Better argument validation

All pointer arguments are now tested for NULL. json_string() now also
tests that strdup() succeeds. This is to ensure that no NULL values
end up in data structures.

Also desribe the different sources of errors in documentation.

1 files changed, 15 insertions, 1 deletions

diff --git a/test/testprogs/test_object.c b/test/testprogs/test_object.c
index f9839c7..540109e 100644
--- a/test/testprogs/test_object.c
+++ b/test/testprogs/test_object.c
@@ -29,6 +29,12 @@ int main()
     if(json_object_set(object, "a", string))
         fail("unable to set value");
 
+    if(!json_object_set(object, NULL, string))
+        fail("able to set NULL key");
+
+    if(!json_object_set(object, "a", NULL))
+        fail("able to set NULL value");
+
     iter = json_object_iter(object);
     if(!iter)
         fail("unable to get iterator");
@@ -105,11 +111,19 @@ int main()
         fail("unable to set value");
 
 
-    json_object_set_new(object, "foo", json_integer(123));
+    if(json_object_set_new(object, "foo", json_integer(123)))
+        fail("unable to set new value");
+
     value = json_object_get(object, "foo");
     if(!json_is_integer(value) || json_integer_value(value) != 123)
       fail("json_object_set_new works incorrectly");
 
+    if(!json_object_set_new(object, NULL, json_integer(432)))
+        fail("able to set_new NULL key");
+
+    if(!json_object_set_new(object, "foo", NULL))
+        fail("able to set_new NULL value");
+
     json_decref(string);
     json_decref(other_string);
     json_decref(object);