From 7a0b9af6626e0b11231b8fb068a49dab2d5d2bd7 Mon Sep 17 00:00:00 2001
From: Vincent Bernat <bernat@luffy.cx>
Date: Sat, 15 Feb 2014 17:23:53 +0100
Subject: [PATCH] Allow to mix JSON_STRICT with optional keys

On unpack, one may want to mix `JSON_STRICT` and optional keys by using
a format like `{s:i,s?o!}`. Unfortunately, this fails the stric test
with `-1 object item(s) left unpacked` error when the second key is not
specified.

To fix that, we iter on each key and we check if we have successfully
unpacked them. This is less efficient than the previous method but it
brings correctness.
---
 src/pack_unpack.c             | 18 ++++++++++++++----
 test/suites/api/test_unpack.c | 19 +++++++++++++++++++
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/src/pack_unpack.c b/src/pack_unpack.c
index 76d946b..abed654 100644
--- a/src/pack_unpack.c
+++ b/src/pack_unpack.c
@@ -432,10 +432,20 @@ static int unpack_object(scanner_t *s, json_t *root, va_list *ap)
     if(strict == 0 && (s->flags & JSON_STRICT))
         strict = 1;
 
-    if(root && strict == 1 && key_set.size != json_object_size(root)) {
-        long diff = (long)json_object_size(root) - (long)key_set.size;
-        set_error(s, "<validation>", "%li object item(s) left unpacked", diff);
-        goto out;
+    if(root && strict == 1) {
+        /* We need to check that all non optional items have been parsed */
+        const char *key;
+        json_t *value;
+        long unpacked = 0;
+        json_object_foreach(root, key, value) {
+            if(!hashtable_get(&key_set, key)) {
+                unpacked++;
+            }
+        }
+        if (unpacked) {
+            set_error(s, "<validation>", "%li object item(s) left unpacked", unpacked);
+            goto out;
+        }
     }
 
     ret = 0;
diff --git a/test/suites/api/test_unpack.c b/test/suites/api/test_unpack.c
index fac1be3..6b76106 100644
--- a/test/suites/api/test_unpack.c
+++ b/test/suites/api/test_unpack.c
@@ -378,4 +378,23 @@ static void run_tests()
     if(i1 != 42)
         fail("json_unpack failed to unpack");
     json_decref(j);
+
+    /* Combine ? and ! */
+    j = json_pack("{si}", "foo", 42);
+    i1 = i2 = 0;
+    if(json_unpack(j, "{sis?i!}", "foo", &i1, "bar", &i2))
+        fail("json_unpack failed for optional values with strict mode");
+    if(i1 != 42)
+        fail("json_unpack failed to unpack");
+    if(i2 != 0)
+        fail("json_unpack failed to unpack");
+    json_decref(j);
+
+    /* But don't compensate a missing key with an optional one. */
+    j = json_pack("{sisi}", "foo", 42, "baz", 43);
+    i1 = i2 = i3 = 0;
+    if(!json_unpack_ex(j, &error, 0, "{sis?i!}", "foo", &i1, "bar", &i2))
+        fail("json_unpack failed for optional values with strict mode and compensation");
+    check_error("1 object item(s) left unpacked", "<validation>", 1, 8, 8);
+    json_decref(j);
 }