check for valid mmap file before cleaning up

This commit was SVN r3715.

src/mca/ptl/sm/src/ptl_sm_component.c

@@ -189,22 +189,24 @@ int mca_ptl_sm_component_close(void)
     OBJ_DESTRUCT(&mca_ptl_sm_component.sm_pending_ack);
 
     /* unmap the shared memory control structure */
-    return_value=munmap(mca_ptl_sm_component.mmap_file->map_addr,
-            mca_ptl_sm_component.mmap_file->map_size);
-    if(-1 == return_value) {
-        return_value=OMPI_ERROR;
-        ompi_output(0," munmap failed :: file - %s :: errno - %d \n",
-                mca_ptl_sm_component.mmap_file->map_addr,
-                errno);
-        goto CLEANUP;
+    if(mca_ptl_sm_component.mmap_file != NULL) {
+        return_value=munmap(mca_ptl_sm_component.mmap_file->map_addr,
+                mca_ptl_sm_component.mmap_file->map_size);
+        if(-1 == return_value) {
+            return_value=OMPI_ERROR;
+            ompi_output(0," munmap failed :: file - %s :: errno - %d \n",
+                    mca_ptl_sm_component.mmap_file->map_addr,
+                    errno);
+            goto CLEANUP;
+        }
+    
+        /* unlink file, so that it will be deleted when all references
+         * to it are gone - no error checking, since we want all procs
+         * to call this, so that in an abnormal termination scanario,
+         * this file will still get cleaned up */
+        unlink(mca_ptl_sm_component.mmap_file->map_path);
     }
 
-    /* unlink file, so that it will be deleted when all references
-     * to it are gone - no error checking, since we want all procs
-     * to call this, so that in an abnormal termination scanario,
-     * this file will still get cleaned up */
-    unlink(mca_ptl_sm_component.mmap_file->map_path);
-
 CLEANUP:
 
     /* return */