[poppler] A memory leak in GlobalParams::~GlobalParams()?

[mpsuzuki at hiroshima-u.ac.jp]

Hi,

I'm quite sorry for keeping this thread.

In fontconfig mail list, Behdad proposed to use FcFini()
to free FcConfig object. It does not require the pointer
to FcConfig object, so it works even out of the deletion
process of GlobalParams object, aslike:

diff --git a/utils/pdftotext.cc b/utils/pdftotext.cc
index 4ebda19..9c6e93e 100644
--- a/utils/pdftotext.cc
+++ b/utils/pdftotext.cc
@@ -337,6 +336,9 @@ int main(int argc, char *argv[]) {
   uMap->decRefCnt();
  err1:
   delete globalParams;
+#if WITH_FONTCONFIGURATION_FONTCONFIG
+  FcFini();
+#endif
  err0:
 
   // check for memory leaks


The valgrind reports no leaks. However, the strange reference
counting issue is left in fontconfig, so FcFini() should not be
invoked from GlobalParams::~GlobalParams().

On Thu, 21 Jan 2010 19:56:06 +0000
Albert Astals Cid <aacid at kde.org> wrote:
>A Dijous, 21 de gener de 2010, mpsuzuki at hiroshima-u.ac.jp va escriure:
>> Do you think it's a leak but not so serious to apply
>> my wrong patch?  I understood my patch was wrong and
>> must be reworked. Anyway, I attached valgrind logs of
>> pdftotext, original one (LOG-20100121a.txt) and patched
>> one (LOG-20100121b.txt).
>
>I mean it is not a "real" leak, let me explain that, each application that 
>uses poppler has (or should have) exactly one GlobalParams object, that gets 
>constructed at the begining of the application and destroyed at the end. So 
>"fixing" that leak is merely a "let's make it right" issue, i do not maen that 
>it is not important, but i also mean we can perfectly live without this fixed 
>forever and noone will notice.

I see. Maybe my attempt freeing FcConfig object seems to be
a rubbing off the text with an eraser before putting a document
through a shredder.

Anyway, I must stop this discussion until the day when I
find a reasonable usecase that GlobalParams (or FcConfig)
objects are repeatedly created & deleted.

Thank you very much for patient discussion.

Regards,
mpsuzuki