diff --git a/mozilla/js/src/jsfun.c b/mozilla/js/src/jsfun.c
index 384ad28d805..fe15a9677b2 100644
--- a/mozilla/js/src/jsfun.c
+++ b/mozilla/js/src/jsfun.c
@@ -1082,7 +1082,6 @@ fun_xdrObject(JSXDRState *xdr, JSObject **objp)
     JSString *atomstr;
     char *propname;
     JSScopeProperty *sprop;
-    JSBool magic;
     jsid propid;
     JSAtom *atom;
     uintN i;
@@ -1185,10 +1184,9 @@ fun_xdrObject(JSXDRState *xdr, JSObject **objp)
             }
         }
     }
-    if (!js_XDRScript(xdr, &fun->script, &magic) ||
-        !magic) {
+
+    if (!js_XDRScript(xdr, &fun->script, NULL))
         return JS_FALSE;
-    }
 
     if (xdr->mode == JSXDR_DECODE) {
         *objp = fun->object;
@@ -1204,6 +1202,8 @@ fun_xdrObject(JSXDRState *xdr, JSObject **objp)
                 return JS_FALSE;
             }
         }
+
+        js_CallNewScriptHook(cx, fun->script, fun);
     }
 
     return JS_TRUE;
diff --git a/mozilla/js/src/jsscript.c b/mozilla/js/src/jsscript.c
index 1555af35086..1f5056309ea 100644
--- a/mozilla/js/src/jsscript.c
+++ b/mozilla/js/src/jsscript.c
@@ -350,16 +350,22 @@ js_XDRScript(JSXDRState *xdr, JSScript **scriptp, JSBool *hasMagic)
     if (magic != JSXDR_MAGIC_SCRIPT_3 &&
         magic != JSXDR_MAGIC_SCRIPT_2 &&
         magic != JSXDR_MAGIC_SCRIPT_1) {
+        if (!hasMagic) {
+            JS_ReportErrorNumber(xdr->cx, js_GetErrorMessage, NULL,
+                                 JSMSG_BAD_SCRIPT_MAGIC);
+            return JS_FALSE;
+        }
         *hasMagic = JS_FALSE;
         return JS_TRUE;
     }
-    *hasMagic = JS_TRUE;
+    if (hasMagic)
+        *hasMagic = JS_TRUE;
 
     if (xdr->mode == JSXDR_ENCODE) {
         jssrcnote *sn = script->notes;
         length = script->length;
         prologLength = script->main - script->code;
-        version = (int32) script->version;
+        version = (int32)script->version;
         lineno = (uint32)script->lineno;
         depth = (uint32)script->depth;
 
@@ -397,6 +403,7 @@ js_XDRScript(JSXDRState *xdr, JSScript **scriptp, JSBool *hasMagic)
         *scriptp = script;
     }
 
+    /* Control hereafter must goto error on failure, to destroy script. */
     if (!JS_XDRBytes(xdr, (char **)&script->code, length) ||
         !XDRAtomMap(xdr, &script->atomMap) ||
         !JS_XDRUint32(xdr, &notelen) ||
@@ -607,6 +614,7 @@ script_thaw(JSContext *cx, JSObject *obj, uintN argc, jsval *argv,
         js_DestroyScript(cx, oldscript);
 
     script->object = obj;
+    js_CallNewScriptHook(cx, script, NULL);
 
 out:
     /*
@@ -785,8 +793,6 @@ js_NewScriptFromCG(JSContext *cx, JSCodeGenerator *cg, JSFunction *fun)
     JSTryNote *trynotes;
     jssrcnote *notes;
     JSScript *script;
-    JSRuntime *rt;
-    JSNewScriptHook hook;
 
     if (!js_FinishTakingTryNotes(cx, cg, &trynotes))
         return NULL;
@@ -804,6 +810,16 @@ js_NewScriptFromCG(JSContext *cx, JSCodeGenerator *cg, JSFunction *fun)
     }
 
     /* Tell the debugger about this compiled script. */
+    js_CallNewScriptHook(cx, script, fun);
+    return script;
+}
+
+JS_FRIEND_API(void)
+js_CallNewScriptHook(JSContext *cx, JSScript *script, JSFunction *fun)
+{
+    JSRuntime *rt;
+    JSNewScriptHook hook;
+
     rt = cx->runtime;
     hook = rt->newScriptHook;
     if (hook) {
@@ -822,12 +838,11 @@ js_NewScriptFromCG(JSContext *cx, JSCodeGenerator *cg, JSFunction *fun)
         dummy.script = script;
         cx->fp = &dummy;
 
