merge segfault fix from Mario Sanchez Prada, many thanks

(closes: #561109)

apt-pkg/deb/dpkgpm.cc

@@ -879,7 +879,8 @@ bool pkgDPkgPM::Go(int OutStatusFd)
 	    const char *s = _("Can not write log, openpty() "
 	                      "failed (/dev/pts not mounted?)\n");
 	    fprintf(stderr, "%s",s);
-	    fprintf(term_out, "%s",s);
+            if(term_out)
+              fprintf(term_out, "%s",s);
 	    master = slave = -1;
 	 }  else {
 	    struct termios rtt;

debian/changelog

@@ -36,6 +36,8 @@ apt (0.7.25) UNRELEASED; urgency=low
     - add "purge" to list of known actions
   * apt-pkg/init.h:
     - add compatibility with old ABI name until the next ABI break
+  * merge segfault fix from Mario Sanchez Prada, many thanks
+    (closes: #561109)
 
   [ Brian Murray ]
   * apt-pkg/depcache.cc, apt-pkg/indexcopy.cc: