Bug 1365346 - Make Debugger.Source.prototype.sourceMapURL setter check its argc. r=shu

js/src/jit-test/tests/debug/setter-argc.js

@@ -0,0 +1,52 @@
+// Check that setters throw TypeError when passed no arguments, instead of crashing.
+
+function check(obj) {
+  let proto = Object.getPrototypeOf(obj);
+  let props = Object.getOwnPropertyNames(proto);
+  for (let prop of props) {
+    let desc = Object.getOwnPropertyDescriptor(proto, prop);
+    if (desc.set) {
+      print("bleah: " + uneval(prop));
+      assertEq(typeof desc.set, 'function');
+      try {
+        desc.set.call(obj);
+        assertEq("should have thrown TypeError", false);
+      } catch (e) {
+        assertEq(e instanceof TypeError, true);
+      }
+    }
+  }
+}
+
+var dbg = new Debugger;
+var g = newGlobal();
+var gw = dbg.addDebuggee(g);
+
+// Debugger
+check(dbg);
+
+// Debugger.Memory
+check(dbg.memory);
+
+// Debugger.Object
+g.eval('function f() { debugger; }');
+var fw = gw.getOwnPropertyDescriptor('f').value;
+check(fw);
+
+// Debugger.Script
+check(fw.script);
+
+// Debugger.Source
+check(fw.script.source);
+
+// Debugger.Environment
+check(fw.environment);
+
+// Debugger.Frame
+var log = '';
+dbg.onDebuggerStatement = function(frame) {
+  log += 'd';
+  check(frame);
+}
+g.eval('f()');
+assertEq(log, 'd');

js/src/vm/Debugger.cpp

@@ -7641,9 +7641,11 @@ DebuggerSource_getIntroductionType(JSContext* cx, unsigned argc, Value* vp)
 static bool
 DebuggerSource_setSourceMapURL(JSContext* cx, unsigned argc, Value* vp)
 {
-    THIS_DEBUGSOURCE_SOURCE(cx, argc, vp, "sourceMapURL", args, obj, sourceObject);
+    THIS_DEBUGSOURCE_SOURCE(cx, argc, vp, "set sourceMapURL", args, obj, sourceObject);
     ScriptSource* ss = sourceObject->source();
     MOZ_ASSERT(ss);
+    if (!args.requireAtLeast(cx, "set sourceMapURL", 1))
+        return false;
 
     JSString* str = ToString<CanGC>(cx, args[0]);
     if (!str)