Several of the reftests in columns will break if the default font is changed to something like Charis SIL, which has unusually large ascent/descent metrics (because it supports stacking diacritics), and/or the default font size is significantly increased (e.g., run reftest with font size 32 instead of 16). Ideally, the reftests would be independent of such font settings. Specific tests where I ran into such failures are: column-balancing-004 columnrule-basic columnrule-complex columnrule-padding The attached patch makes the reftests more robust, by a combination of explicit font size control and/or increasing dimensions to allow for fonts with greater ascent/descent. Sufficiently bizarre fonts might still cause problems, but this makes them much more reliable in local testing here.

pushed to mozilla-central: http://hg.mozilla.org/mozilla-central/rev/4a0dfd134a38