We may abort the process of detaching threads with multiple SIGINTs - which are
being sent during a testcase terminating its child GDB.

Some of the threads may not be properly PTRACE_DETACHed which hurts if they
should have been detached with SIGSTOP (as they are accidentally left running
on the debugger termination).

Index: gdb-7.6.50.20130731-cvs/gdb/defs.h
===================================================================
--- gdb-7.6.50.20130731-cvs.orig/gdb/defs.h	2013-08-02 16:58:31.453016573 +0200
+++ gdb-7.6.50.20130731-cvs/gdb/defs.h	2013-08-02 16:58:41.221030412 +0200
@@ -177,6 +177,7 @@ extern int check_quit_flag (void);
 /* Set the quit flag.  */
 extern void set_quit_flag (void);
 
+extern int quit_flag_cleanup;
 extern int immediate_quit;
 
 extern void quit (void);
Index: gdb-7.6.50.20130731-cvs/gdb/top.c
===================================================================
--- gdb-7.6.50.20130731-cvs.orig/gdb/top.c	2013-08-02 16:58:41.222030414 +0200
+++ gdb-7.6.50.20130731-cvs/gdb/top.c	2013-08-02 16:59:06.321066228 +0200
@@ -1415,7 +1415,9 @@ quit_force (char *args, int from_tty)
   if (ex.reason < 0) \
     exception_print (gdb_stderr, ex)
 
-  /* We want to handle any quit errors and exit regardless.  */
+  /* We want to handle any quit errors and exit regardless but we should never
+     get user-interrupted to properly detach the inferior.  */
+  quit_flag_cleanup = 1;
 
   /* Get out of tfind mode, and kill or detach all inferiors.  */
   DO_TRY
Index: gdb-7.6.50.20130731-cvs/gdb/utils.c
===================================================================
--- gdb-7.6.50.20130731-cvs.orig/gdb/utils.c	2013-08-02 16:58:31.455016575 +0200
+++ gdb-7.6.50.20130731-cvs/gdb/utils.c	2013-08-02 16:58:41.223030415 +0200
@@ -136,6 +136,11 @@ int quit_flag;
 
 int immediate_quit;
 
+/* Nonzero means we are already processing the quitting cleanups and we should
+   no longer get aborted.  */
+
+int quit_flag_cleanup;
+
 #ifndef HAVE_PYTHON
 
 /* Clear the quit flag.  */
@@ -159,6 +164,9 @@ set_quit_flag (void)
 int
 check_quit_flag (void)
 {
+  if (quit_flag_cleanup)
+    return 0;
+
   /* This is written in a particular way to avoid races.  */
   if (quit_flag)
     {
Index: gdb-7.6.50.20130731-cvs/gdb/python/python.c
===================================================================
--- gdb-7.6.50.20130731-cvs.orig/gdb/python/python.c	2013-08-02 16:58:31.456016577 +0200
+++ gdb-7.6.50.20130731-cvs/gdb/python/python.c	2013-08-02 16:58:41.224030416 +0200
@@ -191,6 +191,9 @@ set_quit_flag (void)
 int
 check_quit_flag (void)
 {
+  if (quit_flag_cleanup)
+    return 0;
+
   return PyOS_InterruptOccurred ();
 }