From f8465828e50f5cd7f784b1dbb400f3cb83046b17 Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Thu, 6 Feb 2014 00:25:32 -0800
Subject: [PATCH] Maybe the right way to handle empty arrays?

The previous check for the array length being 0 didn't work
for the case of an array that contains only an empty array.

The tricky part is that the current node is the array when
the array has just begun or just after a comma, but also
when the completed array has been passed off to the caller.
---
 jsonpull.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/jsonpull.c b/jsonpull.c
index cbf03714..388f1568 100644
--- a/jsonpull.c
+++ b/jsonpull.c
@@ -110,7 +110,10 @@ static void string_free(struct string *s) {
 }
 
 json_object *json_parse(FILE *f, json_object *current) {
-	int c = getc(f);
+	int current_is_container = 0;
+	int c;
+again:
+	c = getc(f);
 	if (c == EOF) {
 		return NULL;
 	}
@@ -127,14 +130,16 @@ json_object *json_parse(FILE *f, json_object *current) {
 	/////////////////////////// Arrays
 
 	if (c == '[') {
-		return json_parse(f, add_object(JSON_ARRAY, current));
+		current = add_object(JSON_ARRAY, current);
+		current_is_container = 1;
+		goto again;
 	} else if (c == ']') {
 		if (current == NULL) {
 			json_error("] at top level");
 		}
 
-		if (current->type == JSON_ARRAY && current->length == 0) {
-			return current; // Empty array
+		if (current_is_container) { // Empty array
+			return current;
 		}
 
 		if (current->parent == NULL || current->parent->type != JSON_ARRAY) {
@@ -147,14 +152,16 @@ json_object *json_parse(FILE *f, json_object *current) {
 	/////////////////////////// Hashes
 
 	if (c == '{') {
-		return json_parse(f, add_object(JSON_HASH, current));
+		current = add_object(JSON_HASH, current);
+		current_is_container = 1;
+		goto again;
 	} else if (c == '}') {
 		if (current == NULL) {
 			json_error("} at top level");
 		}
 
-		if (current->type == JSON_HASH && current->length == 0) {
-			return current; // Empty hash
+		if (current_is_container) { // Empty hash
+			return current;
 		}
 
 		if (current->parent == NULL || current->parent->type != JSON_HASH) {
@@ -210,7 +217,9 @@ json_object *json_parse(FILE *f, json_object *current) {
 			json_error(", not in array or hash\n");
 		}
 
-		return json_parse(f, current->parent);
+		current = current->parent;
+		current_is_container = 1;
+		goto again;
 	}
 
 	/////////////////////////// Colon
@@ -227,7 +236,9 @@ json_object *json_parse(FILE *f, json_object *current) {
 			json_error(": without key\n");
 		}
 
-		return json_parse(f, current->parent);
+		current = current->parent;
+		current_is_container = 1;
+		goto again;
 	}
 
 	/////////////////////////// Numbers