[SV 63248] Ignore SIGPIPE

Don't terminate when make's output is redirected to a pipe and the
reader exits early; e.g.:
  $ echo 'all:; sleep 2' | make -f- -j2 -O |:

This lets us unlink temporary files, and tell the user that make was
not able to write its output.
Reported by Frank Heckenbach <f.heckenbach@fh-soft.de>.

* src/main.c (main): Ignore SIGPIPE.
* src/posixos.c (osync_clear): Fix a memory leak.

src/main.c

@@ -1182,6 +1182,11 @@ main (int argc, char **argv, char **envp)
   /* Useful for attaching debuggers, etc.  */
   SPIN ("main-entry");
 
+  /* Don't die if our stdout sends us SIGPIPE.  */
+#ifdef SIGPIPE
+  bsd_signal (SIGPIPE, SIG_IGN);
+#endif
+
 #ifdef HAVE_ATEXIT
   if (ANY_SET (check_io_state (), IO_STDOUT_OK))
     atexit (close_stdout);

src/posixos.c

@@ -699,6 +699,7 @@ osync_clear ()
       int r;
 
       EINTRLOOP (r, unlink (osync_tmpfile));
+      free (osync_tmpfile);
       osync_tmpfile = NULL;
     }
 }