Index: test/Analysis/Inputs/system-header-simulator-for-pthread-lock.h
===================================================================
--- /dev/null
+++ test/Analysis/Inputs/system-header-simulator-for-pthread-lock.h
@@ -0,0 +1,28 @@
+// Like the compiler, the static analyzer treats some functions differently if
+// they come from a system header -- for example, pthread_mutex* functions
+// should not invalidate regions of their arguments.
+#pragma clang system_header
+
+typedef struct {
+	void	*foo;
+} pthread_mutex_t;
+
+typedef struct {
+	void	*foo;
+} pthread_mutexattr_t;
+
+typedef struct {
+	void	*foo;
+} lck_grp_t;
+
+typedef pthread_mutex_t lck_mtx_t;
+
+extern int pthread_mutex_lock(pthread_mutex_t *);
+extern int pthread_mutex_unlock(pthread_mutex_t *);
+extern int pthread_mutex_trylock(pthread_mutex_t *);
+extern int pthread_mutex_destroy(pthread_mutex_t *);
+extern int pthread_mutex_init(pthread_mutex_t  *mutex, const pthread_mutexattr_t *mutexattr);
+extern int lck_mtx_lock(lck_mtx_t *);
+extern int lck_mtx_unlock(lck_mtx_t *);
+extern int lck_mtx_try_lock(lck_mtx_t *);
+extern void lck_mtx_destroy(lck_mtx_t *lck, lck_grp_t *grp);
Index: test/Analysis/pthreadlock.c
===================================================================
--- test/Analysis/pthreadlock.c
+++ test/Analysis/pthreadlock.c
@@ -2,31 +2,10 @@
 
 // Tests performing normal locking patterns and wrong locking orders
 
-typedef struct {
-	void	*foo;
-} pthread_mutex_t;
-
-typedef struct {
-	void	*foo;
-} pthread_mutexattr_t;
-
-typedef struct {
-	void	*foo;
-} lck_grp_t;
-
-typedef pthread_mutex_t lck_mtx_t;
-
-extern int pthread_mutex_lock(pthread_mutex_t *);
-extern int pthread_mutex_unlock(pthread_mutex_t *);
-extern int pthread_mutex_trylock(pthread_mutex_t *);
-extern int pthread_mutex_destroy(pthread_mutex_t *);
-extern int pthread_mutex_init(pthread_mutex_t  *mutex, const pthread_mutexattr_t *mutexattr);
-extern int lck_mtx_lock(lck_mtx_t *);
-extern int lck_mtx_unlock(lck_mtx_t *);
-extern int lck_mtx_try_lock(lck_mtx_t *);
-extern void lck_mtx_destroy(lck_mtx_t *lck, lck_grp_t *grp);
+#include "Inputs/system-header-simulator-for-pthread-lock.h"
 
 pthread_mutex_t mtx1, mtx2;
+pthread_mutex_t *pmtx;
 lck_mtx_t lck1, lck2;
 lck_grp_t grp1;
 
@@ -184,6 +163,21 @@
 }
 
 void
+ok21(void) {
+  pthread_mutex_lock(pmtx);    // no-warning
+  pthread_mutex_unlock(pmtx);  // no-warning
+}
+
+void
+ok22(void) {
+  pthread_mutex_lock(pmtx);    // no-warning
+  pthread_mutex_unlock(pmtx);  // no-warning
+  pthread_mutex_lock(pmtx);    // no-warning
+  pthread_mutex_unlock(pmtx);  // no-warning
+}
+
+
+void
 bad1(void)
 {
 	pthread_mutex_lock(&mtx1);	// no-warning