Make test more robust.

config/checksrc/test_mpi_pack_external_1.c

@@ -18,6 +18,10 @@ int main(int argc, char **argv) {
 
   unsigned * uint_data = calloc(UINT_COUNT, sizeof(*uint_data));
   double * dble_data = calloc(DBLE_COUNT, sizeof(*dble_data));
+  if (!uint_data || !dble_data) {
+    fputs("failed to allocate buffers\n", stderr);
+    MPI_Abort(MPI_COMM_WORLD, 1);
+  }
 
   MPI_Aint uint_pack_size, dble_pack_size;
 
@@ -28,7 +32,12 @@ int main(int argc, char **argv) {
 
   MPI_Aint pack_size = uint_pack_size + dble_pack_size;
 
-  void * pack_buffer = malloc(pack_size);
+  void *pack_buffer = malloc((size_t)pack_size);
+  if (!pack_buffer) {
+    fprintf(stderr, "failed to allocate pack buffer to %zu chars\n",
+            (size_t)pack_size);
+    MPI_Abort(MPI_COMM_WORLD, 1);
+  }
   MPI_Aint position = 0;
 
 #ifndef WITHOUT_PACK_EXTERNAL