extract_key: allow missing keys in table

The table examined by extract_key is assumed to start at entry 0,
but for a table keyed on enum isl_ast_node_type,
which will be needed in the next commit, there is no entry 0
because the first non-error value is 1 rather than 0.

It is not clear why enum isl_ast_node_type starts at 1, but since
these values appear in public headers, it seems prudent
not to change them.

Signed-off-by: Sven Verdoolaege <[email protected]>

Author: skimo-openhub

extract_key.c

@@ -34,7 +34,7 @@ static KEY KEY_EXTRACT(__isl_keep isl_stream *s, struct isl_token *tok)
 		return KEY_ERROR;
 
 	for (key = 0; key < KEY_END; ++key) {
-		if (!strcmp(name, KEY_STR[key]))
+		if (KEY_STR[key] && !strcmp(name, KEY_STR[key]))
 			break;
 	}
 	free(name);