avoid segfault when calling built-in error handler

we were not correctly handling the case where the error handler
MPI_ERRORS_ARE_FATAL was called.  credit Lisandro Dalcin with finidng
the issue.
Signed-off-by: Junchao Zhang <jczhang@mcs.anl.gov>

src/include/mpierror.h

@@ -178,6 +178,12 @@ void MPIR_Err_get_string( int, char *, int, MPIR_Err_get_class_string_func_t );
 
 int MPIR_Err_set_msg( int code, const char *msg_string );
 
+/* This routine is called when there is a fatal error. Now public because file
+ * error handling is defined in a separate file from comm and win, but all
+ * three need to call it */
+void MPIR_Handle_fatal_error(struct MPID_Comm *comm_ptr,
+	const char fcname[], int errcode);
+
 #define MPIR_ERR_CLASS_MASK 0x0000007f
 #define MPIR_ERR_CLASS_SIZE 128
 #define MPIR_ERR_GET_CLASS(mpi_errno_) (mpi_errno_ & MPIR_ERR_CLASS_MASK)

src/mpi/errhan/errutil.c

@@ -117,7 +117,6 @@ static int did_err_init = FALSE; /* helps us solve a bootstrapping problem */
    with a valid value.  */
 
 static int checkValidErrcode( int, const char [], int * );
-static void handleFatalError( MPID_Comm *, const char [], int );
 
 #if MPICH_ERROR_MSG_LEVEL >= MPICH_ERROR_MSG_ALL
 static int ErrGetInstanceString( int, char [], int );
@@ -249,7 +248,7 @@ int MPIR_Err_return_comm( MPID_Comm  *comm_ptr, const char fcname[],
     {
         /* for whatever reason, we aren't initialized (perhaps error 
 	   during MPI_Init) */
-        handleFatalError(MPIR_Process.comm_world, fcname, errcode);
+        MPIR_Handle_fatal_error(MPIR_Process.comm_world, fcname, errcode);
         return MPI_ERR_INTERN;
     }
     /* --END ERROR HANDLING-- */
@@ -275,7 +274,7 @@ int MPIR_Err_return_comm( MPID_Comm  *comm_ptr, const char fcname[],
     /* --BEGIN ERROR HANDLING-- */
     if (MPIR_Err_is_fatal(errcode) || comm_ptr == NULL) {
 	/* Calls MPID_Abort */
-	handleFatalError( comm_ptr, fcname, errcode );
+	MPIR_Handle_fatal_error( comm_ptr, fcname, errcode );
         /* never get here */
     }
     /* --END ERROR HANDLING-- */
@@ -292,7 +291,7 @@ int MPIR_Err_return_comm( MPID_Comm  *comm_ptr, const char fcname[],
     if (errhandler == NULL || errhandler->handle == MPI_ERRORS_ARE_FATAL) {
         MPIU_THREAD_CS_EXIT(MPI_OBJ, comm_ptr);
 	/* Calls MPID_Abort */
-	handleFatalError( comm_ptr, fcname, errcode );
+	MPIR_Handle_fatal_error( comm_ptr, fcname, errcode );
         /* never get here */
     }
     /* --END ERROR HANDLING-- */
@@ -365,7 +364,7 @@ int MPIR_Err_return_win( MPID_Win  *win_ptr, const char fcname[], int errcode )
 	win_ptr == NULL || win_ptr->errhandler == NULL || 
 	win_ptr->errhandler->handle == MPI_ERRORS_ARE_FATAL) {
 	/* Calls MPID_Abort */
-	handleFatalError( NULL, fcname, errcode );
+	MPIR_Handle_fatal_error( NULL, fcname, errcode );
     }
     /* --END ERROR HANDLING-- */
 
@@ -432,8 +431,7 @@ static void CombineSpecificCodes( int, int, int );
 static const char *get_class_msg( int );
 
 /* --BEGIN ERROR HANDLING-- */
-/* This routine is called when there is a fatal error */
-static void handleFatalError( MPID_Comm *comm_ptr, 
+void MPIR_Handle_fatal_error( MPID_Comm *comm_ptr,
 			      const char fcname[], int errcode )
 {
     /* Define length of the the maximum error message line (or string with 

src/mpi/errhan/file_call_errhandler.c

@@ -98,6 +98,9 @@ int MPI_File_call_errhandler(MPI_File fh, int errorcode)
 	goto fn_exit;
     }
 
+    if (e->handle == MPI_ERRORS_ARE_FATAL) {
+	MPIR_Handle_fatal_error(NULL, "MPI_File_call_errhandler", errorcode);
+    }
 
     switch (e->language) {
     case MPID_LANG_C: