Fix reference counting on true, false and null

Initialize their reference counts to (unsigned int)-1 to disable
reference counting on them. It already was meant to work like this,
but the reference counts were just initialized to 1 instead of -1.

Thanks to Andrew Thompson for reporting this issue.

diff --git a/src/value.c b/src/value.c
index 345ff8e..3fa7ee3 100644 (file)
--- a/src/value.c
+++ b/src/value.c
@@ -784,7 +784,7 @@ json_t *json_true(void)
 {
     static json_t the_true = {
         .type = JSON_TRUE,
-        .refcount = (unsigned int)1
+        .refcount = (unsigned int)-1
     };
     return &the_true;
 }
@@ -794,7 +794,7 @@ json_t *json_false(void)
 {
     static json_t the_false = {
         .type = JSON_FALSE,
-        .refcount = (unsigned int)1
+        .refcount = (unsigned int)-1
     };
     return &the_false;
 }
@@ -804,7 +804,7 @@ json_t *json_null(void)
 {
     static json_t the_null = {
         .type = JSON_NULL,
-        .refcount = (unsigned int)1
+        .refcount = (unsigned int)-1
     };
     return &the_null;
 }

diff --git a/test/suites/api/test_simple.c b/test/suites/api/test_simple.c
index 45f22c7..1769c65 100644 (file)
--- a/test/suites/api/test_simple.c
+++ b/test/suites/api/test_simple.c
@@ -150,5 +150,36 @@ int main()
         fail("json_null failed");
     json_decref(value);
 
+    /* Test reference counting on singletons (true, false, null) */
+    value = json_true();
+    if(value->refcount != (unsigned int)-1)
+      fail("refcounting true works incorrectly");
+    json_decref(value);
+    if(value->refcount != (unsigned int)-1)
+      fail("refcounting true works incorrectly");
+    json_incref(value);
+    if(value->refcount != (unsigned int)-1)
+      fail("refcounting true works incorrectly");
+
+    value = json_false();
+    if(value->refcount != (unsigned int)-1)
+      fail("refcounting false works incorrectly");
+    json_decref(value);
+    if(value->refcount != (unsigned int)-1)
+      fail("refcounting false works incorrectly");
+    json_incref(value);
+    if(value->refcount != (unsigned int)-1)
+      fail("refcounting false works incorrectly");
+
+    value = json_null();
+    if(value->refcount != (unsigned int)-1)
+      fail("refcounting null works incorrectly");
+    json_decref(value);
+    if(value->refcount != (unsigned int)-1)
+      fail("refcounting null works incorrectly");
+    json_incref(value);
+    if(value->refcount != (unsigned int)-1)
+      fail("refcounting null works incorrectly");
+
     return 0;
 }