From 20eca7a69e334180bb5e3a9e621583de59284331 Mon Sep 17 00:00:00 2001
From: Michael Wu <mwu@mozilla.com>
Date: Tue, 15 Mar 2011 18:00:58 -0700
Subject: [PATCH] Bug 632253 - Move magic check to JS_XDRScript, r=igor

---
 js/src/jsfun.cpp    |  2 +-
 js/src/jsscript.cpp | 24 +++---------------------
 js/src/jsscript.h   |  7 +------
 js/src/jsxdrapi.cpp | 15 +++++++++++++--
 4 files changed, 18 insertions(+), 30 deletions(-)

diff --git a/js/src/jsfun.cpp b/js/src/jsfun.cpp
index f9fb5e60711e..a8cba532702c 100644
--- a/js/src/jsfun.cpp
+++ b/js/src/jsfun.cpp
@@ -1903,7 +1903,7 @@ js_XDRFunctionObject(JSXDRState *xdr, JSObject **objp)
         fun->u.i.wrapper = JSPackedBool((firstword >> 1) & 1);
     }
 
-    if (!js_XDRScript(xdr, &fun->u.i.script, NULL))
+    if (!js_XDRScript(xdr, &fun->u.i.script))
         return false;
 
     if (xdr->mode == JSXDR_DECODE) {
diff --git a/js/src/jsscript.cpp b/js/src/jsscript.cpp
index b039f52feb3b..d64a08c47afe 100644
--- a/js/src/jsscript.cpp
+++ b/js/src/jsscript.cpp
@@ -308,7 +308,7 @@ enum ScriptBits {
 };
 
 JSBool
-js_XDRScript(JSXDRState *xdr, JSScript **scriptp, JSBool *hasMagic)
+js_XDRScript(JSXDRState *xdr, JSScript **scriptp)
 {
     JSScript *oldscript;
     JSBool ok;
@@ -333,24 +333,6 @@ js_XDRScript(JSXDRState *xdr, JSScript **scriptp, JSBool *hasMagic)
     /* Should not XDR scripts optimized for a single global object. */
     JS_ASSERT_IF(script, !JSScript::isValidOffset(script->globalsOffset));
 
-    uint32 magic;
-    if (xdr->mode == JSXDR_ENCODE)
-        magic = JSXDR_MAGIC_SCRIPT_CURRENT;
-    if (!JS_XDRUint32(xdr, &magic))
-        return JS_FALSE;
-    if (magic != JSXDR_MAGIC_SCRIPT_CURRENT) {
-        /* We do not provide binary compatibility with older scripts. */
-        if (!hasMagic) {
-            JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
-                                 JSMSG_BAD_SCRIPT_MAGIC);
-            return JS_FALSE;
-        }
-        *hasMagic = JS_FALSE;
-        return JS_TRUE;
-    }
-    if (hasMagic)
-        *hasMagic = JS_TRUE;
-
     /* XDR arguments, local vars, and upvars. */
     uint16 nargs, nvars, nupvars;
 #if defined(DEBUG) || defined(__GNUC__) /* quell GCC overwarning */
@@ -1983,7 +1965,7 @@ js_CloneScript(JSContext *cx, JSScript *script)
     // we don't want gecko to transcribe our principals for us
     DisablePrincipalsTranscoding disable(cx);
 
-    if (!js_XDRScript(w, &script, NULL)) {
+    if (!js_XDRScript(w, &script)) {
         JS_XDRDestroy(w);
         return NULL;
     }
@@ -2007,7 +1989,7 @@ js_CloneScript(JSContext *cx, JSScript *script)
     JS_XDRMemSetData(r, p, nbytes);
     JS_XDRMemSetData(w, NULL, 0);
 
-    if (!js_XDRScript(r, &script, NULL))
+    if (!js_XDRScript(r, &script))
         return NULL;
 
     JS_XDRDestroy(r);
diff --git a/js/src/jsscript.h b/js/src/jsscript.h
index 2fc9625b318f..6868868f89d8 100644
--- a/js/src/jsscript.h
+++ b/js/src/jsscript.h
@@ -771,17 +771,12 @@ extern JSScript *
 js_CloneScript(JSContext *cx, 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: after a successful JSXDR_DECODE, js_XDRScript callers must do any
  * required subsequent set-up of owning function or script object and then call
  * js_CallNewScriptHook.
  */
 extern JSBool
-js_XDRScript(JSXDRState *xdr, JSScript **scriptp, JSBool *hasMagic);
+js_XDRScript(JSXDRState *xdr, JSScript **scriptp);
 
 inline bool
 JSObject::isScript() const
diff --git a/js/src/jsxdrapi.cpp b/js/src/jsxdrapi.cpp
index e0fd36c078bf..2fae06a3ccb8 100644
--- a/js/src/jsxdrapi.cpp
+++ b/js/src/jsxdrapi.cpp
@@ -666,14 +666,25 @@ JS_PUBLIC_API(JSBool)
 JS_XDRScriptObject(JSXDRState *xdr, JSObject **scriptObjp)
 {
     JSScript *script;
+    uint32 magic;
     if (xdr->mode == JSXDR_DECODE) {
         script = NULL;
         *scriptObjp = NULL;
     } else {
         script = (*scriptObjp)->getScript();
+        magic = JSXDR_MAGIC_SCRIPT_CURRENT;
     }
-    
-    if (!js_XDRScript(xdr, &script, NULL))
+
+    if (!JS_XDRUint32(xdr, &magic))
+        return false;
+
+    if (magic != JSXDR_MAGIC_SCRIPT_CURRENT) {
+        /* We do not provide binary compatibility with older scripts. */
+        JS_ReportErrorNumber(xdr->cx, js_GetErrorMessage, NULL, JSMSG_BAD_SCRIPT_MAGIC);
+        return false;
+    }
+
+    if (!js_XDRScript(xdr, &script))
         return false;
 
     if (xdr->mode == JSXDR_DECODE) {