<AWT Dev> [OpenJDK 2D-Dev] PING: RFR: 8249215: JFrame::setVisible crashed with -Dfile.encoding=UTF-8

Philip Race philip.race at oracle.com
Tue Jul 28 14:43:48 UTC 2020


1) You assume there is a font with ANSI_CHARSET in the list.
I thought I already tried to point out that if the entry looked like this

sequence.allfonts.UTF-8.ja=japanese,dingbats,symbol
instead of the current
sequence.allfonts.UTF-8.ja=alphabetic,japanese,dingbats,symbol

then I am not sure your fix in-line below will find anything and we'll 
still crash.

2) changing findFontWithCharset is still the wrong/more dangerous place 
to change this.
You may be uninintentionally changing behaviour.

My proposal won't break anything. It just finds a fall back when 
otherwise we'd crash.

I am not sure any of the CHARSET selections matter any more when using a 
unicode locale.
It is mainly about selecting the most appropriate font.

And that isn't going to work with out more changes.

At the very least we have to augment these
         subsetCharsetMap.put("japanese", "SHIFTJIS_CHARSET");
         subsetEncodingMap.put("japanese", "windows-31j");

with *something like*

         subsetCharsetMap.put("ja_utf8", "DEFAULT_CHARSET");
         subsetEncodingMap.put("japanese-utf8", "utf-8");

and also update the fontconfig file to have
sequence.allfonts.UTF-8.ja=alphabetic,ja_utf8,dingbats,symbol

and lots of fontconfig change like adding
sequence.serif.japanese-utf8=alphabetic,ja_utf8,dingbats,symbol

I haven't thought that through to see if this is exactly right but it is 
what is really missing IMO.

However having done all of that it still doesn't change that
1) There is the possibility of  a crash if not done right
2) It isn't clear that it *really matters*.

And a rearchitecture of this file and the supporting code is beyond the 
scope of what we want to do today ...

