having an element with an initial box-flex of zero does behave correctly, as does modifying an element's box-flex value immediately following document load. The problem only manifests when JavaScript modifies the value some time after the document has loaded using an event handler.
Safari fails this test. Chrome and Firefox match.
<rdar://problem/96909945>