* apt-pkg/contrib/fileutl.h:

  - store the offset in the internal fd before calculate size of
    the zlib-handled file to jump back to this place again

It jumped back to the position of the content - which is wrong as
the internal fd is compressed and even reseting to the beginning of
the file doesn't work as zlib uses an internal buffer, so while we
might haven't read anything yet zlib might have done so already…

apt-pkg/contrib/fileutl.cc

@@ -1347,6 +1347,7 @@ unsigned long long FileFd::Size()
    // gzopen in "direct" mode as well
    else if (d->gz && !gzdirect(d->gz) && size > 0)
    {
+       off_t const oldPos = lseek(iFd,0,SEEK_CUR);
        /* unfortunately zlib.h doesn't provide a gzsize(), so we have to do
 	* this ourselves; the original (uncompressed) file size is the last 32
 	* bits of the file */
@@ -1364,8 +1365,9 @@ unsigned long long FileFd::Size()
        size = tmp_size;
 #endif
 
-       if (lseek(iFd, d->seekpos, SEEK_SET) < 0)
+       if (lseek(iFd, oldPos, SEEK_SET) < 0)
 	   return _error->Errno("lseek","Unable to seek in gzipped file");
+
        return size;
    }
 #endif

debian/changelog

@@ -9,12 +9,15 @@ apt (0.8.16~exp10) UNRELEASED; urgency=low
   * apt-pkg/deb/dpkgpm.cc:
     - check if dpkg supports multiarch with --assert-multi-arch
       and if it does be always explicit about the architecture
+  * apt-pkg/contrib/fileutl.h:
+    - store the offset in the internal fd before calculate size of
+      the zlib-handled file to jump back to this place again
 
   [ Michael Vogt ]
-  * apt-pkg/contrib/fileutils.h:
+  * apt-pkg/contrib/fileutl.h:
     - fix segfault from python-apt testsuite
 
- -- David Kalnischkies <kalnischkies@gmail.com>  Fri, 13 Jan 2012 17:29:07 +0100
+ -- David Kalnischkies <kalnischkies@gmail.com>  Wed, 18 Jan 2012 00:47:54 +0100
 
 apt (0.8.16~exp9) experimental; urgency=low