Unblock signal before raising it in its own handler (needed with BSD
signal semantics).

--- gzip-1.3.6/gzip.c.orig	2006-11-30 00:34:53.292056000 +0100
+++ gzip-1.3.6/gzip.c	2006-11-30 18:29:19.736957250 +0100
@@ -1851,8 +1851,13 @@
 abort_gzip_signal (sig)
      int sig;
 {
+   sigset_t ss;
+
    remove_output_file ();
    signal (sig, SIG_DFL);
+   sigemptyset (&ss);
+   sigaddset (&ss, sig);
+   sigprocmask (SIG_UNBLOCK, &ss, NULL);
    raise (sig);
    abort ();
 }