Bug 212688

Summary: [Win] Some Tibetan characters aren't shown
Product: WebKit Reporter: Fujii Hironori <fujii.hironori>
Component: PlatformAssignee: Nobody <webkit-unassigned>
Status: NEW    
Severity: Normal    
Priority: P2    
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
[Screenshot] WinCairo port
none
DOTTED CIRCLE + TIBETAN ASTROLOGICAL SIGN SDONG TSHUGS
none
[Screenshot] WinCairo (after r262804)
none
[Screenshot] Tibetan Wikipedia in WinCairo (after r262804) none

Fujii Hironori
Reported 2020-06-03 01:13:14 PDT
[Win] Some Tibetan characters aren't shown Both AppleWin and WinCairo have the issue. https://unicode.org/charts/nameslist/c_0F00.html https://ja.wikipedia.org/wiki/%E3%83%81%E3%83%99%E3%83%83%E3%83%88%E8%AA%9E
Attachments
[Screenshot] WinCairo port (39.15 KB, image/png)
2020-06-03 01:15 PDT, Fujii Hironori 		no flags
Details
DOTTED CIRCLE + TIBETAN ASTROLOGICAL SIGN SDONG TSHUGS (17 bytes, text/html)
2020-06-03 01:17 PDT, Fujii Hironori 		no flags
Details
[Screenshot] WinCairo (after r262804) (43.92 KB, image/png)
2020-06-09 19:01 PDT, Fujii Hironori 		no flags
Details
[Screenshot] Tibetan Wikipedia in WinCairo (after r262804) (98.10 KB, image/png)
2020-06-09 19:03 PDT, Fujii Hironori 		no flags
Details
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.
Fujii Hironori
Comment 1 2020-06-03 01:15:38 PDT
Created attachment 400906 [details] [Screenshot] WinCairo port
Fujii Hironori
Comment 2 2020-06-03 01:17:58 PDT
Created attachment 400907 [details] DOTTED CIRCLE + TIBETAN ASTROLOGICAL SIGN SDONG TSHUGS
Fujii Hironori
Comment 3 2020-06-08 13:12:23 PDT
FontCache::systemFallbackForCharacters of FontCacheWin.cpp is using three steps to choose a fallback font. 1. Try IMLangFontLink::MapFont method 2. If no font found, try meta file method 3. If no font found, try FontLink registry method For the missing Tibetan characters, IMLangFontLink::MapFont method returns "Arial Unicode MS" font, but Uniscribe returns USP_E_SCRIPT_NOT_IN_FONT for the font. For other Tibetan characters, IMLangFontLink::MapFont method returns "Microsoft Himalaya" font
Fujii Hironori
Comment 4 2020-06-08 16:36:54 PDT
Following StackOverflow suggests reffering Chromium's render_text_win.cc. How to automatically choose most suitable font for different language? - Stack Overflow https://stackoverflow.com/q/16828868 Check if Unicode character is displayed or tofu - Stack Overflow https://stackoverflow.com/q/47840800 Chromium UI was using Uniscribe, but it was replaced by HarfBuzz. https://codereview.chromium.org/891013003 https://chromium.googlesource.com/chromium/src.git/+/2e9885788692f69203a98fb42347428ef553d640/ui/gfx/render_text_win.cc https://chromium.googlesource.com/chromium/src.git/+/2e9885788692f69203a98fb42347428ef553d640/ui/gfx/font_fallback_win.cc
Fujii Hironori
Comment 5 2020-06-09 19:01:11 PDT
Created attachment 401504 [details] [Screenshot] WinCairo (after r262804) r262804 (Bug 212947) changed the situation. After the change, some Tibetan characters start to show while combining marks still doesn't render correctly.
Fujii Hironori
Comment 6 2020-06-09 19:03:07 PDT
Created attachment 401505 [details] [Screenshot] Tibetan Wikipedia in WinCairo (after r262804) Tibetan pages look broken. https://bo.wikipedia.org/
Fujii Hironori
Comment 7 2020-06-09 21:27:20 PDT
I'm going to try stop using MLang font linking in the following ticket. Bug 213008 – [Win] Stop using MLang font linking for system font fallback
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