Message style improvements

src/backend/utils/adt/arrayfuncs.c

@@ -4805,7 +4805,7 @@ array_fill_with_lower_bounds(PG_FUNCTION_ARGS)
 	if (PG_ARGISNULL(1) || PG_ARGISNULL(2))
 		ereport(ERROR,
 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
-			   errmsg("dimension array or low bound array cannot be NULL")));
+			   errmsg("dimension array or low bound array cannot be null")));
 
 	dims = PG_GETARG_ARRAYTYPE_P(1);
 	lbs = PG_GETARG_ARRAYTYPE_P(2);
@@ -4845,7 +4845,7 @@ array_fill(PG_FUNCTION_ARGS)
 	if (PG_ARGISNULL(1))
 		ereport(ERROR,
 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
-			   errmsg("dimension array or low bound array cannot be NULL")));
+			   errmsg("dimension array or low bound array cannot be null")));
 
 	dims = PG_GETARG_ARRAYTYPE_P(1);
 

src/pl/plpgsql/src/pl_exec.c

@@ -2060,7 +2060,7 @@ exec_stmt_foreach_a(PLpgSQL_execstate *estate, PLpgSQL_stmt_foreach_a *stmt)
 	if (isnull)
 		ereport(ERROR,
 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
-				 errmsg("FOREACH expression must not be NULL")));
+				 errmsg("FOREACH expression must not be null")));
 
 	/* check the type of the expression - must be an array */
 	if (!OidIsValid(get_element_type(arrtype)))

src/pl/plpython/plpython.c

@@ -3937,7 +3937,7 @@ PLy_add_exceptions(PyObject *plpy)
 	excmod = PyModule_Create(&PLy_exc_module);
 #endif
 	if (PyModule_AddObject(plpy, "spiexceptions", excmod) < 0)
-		PLy_elog(ERROR, "failed to add the spiexceptions module");
+		PLy_elog(ERROR, "could not add the spiexceptions module");
 
 /*
  * XXX it appears that in some circumstances the reference count of the

src/test/regress/expected/arrays.out

@@ -1292,9 +1292,9 @@ select array_fill('juhu'::text, array[3,3]);
 
 -- raise exception
 select array_fill(1, null, array[2,2]);
-ERROR:  dimension array or low bound array cannot be NULL
+ERROR:  dimension array or low bound array cannot be null
 select array_fill(1, array[2,2], null);
-ERROR:  dimension array or low bound array cannot be NULL
+ERROR:  dimension array or low bound array cannot be null
 select array_fill(1, array[3,3], array[1,1,1]);
 ERROR:  wrong number of array subscripts
 DETAIL:  Low bound array has different size than dimensions array.