From cd22c4371f647ccf77484d0e4520c8d7435e710d Mon Sep 17 00:00:00 2001
From: "brendan%mozilla.org" <brendan%mozilla.org>
Date: Sat, 2 Sep 2006 20:33:42 +0000
Subject: [PATCH] Fix local function shadowing argument decompilation (351116,
 r=mrbkap).

---
 js/src/jsopcode.c |  7 +++++--
 js/src/jsparse.c  | 22 +++++++++++++++++-----
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/js/src/jsopcode.c b/js/src/jsopcode.c
index 0cc664fc1939..810856c3e126 100644
--- a/js/src/jsopcode.c
+++ b/js/src/jsopcode.c
@@ -3224,6 +3224,8 @@ js_DecompileFunction(JSPrinter *jp, JSFunction *fun)
     js_puts(jp, "(");
 
     if (FUN_INTERPRETED(fun) && fun->object) {
+        size_t paramsize;
+
         /*
          * Print the parameters.
          *
@@ -3237,12 +3239,13 @@ js_DecompileFunction(JSPrinter *jp, JSFunction *fun)
         cx = jp->sprinter.context;
         nargs = fun->nargs;
         mark = JS_ARENA_MARK(&cx->tempPool);
-        JS_ARENA_ALLOCATE_CAST(params, JSAtom **, &cx->tempPool,
-                               nargs * sizeof(JSAtom *));
+        paramsize = nargs * sizeof(JSAtom *);
+        JS_ARENA_ALLOCATE_CAST(params, JSAtom **, &cx->tempPool, paramsize);
         if (!params) {
             JS_ReportOutOfMemory(cx);
             return JS_FALSE;
         }
+        memset(params, 0, paramsize);
         scope = OBJ_SCOPE(fun->object);
         for (sprop = SCOPE_LAST_PROP(scope); sprop; sprop = sprop->parent) {
             if (sprop->getter != js_GetArgument)
diff --git a/js/src/jsparse.c b/js/src/jsparse.c
index 2acb5e043a82..3b52df13b365 100644
--- a/js/src/jsparse.c
+++ b/js/src/jsparse.c
@@ -1103,12 +1103,14 @@ FunctionDef(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc,
          * local variable to bind its name to its value, and not an activation
          * object property (it might also need the activation property, if the
          * outer function contains with statements, e.g., but the stack slot
-         * wins when jsemit.c's LookupArgOrVar can optimize a JSOP_NAME into a
+         * wins when jsemit.c's BindNameToSlot can optimize a JSOP_NAME into a
          * JSOP_GETVAR bytecode).
          */
         if (AT_TOP_LEVEL(tc) && (tc->flags & TCF_IN_FUNCTION)) {
+            JSScopeProperty *sprop;
+
             /*
-             * Define a property on the outer function so that LookupArgOrVar
+             * Define a property on the outer function so that BindNameToSlot
              * can properly optimize accesses.
              */
             JS_ASSERT(OBJ_GET_CLASS(cx, varobj) == &js_FunctionClass);
@@ -1119,16 +1121,26 @@ FunctionDef(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc,
             }
             if (prop)
                 OBJ_DROP_PROPERTY(cx, pobj, prop);
+            sprop = NULL;
             if (!prop ||
                 pobj != varobj ||
-                ((JSScopeProperty *)prop)->getter != js_GetLocalVariable) {
+                (sprop = (JSScopeProperty *)prop,
+                 sprop->getter != js_GetLocalVariable)) {
+                uintN sflags;
+
+                /*
+                 * Use SPROP_IS_DUPLICATE if there is a formal argument of the
+                 * same name, so the decompiler can find the parameter name.
+                 */
+                sflags = (sprop && sprop->getter == js_GetArgument)
+                         ? SPROP_IS_DUPLICATE | SPROP_HAS_SHORTID
+                         : SPROP_HAS_SHORTID;
                 if (!js_AddHiddenProperty(cx, varobj, ATOM_TO_JSID(funAtom),
                                           js_GetLocalVariable,
                                           js_SetLocalVariable,
                                           SPROP_INVALID_SLOT,
                                           JSPROP_PERMANENT | JSPROP_SHARED,
-                                          SPROP_HAS_SHORTID,
-                                          fp->fun->u.i.nvars)) {
+                                          sflags, fp->fun->u.i.nvars)) {
                     return NULL;
                 }
                 if (fp->fun->u.i.nvars == JS_BITMASK(16)) {