Fixed potential memory leak in the _editor_init_syntax_add_rule function

editor.c

@@ -66,7 +66,7 @@ static int _editor_add_macro_by_str(editor_t *editor, char *str);
 static void _editor_init_syntaxes(editor_t *editor);
 static void _editor_init_syntax(editor_t *editor, syntax_t **optret_syntax, char *name, char *path_pattern, int tab_width, int tab_to_space, srule_def_t *defs);
 static int _editor_init_syntax_by_str(editor_t *editor, syntax_t **ret_syntax, char *str);
-static void _editor_init_syntax_add_rule(syntax_t *syntax, srule_def_t *def);
+static int _editor_init_syntax_add_rule(syntax_t *syntax, srule_def_t *def);
 static int _editor_init_syntax_add_rule_by_str(syntax_t *syntax, char *str);
 static void _editor_destroy_syntax_map(syntax_t *map);
 static int _editor_init_from_rc_read(editor_t *editor, FILE *rc, char **ret_rc_data, size_t *ret_rc_data_len);
@@ -2255,15 +2255,20 @@ static int _editor_init_syntax_by_str(editor_t *editor, syntax_t **ret_syntax, c
 }
 
 // Add rule to syntax
-static void _editor_init_syntax_add_rule(syntax_t *syntax, srule_def_t *def) {
+static int _editor_init_syntax_add_rule(syntax_t *syntax, srule_def_t *def) {
     srule_node_t *node;
     node = calloc(1, sizeof(srule_node_t));
     if (def->re_end) {
         node->srule = srule_new_multi(def->re, strlen(def->re), def->re_end, strlen(def->re_end), def->fg, def->bg);
     } else {
         node->srule = srule_new_single(def->re, strlen(def->re), 0, def->fg, def->bg);
     }
-    if (node->srule) DL_APPEND(syntax->srules, node);
+    if (!node->srule) {
+        free(node);
+        return MLE_ERR;
+    }
+    DL_APPEND(syntax->srules, node);
+    return MLE_OK;
 }
 
 // Proxy for _editor_init_syntax_add_rule with str in format '<start>,<end>,<fg>,<bg>' or '<regex>,<fg>,<bg>'
@@ -2275,8 +2280,7 @@ static int _editor_init_syntax_add_rule_by_str(syntax_t *syntax, char *str) {
     args[2] = strtok(NULL, ","); if (!args[2]) return MLE_ERR;
     args[3] = strtok(NULL, ",");
     style_i = args[3] ? 2 : 1;
-    _editor_init_syntax_add_rule(syntax, &((srule_def_t){ args[0], style_i == 2 ? args[1] : NULL, atoi(args[style_i]), atoi(args[style_i + 1]) }));
-    return MLE_OK;
+    return _editor_init_syntax_add_rule(syntax, &((srule_def_t){ args[0], style_i == 2 ? args[1] : NULL, atoi(args[style_i]), atoi(args[style_i + 1]) }));
 }
 
 // Destroy a syntax