psql: Improve tab completion of WITH

Only match when WITH is the first word, as WITH may appear in many
other contexts.

Josh Kupershmidt

src/bin/psql/tab-complete.c

@@ -2842,7 +2842,10 @@ psql_completion(char *text, int start, int end)
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_tables, NULL);
 
 /* WITH [RECURSIVE] */
-	else if (pg_strcasecmp(prev_wd, "WITH") == 0)
+	/* Only match when WITH is the first word, as WITH may appear in many other
+	   contexts. */
+	else if (pg_strcasecmp(prev_wd, "WITH") == 0 &&
+			 prev2_wd[0] == '\0')
 		COMPLETE_WITH_CONST("RECURSIVE");
 
 /* ANALYZE */