-phil

On 7/28/20, 2:21 AM, Yasumasa Suenaga wrote:
> Hi Phil
>
> Thank you so much for further investigation!
> Your change works fine on my Windows which is set to Japanese locale.
>
> However I wonder the meanings of "DEFAULT_CHARSET". It does not appear 
> to be working, right?
>
> To my understand, alphabetic font should be used if "DEFAULT_CHARSET" 
> is chosen.
> (So I think your change may be chosen "Arial,ANSI_CHARSET")
>
> Thus I think we can fix as below:
>
> ```
> diff -r 1a722ad6e23d 
> src/java.desktop/windows/classes/sun/awt/windows/WFontConfiguration.java
> --- 
> a/src/java.desktop/windows/classes/sun/awt/windows/WFontConfiguration.java  
> Tue Jul 28 09:05:36 2020 +0200
> +++ 
> b/src/java.desktop/windows/classes/sun/awt/windows/WFontConfiguration.java  
> Tue Jul 28 18:08:06 2020 +0900
> @@ -165,6 +165,9 @@
>
>      private String findFontWithCharset(FontDescriptor[] 
> fontDescriptors, String charset) {
>          String fontName = null;
> +        if (charset.equals("DEFAULT_CHARSET")) {
> +            charset = "ANSI_CHARSET";
> +        }
>          for (int i = 0; i < fontDescriptors.length; i++) {
>              String componentFontName = 
> fontDescriptors[i].getNativeName();
>              if (componentFontName.endsWith(charset)) {
> ```
>
> The following code is pointless as you said, so I agree with you to 
> remove it.
>
>>> if (fontName ==null) {
>>>      fontName = findFontWithCharset(fontDescriptors,"DEFAULT_CHARSET");
>>> }
>
>
> Thanks,
>
> Yasumasa
>
>
> On 2020/07/28 15:15, Philip Race wrote:
>> I do see some case when default is being returned.
>>
>> subsetEncodingMap.put("alphabetic", "default");
>>
>> which then needs an alphabetic font as part of the core script sequence.
>> Now looking at desc.isDefaultFont() && 
>> charset.equals("DEFAULT_CHARSET") Perhaps that could change the 
>> answer in some cases you don't intend. For these UTF 8 locales there 
>> is nothing in the fontconfig that identifies the right font. The "ja" 
>> in UTF-8.ja is not connected to "japanese" in the fontconfig file. 
>> Something like that may be the right fix but it would be a bigger 
>> change. I am not sure how much it matters either. There just needs to 
>> be a font. In the win9x days and when AWT was an "A" lib not using 
>> unicode maybe. Or maybe there's still some benefit to the right font 
>> for the language still being set as the text component font but it is 
>> not happening anyway in this case and your fix won't solve that. All 
>> roads lead to the latin/alphabetic font here. My thinking right now 
>> is to just make changes in getTextComponentFontNameso it always 
>> returns something but only after the current code fails.
>> So instead of your fix, just add this there :
>>
>> if (fontName ==null) {
>>      if (fontDescriptors.length >0) {
>>        return fontDescriptors[0].getNativeName();
>>      }else {
>>          fontName ="Arial,ANSI_CHARSET";
>>     }
>> }
>>
>> Not very satisfactory but then we can remove the comment about maybe 
>> returning NULL. -phil.
>> On 7/27/2020 5:34 PM, Philip Race wrote:
>>> This did start when we updated the fontconfiguration file but I 
>>> think there was nothing wrong with the update
>>> and I found it could happen with the previous  version if we just 
>>> remove "devanagari" from this line in the OLD version.
>>>
>>> sequence.allfonts.UTF-8.ja=alphabetic,japanese,devanagari,dingbats,symbol 
>>>
>>>
>>> Removing that mimics what happened in the new version and is the 
>>> first piece of the puzzle.
>>>
>>> I don't know why devanagari is even there. Possibly it is because 
>>> that line was derived from this one :-
>>> sequence.allfonts.UTF-8.hi=alphabetic/1252,devanagari,dingbats,symbol
>>> since hindi was the first UTF-8 locale that was supported and 
>>> someone just edited it to create the JA entry.
>>>
>>> But it indicates to me that this is quite fragile and could easily 
>>> have crashed a long time ago if Devanagari were
