lib: json-parser: Add support for skipping a value that is already pa…

…rtially parsed.

Adds json_parse_skip(), which skips the remainder of the value parsed earlier by
json_parse_next(). This is needed when values need to be skipped by their value
type rather than their object member key.

src/lib/json-parser.c

@@ -672,6 +672,24 @@ void json_parse_skip_next(struct json_parser *parser)
 		parser->state = JSON_STATE_ARRAY_NEXT_SKIP;
 }
 
+void json_parse_skip(struct json_parser *parser)
+{
+	i_assert(!parser->skipping);
+	i_assert(parser->strinput == NULL);
+	i_assert(parser->state == JSON_STATE_OBJECT_NEXT ||
+		 parser->state == JSON_STATE_OBJECT_OPEN ||
+		 parser->state == JSON_STATE_ARRAY_NEXT ||
+		 parser->state == JSON_STATE_ARRAY_OPEN);
+
+	if (parser->state == JSON_STATE_OBJECT_OPEN ||
+	    parser->state == JSON_STATE_ARRAY_OPEN)
+		parser->nested_skip_count++;
+
+	parser->skipping = TRUE;
+	if (parser->state == JSON_STATE_ARRAY_NEXT)
+		parser->state = JSON_STATE_ARRAY_NEXT_SKIP;
+}
+
 static void json_strinput_destroyed(struct json_parser *parser)
 {
 	i_assert(parser->strinput != NULL);

src/lib/json-parser.h

@@ -42,6 +42,8 @@ int json_parse_next(struct json_parser *parser, enum json_type *type_r,
 /* Skip the next object value. If it's an object, its members are also
    skipped. */
 void json_parse_skip_next(struct json_parser *parser);
+/* Skip the remainder of the value parsed earlier by json_parse_next(). */
+void json_parse_skip(struct json_parser *parser);
 /* Return the following string as input stream. Returns 1 if ok, 0 if
    input stream is non-blocking and needs more input, -1 if the next token
    isn't a string (call json_parse_next()). */