From 1eb850a182e6e5aa66d17d314b394e2ded30e2b5 Mon Sep 17 00:00:00 2001
From: Eric Blake <ebb9@byu.net>
Date: Wed, 16 Jul 2008 16:28:13 -0600
Subject: [PATCH] c-stack: Expose false positives when not using libsigsegv.

* modules/c-stack-tests (Files): Expand test.
* tests/test-c-stack.c (main): Add means to conditionally trigger
non-overflow SIGSEGV.
* tests/test-c-stack2.sh: New file.

Signed-off-by: Eric Blake <ebb9@byu.net>
---
 ChangeLog              | 10 +++++++++-
 modules/c-stack-tests  |  5 +++--
 tests/test-c-stack.c   | 19 +++++++++++++------
 tests/test-c-stack2.sh | 29 +++++++++++++++++++++++++++++
 4 files changed, 54 insertions(+), 9 deletions(-)
 create mode 100755 tests/test-c-stack2.sh

diff --git a/ChangeLog b/ChangeLog
index 91c45cee2..0772f2d80 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,10 +1,18 @@
+2008-07-16  Eric Blake  <ebb9@byu.net>
+
+	c-stack: Expose false positives when not using libsigsegv.
+	* modules/c-stack-tests (Files): Expand test.
+	* tests/test-c-stack.c (main): Add means to conditionally trigger
+	non-overflow SIGSEGV.
+	* tests/test-c-stack2.sh: New file.
+
 2008-07-14  Bruno Haible  <bruno@clisp.org>
 
 	* m4/libsigsegv.m4: Remove unneeded AC_PREREQ.
 	Reported by Eric Blake.
 
 2008-07-14  Sam Steingold  <sds@gnu.org>
-            Bruno Haible  <bruno@clisp.org>
+	    Bruno Haible  <bruno@clisp.org>
 
 	New module libsigsegv.
 	* modules/libsigsegv: New file.
diff --git a/modules/c-stack-tests b/modules/c-stack-tests
index 291f58d5e..5d3bc5807 100644
--- a/modules/c-stack-tests
+++ b/modules/c-stack-tests
@@ -1,6 +1,7 @@
 Files:
 tests/test-c-stack.c
 tests/test-c-stack.sh
+tests/test-c-stack2.sh
 
 Depends-on:
 exitfail
@@ -8,8 +9,8 @@ exitfail
 configure.ac:
 
 Makefile.am:
-TESTS += test-c-stack.sh
+TESTS += test-c-stack.sh test-c-stack2.sh
 TESTS_ENVIRONMENT += EXEEXT='@EXEEXT@'
 check_PROGRAMS += test-c-stack
 test_c_stack_LDADD = $(LDADD) @LIBINTL@
-MOSTLYCLEANFILES += t-c-stack.tmp
+MOSTLYCLEANFILES += t-c-stack.tmp t-c-stack2.tmp
diff --git a/tests/test-c-stack.c b/tests/test-c-stack.c
index 13c1a1256..bcf72adbd 100644
--- a/tests/test-c-stack.c
+++ b/tests/test-c-stack.c
@@ -29,11 +29,11 @@
   do									     \
     {									     \
       if (!(expr))							     \
-        {								     \
-          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
-          fflush (stderr);						     \
-          abort ();							     \
-        }								     \
+	{								     \
+	  fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
+	  fflush (stderr);						     \
+	  abort ();							     \
+	}								     \
     }									     \
   while (0)
 
@@ -62,7 +62,14 @@ main (int argc, char **argv)
 #endif
 
   if (c_stack_action (0) == 0)
-    return recurse ("\1");
+    {
+      if (1 < argc)
+	{
+	  exit_failure = 77;
+	  ++*argv[argc]; /* Intentionally dereference NULL.  */
+	}
+      return recurse ("\1");
+    }
   perror ("c_stack_action");
   return 77;
 }
diff --git a/tests/test-c-stack2.sh b/tests/test-c-stack2.sh
new file mode 100755
index 000000000..e55ff172d
--- /dev/null
+++ b/tests/test-c-stack2.sh
@@ -0,0 +1,29 @@
+#!/bin/sh
+
+tmpfiles=""
+trap 'rm -fr $tmpfiles' 1 2 3 15
+
+tmpfiles="t-c-stack2.tmp"
+
+# Sanitize exit status within a subshell, since some shells fail to
+# redirect stderr on their message about death due to signal.
+(./test-c-stack${EXEEXT} 1; exit $?) 2> t-c-stack2.tmp
+
+case $? in
+  77) if grep 'stack overflow' t-c-stack2.tmp >/dev/null ; then
+	echo 'cannot distinguish stack overflow from crash' >&2
+      else
+       cat t-c-stack2.tmp >&2
+      fi
+      (exit 77); exit 77 ;;
+  0) (exit 1); exit 1 ;;
+esac
+if grep 'program error' t-c-stack2.tmp >/dev/null ; then
+  :
+else
+  (exit 1); exit 1
+fi
+
+rm -fr $tmpfiles
+
+exit 0
-- 
2.11.0