UNCONFIRMED 108145
Italic characters overlaps with normal when set font "Arial" 
https://bugs.webkit.org/show_bug.cgi?id=108145
Summary Italic characters overlaps with normal when set font "Arial"
Chen Zhixiang
Reported 2013-01-28 19:39:21 PST
Test case: <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body> <style> body{ font-family: Arial; } </style> <i>斜体で</i>表示 </body> </html> The `で` overlaps with `表`。IE、Chromium、Opera、QtWebKit，all have this problem.
Attachments
bounding box for italic char may be error? (7.57 KB, image/png)
2013-01-28 20:57 PST, Chen Zhixiang 		no flags
Details
Test case (185 bytes, text/html)
2013-01-30 14:12 PST, Dean Jackson 		no flags
Details
Italic character should get the text run width an increment (1.56 KB, application/octet-stream)
2013-01-30 18:29 PST, Chen Zhixiang 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Chen Zhixiang
Comment 1 2013-01-28 20:03:07 PST
This problem may relate to the bounding box calculating method of italic characters —— seems it needs to be shifted right a little?
Chen Zhixiang
Comment 2 2013-01-28 20:57:52 PST
Created attachment 185143 [details] bounding box for italic char may be error?
Dean Jackson
Comment 3 2013-01-30 14:12:38 PST
Created attachment 185566 [details] Test case Works fine on MAC as far as I can tell.
Chen Zhixiang
Comment 4 2013-01-30 18:14:29 PST
I'm debugging this on Windows using Qt-4.8.4, which is not newest WebKit trunk code. However, problem seems still there after checking the code. Modifying the ```setLogicalWidthForTextRun``` function in RenderBlockLineLayout.cpp partly solves this problem, however there is something else I don't considered(it's out of my ability now): 1、italic in vertical-writing? or rtl? 2、italic angle is sloping to left? 3、italic angle is each font-specific? (Currently it's QFontEngine-level in Qt) 4、The text highlight effect is not good I also checked this problem in a iMac laptop, which may be not using the newest WebKit trunk code, —— problem is just there.
Chen Zhixiang
Comment 5 2013-01-30 18:29:28 PST
Created attachment 185650 [details] Italic character should get the text run width an increment The font engine calculates italic character's glyph advance_x as normal character, however, if we take the whole text run into consideration, the last italic character will stretch right a little which adds to the text's width. The causes text overlap if the next following character is in normal font.
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