>>> not there as one of the "core fonts" for UTF-8.ja
>>>
>>> Then in WFontConfiguration.initTables() a few things happen
>>>
>>> first this
>>> subsetCharsetMap.put("devanagari","DEFAULT_CHARSET");
>>> subsetCharsetMap.put("japanese","SHIFTJIS_CHARSET");
>>>
>>> [for devanagari JDK specifies the Mangal font.]
>>>
>>> the subsetEncodinging map has this for Japanese
>>>   subsetEncodingMap.put("japanese", "windows-31j");
>>>
>>> then this for UTF-8 for textInputCharset
>>> }else if ("UTF-8".equals(defaultEncoding)) {
>>>      textInputCharset ="DEFAULT_CHARSET";
>>>
>>> whereas for the old ms932/windows-31j code page we would have had this
>>>
>>> }else if ("windows-31j".equals(defaultEncoding)) {
>>>      textInputCharset ="SHIFTJIS_CHARSET";
>>>
>>> it then calls makeAWTFontName("MS Gothic", "japanese");
>>> which looks like this :
>>>
>>> WFontConfiguration.makeAWTFontName(String platformFontName, String 
>>> characterSubsetName) {
>>>      String windowsCharset = subsetCharsetMap.get(characterSubsetName);
>>>      if (windowsCharset ==null) {
>>>          windowsCharset ="DEFAULT_CHARSET";
>>>      }
>>>      return platformFontName +"," + windowsCharset;
>>> }
>>>
>>> For "japanese", the result of
>>> subsetCharsetMap.get(characterSubsetName);
>>>
>>> will always be"SHIFTJIS_CHARSET"
>>>
>>> So the method will return "MS Gothic,SHIFTJIS_CHARSET"
>>> and this will get stored in the FontDescriptor
>>>
>>> The other core entries for Japanese map to ANSI_CHARSET and 
>>> SYMBOL_CHARSET.
>>>
>>> When in the old fontconfig file  is called for "devanagari", it will 
>>> return "Mangal,DEFAULT_CHARSET".
>>>
>>> Without that, there is no DEFAULT_CHARSET mapped for any font in the 
>>> core Japanese fonts.
>>>
>>> This all becomes important when 
>>> WFontConfiguration.getTextComponentFontName() is called from native 
>>> code.
>>>
>>> It has this line
>>> String fontName = findFontWithCharset(fontDescriptors, 
>>> textInputCharset);
>>>
>>> from above we know that for UTF-8 :
>>>      textInputCharset ="DEFAULT_CHARSET";
>>>
>>> but as just noted above there are NO fonts tagged with that
>>>
>>> So the look up fails. The code retries : -
>>> if (fontName ==null) {
>>>      fontName = findFontWithCharset(fontDescriptors,"DEFAULT_CHARSET");
>>> }
>>>   but that was pointless since DEFAULT_CHARSET is what was already 
>>> tried.
>>>
>>> Now back to the windows-31j locale, there we had
>>>
>>>      textInputCharset ="SHIFTJIS_CHARSET";
>>>
>>> so that finds the match "MS Gothic,SHIFTJIS_CHARSET".
>>>
>>>   getTextComponentFontName() has the comment "May return null." 
>>> which is true, but not very helpful to the native caller, which 
>>> bails out, leaving the
>>> native font structs uninitialised and ready to cause a crash.
>>>
>>> That's the kind of analysis I was hoping for !
>>>
>>> Now, the question is, is what you propose the right fix for this ?
>>> But I am not sure it can even work.
>>>
>>> 931 descriptors[i] = new FontDescriptor(awtFontName, enc, 
>>> exclusionRanges, encoding.equals("default")); seems like it will 
>>> never pass true in my testing. Then the whole fix falls apart. Can 
>>> you show some evidence ? -phil
>>>
>>>
>>> On 7/27/2020 3:50 PM, Yasumasa Suenaga wrote:
>>>> Hi Phil,
>>>>
>>>> I confirmed WFontConfiguration::findFontWithCharset cannot find if 
>>>> -Dfile.encoding=UTF-8 is passed.
>>>> I guess one of the cause is the definitions in 
>>>> make/data/fontconfig/windows.fontconfig.properties, but also 
>>>> DEFAULT_CHARSET does not work at this point.
>>>>
>>>> If we do not pass -Dfile.encoding=UTF-8, `charset` in 
>>>> WFontConfiguration::findFontWithCharset is set to "windows-31j" and 
>>>> it can find out valid font when Windows is set to Japanese locale.
>>>>
>>>> I can share minidump for further investigation. What should I do / 
>>>> share?
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> Yasumasa
>>>>
>>>>
>>>> On 2020/07/28 0:02, Philip Race wrote:
>>>>> Hi,
>>>>>
>>>>> You're avoiding a crash but I don't yet know what *exactly* caused 
