bug#23522: 25.0.93; SEGFAULT when displaying HELLO

[Michael Welsh Duggan]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Michael Welsh Duggan <mwd@md5i.com>
>> Cc: Michael Welsh Duggan <mwd@md5i.com>,  mwd@cert.org,  
>> 23522@debbugs.gnu.org
>> Date: Fri, 13 May 2016 14:06:28 -0400
>> 
>> > Anyway, this sounds more and more like a bug in one of the libraries
>> > Emacs uses, so I hope Handa-san will be able to chime in, since he is
>> > one of the maintainers of those libraries.
>> 
>> Quite possible.  The most important thing, in my mind, is to prevent the
>> crash if at all possible.  That could be done either by writing code to
>> catch this type of error, or by blacklisting in configure certain
>> versions of the library (assuming that this is reasonable, or possible,
>> or a real solution at all).
>
> Can you tell what versions are installed on the faulty system?

On the faulty system, m17n is 1.5.5.  The font package
(lohit-gujarati-fonts) is 2.4.4 (Oct 27 2009)

On the working system, m17n is 1.6.4.  The font package
(fonts-lohit-gujr)  is 2.92.2 (Jan 2 2014)

I have installed the Ligit Gujarati font on the working system.  The
info that comes back on the character is below:

             position: 383 of 3322 (11%), column: 16
            character: સ (displayed as સ) (codepoint 2744, #o5270, #xab8)
    preferred charset: mule-unicode-0100-24ff (Unicode characters of the range 
U+0100..U+24FF.)
code point in charset: 0x3978
               script: gujarati
               syntax: w        which means: word
             category: .:Base, L:Left-to-right (strong)
             to input: type "C-x 8 RET ab8" or "C-x 8 RET GUJARATI LETTER SA"
          buffer code: #xE0 #xAA #xB8
            file code: ESC #x24 #x2C #x31 #x39 #x78 (encoded by coding system 
iso-2022-7bit-unix)
              display: composed to form "સ્તે" (see below)

Composed with the following character(s) "્તે" using this font:
  xft:-unknown-Lohit Gujarati-normal-normal-normal-*-15-*-*-*-*-0-iso10646-1
by these glyphs:
  [0 3 0 221 8 0 8 10 0 nil]
  [0 3 2724 81 10 0 9 9 1 nil]
  [0 3 2759 110 0 -9 -1 14 -9 nil]

Character code properties: customize what to show
  name: GUJARATI LETTER SA
  general-category: Lo (Letter, Other)
  decomposition: (2744) ('સ')

There are text properties here:
  charset              mule-unicode-0100-24ff

I cannot easily install a more recent version of the font on my work
machine (the one on which Emacs crashes).

Here is the font changelog file between the revisions:

                                  lohit-gujarati
Current Version :- 2.92.2

* Thu Jan 02 2014 Pravin Satpute <psatpute@redhat.com> - 2.92.2
- Resolved issue #31: ttf Error - not valid font
- corrected direction and fixed open contour issue

* Thu Dec 12 2013 Pravin Satpute <psatpute@redhat.com> - 2.92.1
- Added 12 imatra glyphs
- Fixes "DHA + HALANT + RA" ligature #issues16
- Improved test file


* Fri Dec 06 2013 Pravin Satpute <psatpute@redhat.com> - 2.92.0
- Added 32 imatra glyphs to match variable characters width.
- Improved consistency in glyph naming, #issue29
- Improved shape of half character DHA-ધ (U+0AA7) #issues16
- Fixed ligature rules for છ્ય #issues17
- Added ligatures for ivowelsignguj + reph "ર્થિં"  #issues18
- Fixed imatra િ (0ABF) issues on W7 with MS office 7#  #issues19
- Fixed rendering of some ligature on W8 #issues25
- Fixed regression issues of ડ્ય (0AA1 + 0ACD + 0AAF) #issues27
- Proper imatra for શ્વિ ligature #issues28


* Sun Nov 17 2013 Pravin Satpute <psatpute@redhat.com> - 2.91.0
- First release of Gujarati after re-writing all rules
- Open type rules are available in .fea file for easy reusability.
- Supports 'gjr2' and 'gujr' both.
- Follows AGL guidelines
- Testing done with Harbufzz and Uniscribe
- Removed the rakkar glyphs for "cha","tta","ttha","dda","ddha" & written rule 
seperately for them for trakkar form(ra_virama_uvowel & ra_virama_uuvowel)
- added iivowelsigngujarati EMatras to match glyph widths.
- Removed <Cons>+<Halant> ligatures.
- Test file available with tarball.

* Fri Dec 21 2012 Pravin Satpute <psatpute@redhat.com> - 2.5.3
- Dropping RFN from OFL.txt
- Improved shape of Dha U+0AA7 #892305

* Thu Nov 22 2012 Pravin Satpute <psatpute@redhat.com> - 2.5.2
- Resolved #872942
- Corrected panose values

* Wed Feb 29 2012 Pravin Satpute <psatpute@redhat.com> - 2.5.1
- improved asterisk shape

* Wed Sep 21 2011 Pravin Satpute <psatpute@redhat.com> - 2.5.0
- relicensing to OFL 1.1

* Tue Oct 27 2009 Pravin Satpute <psatpute@redhat.com> - 2.4.5
- updated in .conf file
- added Indian Rupee Symbol
- removed hinting instructoins, for more information see rh bugzilla #682667

* Tue Oct 27 2009 Pravin Satpute <psatpute@redhat.com> - 2.4.4
- updated latin digit positions
- fix rh bug #530943 

-- 
Michael Welsh Duggan
(md5i@md5i.com)