41599 2010-07-05 03:08:55 -0700 optimizeLegibility doesn't play nice with fonts that do not have a space glyph 2010-07-06 01:47:07 -0700 1 1 1 Unclassified WebKit Layout and Rendering 528+ (Nightly build) Mac (Intel) OS X 10.6 RESOLVED FIXED P2 Normal --- 0 maarten.vancoile webkit-unassigned abarth eric mitz webkit.review.bot oldest_to_newest 246552 0 maarten.vancoile 2010-07-05 03:08:55 -0700 when using "text-rendering: optimizeLegibility;" on a site with @font-face, webkit tends to clip-off part of the text. Example: http://www.fontsquirrel.com/fontfacedemo/Alpha-Echo + css: html { text-rendering: optimizeLegibility; } 246679 1 mitz 2010-07-05 09:20:57 -0700 The problem appears to be this: ERROR: Font maps SPACE and ZERO WIDTH SPACE to the same glyph. Glyph width will not be overridden. (WebCore/platform/graphics/SimpleFontData.cpp:164 void WebCore::SimpleFontData::platformGlyphInit()) 246689 2 mitz 2010-07-05 09:43:04 -0700 Further debugging shows that the problem is that the font doesn’t map the SPACE character to a glyph. WebKit substitutes the space glyph from the next font in fallback order, but in some code paths, WebKit uses the cached space width from the font itself, which is bogus. This discrepancy is what’s causing the incorrect line breaking. Specifically, in RenderBlock::findNextLineBreak(), the initialization of wordTrailingSpaceWidth should probably be changed to measure a space character instead of using the cached space width. 246708 3 60554 mitz 2010-07-05 10:35:44 -0700 Created attachment 60554 Account for font fallback in initializing wordTrailingSpaceWidth 246809 4 mitz 2010-07-05 17:11:46 -0700 Fixed in <http://trac.webkit.org/projects/webkit/changeset/62510>. 246945 5 webkit.review.bot 2010-07-06 01:47:07 -0700 http://trac.webkit.org/changeset/62510 might have broken Leopard Intel Release (Tests) 60554 2010-07-05 10:35:44 -0700 2010-07-05 15:52:43 -0700 Account for font fallback in initializing wordTrailingSpaceWidth 41599_r1.diff text/plain 1776 mitz SW5kZXg6IFdlYkNvcmUvQ2hhbmdlTG9nCj09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0tIFdlYkNvcmUvQ2hhbmdlTG9n CShyZXZpc2lvbiA2MjQ5MykKKysrIFdlYkNvcmUvQ2hhbmdlTG9nCSh3b3JraW5nIGNvcHkpCkBA IC0xLDMgKzEsMTggQEAKKzIwMTAtMDctMDUgIERhbiBCZXJuc3RlaW4gIDxtaXR6QGFwcGxlLmNv bT4KKworICAgICAgICBSZXZpZXdlZCBieSBOT0JPRFkgKE9PUFMhKS4KKworICAgICAgICBvcHRp bWl6ZUxlZ2liaWxpdHkgZG9lc24ndCBwbGF5IG5pY2Ugd2l0aCBmb250cyB0aGF0IGRvIG5vdCBo YXZlIGEgc3BhY2UgZ2x5cGgKKyAgICAgICAgaHR0cHM6Ly9idWdzLndlYmtpdC5vcmcvc2hvd19i dWcuY2dpP2lkPTQxNTk5CisKKyAgICAgICAgTm8gdGVzdCBiZWNhdXNlIG5vbmUgb2YgdGhlIGZv bnRzIGF2YWlsYWJsZSB0byBEdW1wUmVuZGVyVHJlZSBhcmUgbWlzc2luZyBhIHNwYWNlIGdseXBo LgorCisgICAgICAgICogcmVuZGVyaW5nL1JlbmRlckJsb2NrTGluZUxheW91dC5jcHA6CisgICAg ICAgIChXZWJDb3JlOjpSZW5kZXJCbG9jazo6ZmluZE5leHRMaW5lQnJlYWspOiBXaGVuIHRoZSBm b250IGRvZXMgbm90IG1hcCB0aGUgc3BhY2UgY2hhcmFjdGVyCisgICAgICAgIHRvIGEgZ2x5cGgs IGEgZmFsbGJhY2sgZm9udCBpcyB1c2VkIGZvciBzcGFjZS4gVGhlcmVmb3JlLCB3b3JkVHJhaWxp bmdTcGFjZVdpZHRoIG11c3QgYmUKKyAgICAgICAgaW5pdGlhbGl6ZWQgd2l0aCB0aGUgd2lkdGgg b2YgYSBzcGFjZSBhcyBtZWFzdXJlZCBieSB0aGUgRm9udCByYXRoZXIgdGhhbiB3aXRoIHRoZSBj YWNoZWQKKyAgICAgICAgc3BhY2Ugd2lkdGguCisKIDIwMTAtMDctMDUgIFJvYiBCdWlzICA8cnds YnVpc0BnbWFpbC5jb20+CiAKICAgICAgICAgUmV2aWV3ZWQgYnkgRGlyayBTY2h1bHplLgpJbmRl eDogV2ViQ29yZS9yZW5kZXJpbmcvUmVuZGVyQmxvY2tMaW5lTGF5b3V0LmNwcAo9PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 Ci0tLSBXZWJDb3JlL3JlbmRlcmluZy9SZW5kZXJCbG9ja0xpbmVMYXlvdXQuY3BwCShyZXZpc2lv biA2MjQyMykKKysrIFdlYkNvcmUvcmVuZGVyaW5nL1JlbmRlckJsb2NrTGluZUxheW91dC5jcHAJ KHdvcmtpbmcgY29weSkKQEAgLTE1NzMsNyArMTU3Myw3IEBAIElubGluZUl0ZXJhdG9yIFJlbmRl ckJsb2NrOjpmaW5kTmV4dExpbmUKIAogICAgICAgICAgICAgLy8gTm9uLXplcm8gb25seSB3aGVu IGtlcm5pbmcgaXMgZW5hYmxlZCwgaW4gd2hpY2ggY2FzZSB3ZSBtZWFzdXJlIHdvcmRzIHdpdGgg dGhlaXIgdHJhaWxpbmcKICAgICAgICAgICAgIC8vIHNwYWNlLCB0aGVuIHN1YnRyYWN0IGl0cyB3 aWR0aC4KLSAgICAgICAgICAgIGludCB3b3JkVHJhaWxpbmdTcGFjZVdpZHRoID0gZi50eXBlc2V0 dGluZ0ZlYXR1cmVzKCkgJiBLZXJuaW5nID8gZi5zcGFjZVdpZHRoKCkgKyB3b3JkU3BhY2luZyA6 IDA7CisgICAgICAgICAgICBpbnQgd29yZFRyYWlsaW5nU3BhY2VXaWR0aCA9IGYudHlwZXNldHRp bmdGZWF0dXJlcygpICYgS2VybmluZyA/IGYud2lkdGgoVGV4dFJ1bigmc3BhY2UsIDEpKSArIHdv cmRTcGFjaW5nIDogMDsKIAogICAgICAgICAgICAgaW50IHdyYXBXID0gdG1wVyArIGlubGluZVdp ZHRoKG8sICFhcHBsaWVkU3RhcnRXaWR0aCwgdHJ1ZSk7CiAgICAgICAgICAgICBpbnQgY2hhcldp ZHRoID0gMDsK