-        (*hook)(cx, cg->filename, cg->firstLine, script, fun,
-                rt->newScriptHookData);
+        hook(cx, script->filename, script->lineno, script, fun,
+             rt->newScriptHookData);
 
         cx->fp = dummy.down;
     }
-    return script;
 }
 
 void
diff --git a/mozilla/js/src/jsscript.h b/mozilla/js/src/jsscript.h
index c2881f1da28..15e2ee79b36 100644
--- a/mozilla/js/src/jsscript.h
+++ b/mozilla/js/src/jsscript.h
@@ -89,6 +89,17 @@ extern JS_FRIEND_DATA(JSClass) js_ScriptClass;
 extern JSObject *
 js_InitScriptClass(JSContext *cx, JSObject *obj);
 
+/*
+ * Three successively less primitive ways to make a new JSScript.  The first
+ * two do *not* call a non-null cx->runtime->newScriptHook -- only the last,
+ * js_NewScriptFromCG, calls this optional debugger hook.
+ *
+ * The js_NewScript function can't know whether the script it creates belongs
+ * to a function, or is top-level or eval code, but the debugger wants access
+ * to the newly made script's function, if any -- so callers of js_NewScript
+ * are responsible for notifying the debugger after successfully creating any
+ * kind (function or other) of new JSScript.
+ */
 extern JSScript *
 js_NewScript(JSContext *cx, uint32 length);
 
@@ -102,6 +113,15 @@ js_NewScriptFromParams(JSContext *cx, jsbytecode *code, uint32 length,
 extern JS_FRIEND_API(JSScript *)
 js_NewScriptFromCG(JSContext *cx, JSCodeGenerator *cg, JSFunction *fun);
 
+/*
+ * New-script-hook calling is factored from js_NewScriptFromCG so that it
+ * and callers of js_XDRScript can share this code.  In the case of callers
+ * of js_XDRScript, the hook should be invoked only after successful decode
+ * of any owning function (the fun parameter) or script object (null fun).
+ */
+extern JS_FRIEND_API(void)
+js_CallNewScriptHook(JSContext *cx, JSScript *script, JSFunction *fun);
+
 extern void
 js_DestroyScript(JSContext *cx, JSScript *script);
 
@@ -120,6 +140,15 @@ js_LineNumberToPC(JSScript *script, uintN lineno);
 extern uintN
 js_GetScriptLineExtent(JSScript *script);
 
+/*
+ * If magic is non-null, js_XDRScript succeeds on magic number mismatch but
+ * returns false in *magic; it reflects a match via a true *magic out param.
+ * If magic is null, js_XDRScript returns false on bad magic number errors,
+ * which it reports.
+ *
+ * NB: callers must call js_CallNewScriptHook after successful JSXDR_DECODE
+ * and subsequent set-up of owning function or script object, if any.
+ */
 extern JSBool
 js_XDRScript(JSXDRState *xdr, JSScript **scriptp, JSBool *magic);
 
diff --git a/mozilla/js/src/jsxdrapi.c b/mozilla/js/src/jsxdrapi.c
index fa434576ffa..c8172cc9abb 100644
--- a/mozilla/js/src/jsxdrapi.c
+++ b/mozilla/js/src/jsxdrapi.c
@@ -574,15 +574,10 @@ JS_XDRValue(JSXDRState *xdr, jsval *vp)
 JS_PUBLIC_API(JSBool)
 JS_XDRScript(JSXDRState *xdr, JSScript **scriptp)
 {
-    JSBool hasMagic;
-
-    if (!js_XDRScript(xdr, scriptp, &hasMagic))
+    if (!js_XDRScript(xdr, scriptp, NULL))
         return JS_FALSE;
-    if (!hasMagic) {
-        JS_ReportErrorNumber(xdr->cx, js_GetErrorMessage, NULL,
-                             JSMSG_BAD_SCRIPT_MAGIC);
-        return JS_FALSE;
-    }
+    if (xdr->mode == JSXDR_DECODE)
+        js_CallNewScriptHook(xdr->cx, *scriptp, NULL);
     return JS_TRUE;
 }