Loading the testcase triggers: ###!!! ASSERTION: something is probably wrong somewhere: '1000 != count', file /Users/jruderman/trunk/mozilla/layout/mathml/base/src/nsMathMLChar.cpp, line 2410

Decide on the maximum number of glue glyphs to draw during measuring and detect zero-sized glue, rather than leaving a big gap when painting.

Comment on attachment 295028 [details] [diff] [review] calculate maximum height when measuring + nscoord sum = 0; + if (aGlyphs[first] != aGlyphs[glue]) sum = aSizes[first]; + if (aGlyphs[middle] != aGlyphs[glue]) sum += aSizes[middle]; + if (aGlyphs[last] != aGlyphs[glue]) sum += aSizes[last]; Slight simplification: define static SizeOfNonGlueGlyph(aGlyphs, aSizes, index) and set "sum = SizeOfNonGlueGlyph(aGlyphs, aSizes, first) + SizeOfNonGlueGlyph(aGlyphs, aSizes, middle) + SizeOfNonGlueGlyph(aGlyphs, aSizes, last);" + else if (bmdata[3].ascent + bmdata[3].descent > 0) { Can we use a symbolic constant instead of 3? I guess existing code uses '3', so never mind :-( r+sr with the first comment

(In reply to comment #2) > (From update of attachment 295028 [details] [diff] [review]) > + nscoord sum = 0; > + if (aGlyphs[first] != aGlyphs[glue]) sum = aSizes[first]; > + if (aGlyphs[middle] != aGlyphs[glue]) sum += aSizes[middle]; > + if (aGlyphs[last] != aGlyphs[glue]) sum += aSizes[last]; > > Slight simplification: define static SizeOfNonGlueGlyph(aGlyphs, aSizes, > index) and set "sum = SizeOfNonGlueGlyph(aGlyphs, aSizes, first) + > SizeOfNonGlueGlyph(aGlyphs, aSizes, middle) + SizeOfNonGlueGlyph(aGlyphs, > aSizes, last);" After discussion with roc, used a while^Wfor loop instead. Checked in: layout/mathml/base/src/nsMathMLChar.cpp revision 1.137.