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-7.7.90.20140613/gdb/defs.h
===================================================================
--- gdb-7.7.90.20140613.orig/gdb/defs.h	2014-06-13 23:10:18.876623018 +0200
+++ gdb-7.7.90.20140613/gdb/defs.h	2014-06-13 23:10:52.450660505 +0200
@@ -174,6 +174,7 @@ extern void set_quit_flag (void);
 /* Flag that function quit should call quit_force.  */
 extern volatile int sync_quit_force_run;
 
+extern int quit_flag_cleanup;
 extern int immediate_quit;
 
 extern void quit (void);
Index: gdb-7.7.90.20140613/gdb/top.c
===================================================================
--- gdb-7.7.90.20140613.orig/gdb/top.c	2014-06-13 23:10:15.910619715 +0200
+++ gdb-7.7.90.20140613/gdb/top.c	2014-06-13 23:10:18.877623020 +0200
@@ -1378,7 +1378,9 @@ 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-7.7.90.20140613/gdb/utils.c
===================================================================
--- gdb-7.7.90.20140613.orig/gdb/utils.c	2014-06-13 23:10:18.878623021 +0200
+++ gdb-7.7.90.20140613/gdb/utils.c	2014-06-13 23:10:38.307644652 +0200
@@ -125,6 +125,11 @@ int job_control;
 
 int immediate_quit;
 
+/* Nonzero means we are already processing the quitting cleanups and we should
+   no longer get aborted.  */
+
+int quit_flag_cleanup;
+
 /* Nonzero means that strings with character values >0x7F should be printed
    as octal escapes.  Zero means just print the value (e.g. it's an
    international character, and the terminal or window can cope.)  */
Index: gdb-7.7.90.20140613/gdb/extension.c
===================================================================
--- gdb-7.7.90.20140613.orig/gdb/extension.c	2014-06-13 03:59:36.000000000 +0200
+++ gdb-7.7.90.20140613/gdb/extension.c	2014-06-13 23:11:32.434704853 +0200
@@ -817,6 +817,9 @@ check_quit_flag (void)
   int i, result = 0;
   const struct extension_language_defn *extlang;
 
+  if (quit_flag_cleanup)
+    return 0;
+
   ALL_ENABLED_EXTENSION_LANGUAGES (i, extlang)
     {
       if (extlang->ops->check_quit_flag != NULL)