From 39405c94cd09bd3360cb06ecea1e9402e7600b5e Mon Sep 17 00:00:00 2001
From: "bzbarsky%mit.edu"
 <bzbarsky%mit.edu@18797224-902f-48f8-a5cc-f745e15eee43>
Date: Sat, 30 Oct 2004 18:11:25 +0000
Subject: [PATCH] Allow setting the value of <input type="file"> to an empty
 string even in untrusted script.  Bug 266744, r=sicking, sr=jst

git-svn-id: svn://10.0.0.236/trunk@164672 18797224-902f-48f8-a5cc-f745e15eee43
---
 mozilla/content/html/content/src/nsHTMLInputElement.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mozilla/content/html/content/src/nsHTMLInputElement.cpp b/mozilla/content/html/content/src/nsHTMLInputElement.cpp
index b41594e5f51..c3f2def5967 100644
--- a/mozilla/content/html/content/src/nsHTMLInputElement.cpp
+++ b/mozilla/content/html/content/src/nsHTMLInputElement.cpp
@@ -639,8 +639,9 @@ nsHTMLInputElement::GetValue(nsAString& aValue)
 NS_IMETHODIMP 
 nsHTMLInputElement::SetValue(const nsAString& aValue)
 {
-  //check secuity
-  if (mType == NS_FORM_INPUT_FILE) {
+  // check security.  Note that setting the value to the empty string is always
+  // OK and gives pages a way to clear a file input if necessary.
+  if (mType == NS_FORM_INPUT_FILE && !aValue.IsEmpty()) {
     nsIScriptSecurityManager *securityManager =
       nsContentUtils::GetSecurityManager();