>>>>> the crash.
>>>>> Some Java code not handling DEFAULT_CHARSET is obviously not the 
>>>>> exact cause.
>>>>> This just starts it and something bad presumably happens later in 
>>>>> native code.
>>>>>
>>>>> And I don't yet understand why (we think) this started happening 
>>>>> when some
>>>>> additional fonts were added to the file.
>>>>>
>>>>> Knowing exactly what is wrong will help decide if this is the 
>>>>> right fix.
>>>>>
>>>>> -phil
>>>>>
>>>>> On 7/24/20, 5:59 AM, Yasumasa Suenaga wrote:
>>>>>> Hi Jay,
>>>>>>
>>>>>> I share you hs_err log of this issue.
>>>>>> `chcp` on my console shows "932" (MS932). It is Japanese locale.
>>>>>>
>>>>>> I can share you if you want to know.
>>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Yasumasa
>>>>>>
>>>>>>
>>>>>> On 2020/07/24 20:59, Jayathirth D V wrote:
>>>>>>> Hi Yasumasa,
>>>>>>>
>>>>>>> I tried after changing the locale to Japanese but I don’t see 
>>>>>>> the issue.
>>>>>>>
>>>>>>> Also tried to reproduce the issue by enabling/disabling setting 
>>>>>>> "Beta:Use Unicode UTF-8 for worldwide language support" in my 
>>>>>>> locale setting.
>>>>>>>
>>>>>>> @Others : Can somebody else try to reproduce this issue?
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Jay
>>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Yasumasa Suenaga <suenaga at oss.nttdata.com>
>>>>>>> Sent: Thursday, July 23, 2020 5:41 PM
>>>>>>> To: Jayathirth D v <jayathirth.d.v at oracle.com>
>>>>>>> Cc: 2d-dev <2d-dev at openjdk.java.net>; awt-dev at openjdk.java.net
>>>>>>> Subject: Re: [OpenJDK 2D-Dev] PING: RFR: 8249215: 
>>>>>>> JFrame::setVisible crashed with -Dfile.encoding=UTF-8
>>>>>>>
>>>>>>> Hi Jay,
>>>>>>>
>>>>>>> On 2020/07/23 19:09, Jayathirth D v wrote:
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> I tried reproducing the issue in my Windows 10 machine with 
>>>>>>>> UTF-8 encoding and test file mentioned in the bug, I don’t see 
>>>>>>>> any crash.
>>>>>>>> Am I missing something?
>>>>>>>
>>>>>>> OS locale may be affecting.
>>>>>>>
>>>>>>> My laptop has been set Japanese (CP932 / Windows-31J), so 
>>>>>>> WFontConfiguration attempt to find Japanese font by default.
>>>>>>> However WFontConfiguration cannot find out the font of 
>>>>>>> "DEFAULT_CHARSET" when -Dfile.encoding=UTF-8 is passed.
>>>>>>>
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Yasumasa
>>>>>>>
>>>>>>>
>>>>>>>> Also I think this should be in awt-dev so adding the mailing list.
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Jay
>>>>>>>>
>>>>>>>>> On 20-Jul-2020, at 12:59 PM, Yasumasa Suenaga 
>>>>>>>>> <suenaga at oss.nttdata.com> wrote:
>>>>>>>>>
>>>>>>>>> PING: could you review it?
>>>>>>>>>
>>>>>>>>>>     JBS: https://bugs.openjdk.java.net/browse/JDK-8249215
>>>>>>>>>>     webrev: 
>>>>>>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8249215/webrev.00/
>>>>>>>>>
>>>>>>>>> Yasumasa
>>>>>>>>>
>>>>>>>>> On 2020/07/11 17:39, Yasumasa Suenaga wrote:
>>>>>>>>>> Hi all,
>>>>>>>>>> Please review this change:
>>>>>>>>>>     JBS: https://bugs.openjdk.java.net/browse/JDK-8249215
>>>>>>>>>>     webrev: 
>>>>>>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8249215/webrev.00/
>>>>>>>>>> I tried to run Sample.java in JDK-8236161 with 
>>>>>>>>>> -Dfile.encoding=UTF-8, but JVM crashed due to internal error 
>>>>>>>>>> on fastdebug VM. I saw same call stack with JDK-8236161 in 
>>>>>>>>>> hs_err log.
>>>>>>>>>> I investigated it, then I found out current implementation 
>>>>>>>>>> cannot handle default charset.
>>>>>>>>>> If charset is set to UTF-8, it would be handled as 
>>>>>>>>>> "DEFAULT_CHARSET" in WFontConfiguration::initTables. However 
>>>>>>>>>> it does not affect native font name, so we cannot find valid 
>>>>>>>>>> font.
>>>>>>>>>> This change has passed all tests on submit repo 
>>>>>>>>>> (mach5-one-ysuenaga-JDK-8249215-20200711-0655-12566039)
>>>>>>>>>> Thanks,
>>>>>>>>>> Yasumasa
>>>>>>>>
>>>
>>


More information about the awt-dev mailing list