Closed Bug 202352 Opened 18 years ago Closed 13 years ago
ZWJ, ZWNJ with devanagari characters does not display correct glyphs
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User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.3) Gecko/20030312 Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.3) Gecko/20030312 No way of knowing if this form will be submitted in utf-8 encoding. Please see description of bug #2 and bug #3 on http://groups.google.com/groups?dq=&hl=hi&lr=&ie=UTF-8&oe=UTF-8&selm=BAY1-DAV15mrEkkRv6o0006c891%40hotmail.com Bug #2: Mozilla (and Composer) doesn't understand or display the ZeroWidthJoiner and ZeroWidthNonJoiner combinations correctly: 1. क् + त = क्त (a glyph of kta) 2. क् + ZWJ + त = क्‍त (half-ka & ta) 3. क् + ZWNJ + त = क्‌त (ka-halant & ta) Bug #3: Mozilla (and Composer) doesn't understand or display the Marathi crescent-R sequence correctly: र् + ZWJ + य = र्‍य (crescent-R & ya) In Mozilla, the cresent-R is only displayed as an r-halant-r-halant-consonant combo. For example: र्र्ह. (i.e. र् + र् + ह) Reproducible: Always Steps to Reproduce: 1. Make sure you are able to see devanagari using http://geocities.com/alkuma/seehindi.html 2. View http://groups.google.com/groups?dq=&hl=hi&lr=&ie=UTF-8&oe=UTF-8&selm=BAY1-DAV15mrEkkRv6o0006c891%40hotmail.com using IE6 on Win2k or XP with Indic installed - description of bugs 2 and 3 3. View the same url with Mozilla 1.3 - they are not displayed properly. Actual Results: On linux rh7.1 with indix using Moz 1.3, the correct glyphs for ka + halant + ta with zwj before ta are not displayed correctly. On XP with indic, using Moz 1.1, ka + halant + ta with (a) zwj before ta and (b) zwnj before ta are not displayed correctly. ra + halant + zwj + ya is not displayed correctly. Expected Results: View the same page on IE6.
See http://lxr.mozilla.org/seamonkey/source/layout/html/base/src/nsTextTransformer.cpp#1080 Before the rendering routine (implementations of nsIFontMetrics : nsFontMetricsXft, nsFontMetricsWin, nsFontMetricsOS2, nsFontMetricsMac, and so forth) see ZWNJ/ZWJ, it seems like it's stripped away in nsTextTransform. The comment in nsTextTransform.cpp says that we need to strip away ZWNJ/ZWJ for non-Arabic because they may appear in pre-shaped text. I'm not sure exactly what that means. I'll take a look at bug 192088. Mozilla-Win under Windows XP/2k should be able to handle ZWJ/ZWNJ correctly for Indic scripts (see bug 166520), but they're stripped away so that they're just lost before reaching nsFontMetricsWin.
Status: UNCONFIRMED → NEW
Ever confirmed: true
With the patch for bug 192088 backed out, bug #2 is fixed under Windows 2k/XP. Please, note that this issue(a part of complex script rendering) is highly dependent on platform/OS and toolkits so that working correctly under Win2k/XP does NOT mean that it also works for Mozilla-Xft, Mozilla-MacClassic, Mozilla-Win under Win9x/ME, Fizilla etc. For example, Mozilla-Xft does not handle ZWJ/ZWNJ correctly, let alone rendering Indic scripts. What is strange is that bug #3 is not fixed(in the sense that MS IE and Mozilla render an example given in bug #3 differently). At the moment, Mozilla-Win doesn't do anything special for complex script rendering (with the possiblie exception of BIDI handling). That is, it's delegating most of jobs to Win32 standard text APIs. On the other hand, MS IE apparently does some of jobs on its own (more exactly, it uses a different set of APIs - Uniscribe APIs instead of Win32 standard text APIs.) That may be the cause of difference in bug #3. If that's the case, I'm afraid there's not much Mozilla can do because Win32 stanard text APIs are supposed to handle this. Needless to say, Mozilla-Win can switch over to using Uniscribe APIs as MS IE does, but I guess that's beyond the scope of this bug. > No way of knowing if this form will be submitted in utf-8 encoding. If you set the encoding(Character Coding in MOzilla) to UTF-8 before submitting the form, you can enter UTF-8 text without a problem to Bugzilla.
