Bug 353116 - ""has no properties" is misleading and should be replaced with "is null or undefined"" [p=rich@rd.gen.nz (Rich Dougherty) r=brendan r=crowder a1.9=damons]

js/src/js.msg

@@ -301,3 +301,4 @@ MSG_DEF(JSMSG_EMPTY_ARRAY_REDUCE,     218, 0, JSEXN_TYPEERR, "reduce of empty ar
 MSG_DEF(JSMSG_NON_LIST_XML_METHOD,    219, 2, JSEXN_TYPEERR, "cannot call {0} method on an XML list with {1} elements")
 MSG_DEF(JSMSG_BAD_DELETE_OPERAND,     220, 0, JSEXN_SYNTAXERR, "invalid delete operand")
 MSG_DEF(JSMSG_BAD_INCOP_OPERAND,      221, 0, JSEXN_SYNTAXERR, "invalid increment/decrement operand")
+MSG_DEF(JSMSG_NULL_OR_UNDEFINED,      222, 2, JSEXN_TYPEERR, "{0} is {1}")

js/src/jscntxt.c

@@ -1218,6 +1218,40 @@ js_ReportIsNotDefined(JSContext *cx, const char *name)
     JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_NOT_DEFINED, name);
 }
 
+JSBool
+js_ReportIsNullOrUndefined(JSContext *cx, intN spindex, jsval v,
+                           JSString *fallback)
+{
+    char *bytes;
+    JSBool ok;
+
+    bytes = js_DecompileValueGenerator(cx, spindex, v, fallback);
+    if (!bytes)
+        return JS_FALSE;
+
+    if (strcmp(bytes, js_undefined_str) == 0 ||
+        strcmp(bytes, js_null_str) == 0) {
+        ok = JS_ReportErrorFlagsAndNumber(cx, JSREPORT_ERROR,
+                                          js_GetErrorMessage, NULL,
+                                          JSMSG_NO_PROPERTIES, bytes,
+                                          NULL, NULL);
+    } else if (JSVAL_IS_VOID(v)) {
+        ok = JS_ReportErrorFlagsAndNumber(cx, JSREPORT_ERROR,
+                                          js_GetErrorMessage, NULL,
+                                          JSMSG_NULL_OR_UNDEFINED, bytes,
+                                          js_undefined_str, NULL);
+    } else {
+        JS_ASSERT(JSVAL_IS_NULL(v));
+        ok = JS_ReportErrorFlagsAndNumber(cx, JSREPORT_ERROR,
+                                          js_GetErrorMessage, NULL,
+                                          JSMSG_NULL_OR_UNDEFINED, bytes,
+                                          js_null_str, NULL);
+    }
+
+    JS_free(cx, bytes);
+    return ok;
+}
+
 JSBool
 js_ReportValueErrorFlags(JSContext *cx, uintN flags, const uintN errorNumber,
                          intN spindex, jsval v, JSString *fallback,

js/src/jscntxt.h

@@ -977,6 +977,13 @@ js_ReportErrorAgain(JSContext *cx, const char *message, JSErrorReport *report);
 extern void
 js_ReportIsNotDefined(JSContext *cx, const char *name);
 
+/*
+ * Report an attempt to access the property of a null or undefined value (v).
+ */
+extern JSBool
+js_ReportIsNullOrUndefined(JSContext *cx, intN spindex, jsval v,
+                           JSString *fallback);
+
 /*
  * Report error using js_DecompileValueGenerator(cx, spindex, v, fallback) as
  * the first argument for the error message. If the error message has less

js/src/jsinterp.c

@@ -5852,8 +5852,7 @@ interrupt:
                     i = JSProto_Boolean;
                 } else {
                     JS_ASSERT(JSVAL_IS_NULL(lval) || JSVAL_IS_VOID(lval));
-                    js_ReportValueError(cx, JSMSG_NO_PROPERTIES, -2, lval,
-                                        NULL);
+                    js_ReportIsNullOrUndefined(cx, -2, lval, NULL);
                     ok = JS_FALSE;
                     goto out;
                 }

js/src/jsobj.c

@@ -4651,10 +4651,8 @@ js_ValueToNonNullObject(JSContext *cx, jsval v)
 
     if (!js_ValueToObject(cx, v, &obj))
         return NULL;
-    if (!obj) {
-        js_ReportValueError(cx, JSMSG_NO_PROPERTIES,
-                            JSDVG_SEARCH_STACK, v, NULL);
-    }
+    if (!obj)
+        js_ReportIsNullOrUndefined(cx, JSDVG_SEARCH_STACK, v, NULL);
     return obj;
 }