[#17] Fix context properties when value is null.

Thanks to Spahl for the report, patch, and test, and general awesomeness
at being so thorough.

[#17 state:resolved]

Author: davisp

THANKS

@@ -15,6 +15,7 @@ sk89q
 spahl
     * Heads up on the signal hack and fix for a compiler warning.
     * Bug #16 integer property lookup failure report and fix.
+    * Bug #17 add_property segfault when value is null.
 
 Mike West
     * Reported bug in Context.max_time

spidermonkey/context.c

@@ -18,7 +18,7 @@ add_prop(JSContext* jscx, JSObject* jsobj, jsval key, jsval* rval)
 {
     JSObject* obj = NULL;
 
-    if(!JSVAL_IS_OBJECT(*rval)) return JS_TRUE;
+    if(JSVAL_IS_NULL(*rval) || !JSVAL_IS_OBJECT(*rval)) return JS_TRUE;
 
     obj = JSVAL_TO_OBJECT(*rval);
     if(JS_ObjectIsFunction(jscx, obj)) return set_prop(jscx, jsobj, key, rval);

tests/test-context.py

@@ -27,6 +27,11 @@ def test_reentry(cx):
     cx.execute("var x = 42;")
     t.eq(cx.execute("x;"), 42)
 
+@t.cx()
+def test_null(cx):
+    cx.execute("x = null;")
+    t.eq(cx.execute("x;"), None)
+
 @t.cx()
 def test_get_set_limits(cx):
     t.eq(cx.max_time(), 0)