The ZWJ problem exists in Mozilla-1.7.2 for Malayalam Characters also. I am using RH9.0, with Pango-1.5.2 & mozilla-1.7.2. Gedit renders the consonant+virama+ZWJ combination well. But mozilla displays them as splitted with a rectangle for ZWJ. Why the problem is not handled yet.
Mozilla-1.7.2 doesn't rely on Pango so that having installed Pango 1.5.2 doesn't help you in any way. If you want to take advantage of Pango, you have to do one of the follwoing two: 1. get the trunk source from the CVS and compile with '--enable-pango' 2. get either the trunk source or 1.7 branch source and apply my patch for bug 215219 and compile with '--enable-xft'
With the new textframe code, I have the same result between IE 6 and Fx. Also it's now possible to include the text to display inside the bug : 1. क् + त = क्त (a glyph of kta) 2. क् + ZWJ + त = क्त (half-ka & ta) 3. क् + ZWNJ + त = क्त (ka-halant & ta) र् + ZWJ + य = र्य (crescent-R & ya) र्र्ह. (i.e. र् + र् + ह)
A ZWNJ presence messes up the word rendering completely in Malayalam. Screenshots of how a text with ZWNJ renders in Firefox 2 and 3 are attached. You can test this URL ( http://fci.wikia.com/wiki/SMC ) in both versions of the browser.
messed up display in firefox 3 when a ZWNJ occurs (quite common in Malayalam words)
correct display of zwnj in firefox 2 with pango enabled (Fedora Core 8)
That is bug 405393
I'm not so sure what Praveen is seeing is a dup of 405393. Praven is seeing a Windows bug, and 405393 so far seems to be Mac/Linux only. In the attachment here, the display of the characters that *are* displayed seems much better under fx3 than fx2. I personally don't see a single character missing on the SMC page with fx3. The screen capture Praveen added on bug 405393 shows that his computer does not display "ല്" properly in the string "ത്തില് നിന്നും" (also "ര്ത്ഥ" and "ണ്" are broken inside "ഭക്ഷണപദാര്ത്ഥമാണ് പൊറോട്ട"). It works for me under Windows XP. Two possibilities : - Praveen has no font installed to display "ല്", "ര്ത്ഥ" and "ണ്", or - Fx is broken WRT the font he is using. Praveen, what result do you get on those word with IE ? If it's broken too, then it's probably a problem on your computer. If it does work, then try to copy/paste "ഭക്ഷണപദാര്ത്ഥമാണ് പൊറോട്ട" inside wordpad, and display it in large size using every malay font you have installed to find out by visual comparison which font IE as well as Fx are trying to use to display malay. If Wordpad can not display the string properly using any of your installed font, then it's a problem on your side, you need better fonts.
Sorry forget about the above comment, I got things seriously confused.
Do we still have this issue on Mac? The Linux issue is resolved and I think it is not an issue on Windows. So we could close this if it is not an issue on Mac anymore. Can some one test this on Mac?
On Mac I think this was fixed by bug 396137 at least for AAT fonts. See also bug 408897.
Status: NEW → RESOLVED
Closed: 13 years ago
Resolution: --- → FIXED
(In reply to comment #12) > I think it > is not an issue on Windows. It is still an issue on Windows. Tested on firefox 220.127.116.11. Attaching screenshots using the same font(Mangal) on Windows xp.
This attachment and the previous one for 18.104.22.168 displays the difference in rendering between firefox 22.214.171.124 and IE6 on windows xp with the IE6 rending being correct when the same font is used in both browsers.
This problem is fixed in the Fx 3.0 beta and nightly releases. It will not be fixed for any release of Fx 2.0
Component: Layout: CTL → Layout: Text
QA Contact: arthit → layout.fonts-and-text
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