From 36f89ff1d8b761c815d8993e9833e6357a57fc6b Mon Sep 17 00:00:00 2001
From: Chet Ramey <chet.ramey@case.edu>
Date: Fri, 1 Jun 2018 10:20:32 -0400
Subject: [PATCH] SIGINT trap handler SIGINT loop fix

---
 jobs.c       | 12 +++++++++++-
 patchlevel.h |  2 +-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/jobs.c b/jobs.c
index 2684632d..5ee21e10 100644
--- a/jobs.c
+++ b/jobs.c
@@ -2689,7 +2689,17 @@ wait_for (pid)
   wait_sigint_received = child_caught_sigint = 0;
   if (job_control == 0 || (subshell_environment&SUBSHELL_COMSUB))
     {
-      old_sigint_handler = set_signal_handler (SIGINT, wait_sigint_handler);
+      SigHandler *temp_sigint_handler;
+
+      temp_sigint_handler = set_signal_handler (SIGINT, wait_sigint_handler);
+      if (temp_sigint_handler == wait_sigint_handler)
+        {
+#if defined (DEBUG)
+	  internal_warning ("wait_for: recursively setting old_sigint_handler to wait_sigint_handler: running_trap = %d", running_trap);
+#endif
+        }
+      else
+	old_sigint_handler = temp_sigint_handler;
       waiting_for_child = 0;
       if (old_sigint_handler == SIG_IGN)
 	set_signal_handler (SIGINT, old_sigint_handler);
diff --git a/patchlevel.h b/patchlevel.h
index 4a65dc0f..d87b0ba7 100644
--- a/patchlevel.h
+++ b/patchlevel.h
@@ -25,6 +25,6 @@
    regexp `^#define[ 	]*PATCHLEVEL', since that's what support/mkversion.sh
    looks for to find the patch level (for the sccs version string). */
 
-#define PATCHLEVEL 20
+#define PATCHLEVEL 21
 
 #endif /* _PATCHLEVEL_H_ */
-- 
2.14.4