[Bug 506840] New: Problem in freetype causes navit to crash unless freetype is built with -fno-strict-aliasing

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Summary: Problem in freetype causes navit to crash unless freetype is built with -fno-strict-aliasing

https://bugzilla.redhat.com/show_bug.cgi?id=506840

           Summary: Problem in freetype causes navit to crash unless
                    freetype is built with -fno-strict-aliasing
           Product: Fedora
           Version: rawhide
          Platform: All
        OS/Version: Linux
            Status: NEW
          Severity: medium
          Priority: low
         Component: freetype
        AssignedTo: besfahbo at redhat.com
        ReportedBy: awilliam at redhat.com
         QAContact: extras-qa at fedoraproject.org
                CC: besfahbo at redhat.com, kevin at tigcc.ticalc.org,
                    fedora-fonts-bugs-list at redhat.com
    Classification: Fedora


I encountered a problem running SVN navit (a GPS navigation app) on F11 and
then Rawhide; it would crash as soon as it tried to render any text.

I reported this upstream, and the upstream developer Martin Schaller very
kindly investigated this extensively. He was able to isolate it to a problem in
freetype. I quote:

"I think I got something
<cp15> Can you find out what compiler flags are used to compile freetype on
redhat?
<cp15> Because it seems freetype exibits a bug when compiled without
-fno-strict-aliasing
...
<adamw> OK...so this is really a bug in freetype we should report and get
fixed, building with -fno-strict-aliasing is just a workaround, right?
<cp15> Well... Hmm... without -fno-strict-aliasing gcc makes some optimizations
which are probably not expected by freetype. Hard to say where the bug is
<adamw> yes! that does the trick indeed
 ok, so...file a bug on freetype. can you give me some more details to include?
do you know exactly where it goes wrong?
<cp15> I can only tell that it crashes in ftccmap.c line 382 at FT_ASSERT(
(FT_UInt)( char_code - node->first ) < FTC_CMAP_INDICES_MAX ); because node
seems to be corrupted or NULL or at line cmap = face->charmaps[cmap_index];
because face->charmaps seems to be corrupted
 Should have been line 406 in the second part"

So, that's what we know about the problem. Please ask if you need any more
details. A .src.rpm for navit which you can rebuild to reproduce the problem
can be found at
http://adamwill.fedorapeople.org/navit/navit-0.1.1-0.1.2347.aw_fc12.src.rpm .
Run it with a stock Fedora freetype, and it fails. Run it with stock Rawhide
freetype unchanged except by adding -fno-strict-aliasing to CFLAGS, and it
works.

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