apt-get crashed with SIGSEGV in __fprintf_chk()

StacktraceTop:
 ___fprintf_chk (fp=0x0, flag=1, format=0x7fd7b01b4e46 "End-Date: %s\n")
 pkgDPkgPM::CloseLog (this=<value optimized out>)
 pkgDPkgPM::Go (this=0x9097b0,
 pkgPackageManager::DoInstallPostFork (
 InstallPackages (Cache=<value optimized out>,

I think crash happens because code snippet below (from apt-pkg/deb/dpkgpm.cc:656) does not check if history_out is valid.

   string history_name = flCombine(_config->FindDir("Dir::Log"),
                                   _config->Find("Dir::Log::History"));
   if (!history_name.empty())
   {
      FILE *history_out = fopen(history_name.c_str(),"a");
      fprintf(history_out, "End-Date: %s\n", timestr);
      fclose(history_out);
   }

Problem gets triggered for me because my Dir::Log directory does not exists, due to the fact I've mounted my /var/log to a tmpfs.

$apt-config dump
...
Dir::Log "var/log/apt";
Dir::Log::Terminal "term.log";
Dir::Log::History "history.log";
...

I can confirm issue has disappeared after I've created directory manually.

Here is a patch to fix the problem. I've tested it with latest apt bzr branch.
After changes, apt-get logs the following lines instead of giving a segmentation fault.

E: Directory '/var/log/apt/' missing
E: Directory '/var/log/apt/' missing

I mount my /var/log on a ramfs (since I run off a 4G thumbdrive), and worked around the problem by creating any necessary directories in rc.local. I've also created in rc.local a link from /var/cache/apt to a /tmp/debs (with /tmp mounted as tmpfs) and create the /archives/partial directory (path). Postgres also needs a directory. This setup puts some of the most active write locations into ram, instead of (slow) flash, which has a limited lifespan.

Look like 595795

I'll mark this bug as a dup of bug 535509 as we already have a branch attached there.