Comment 59 for bug 168261

Created an attachment (id=282925)
Fix v.1

But, you're in luck, getting an assist from a very unexpected direction, text rendering.

Bug 387969 added a backend for controlling whether text is rendered fast or pretty (with kerning and ligatures, if not with little hearts over the "i"s), using the already implemented text-rendering property from SVG because anyone building without SVG is "probably trying to do some kind of light embedded build"; bug 386759 enabled the pretty path for XUL and for HTML textboxes, by adding a "text-rendering: optimizeLegibility;" rule to toolkit/content/xul.css and layout/style/forms.css.

Bottom line for us is that we have four choices: live with three lines of error console spew about dropping rules because of the unknown text-rendering property at startup; get rid of the rules somehow (preprocessing, overriding, not sure what would both work and fly, since xul.css is preprocessed but forms.css is not); rewrite layout so that text-rendering doesn't rely on MOZ_SVG; enable SVG.

Given

[[[
roc: I'd prefer Thunderbird to just turn on SVG
roc: having SVG disabled there fragments our platform
]]]

I think options 2 and 3 are pretty well off the table, and I really don't want option 1, so here's option 4 :)