From 467e6b2b97f496a33fc2908e18a420330226503e Mon Sep 17 00:00:00 2001
From: "darin%meer.net" <darin%meer.net@18797224-902f-48f8-a5cc-f745e15eee43>
Date: Fri, 7 Oct 2005 21:52:18 +0000
Subject: [PATCH] fixes bug 311456 "Calling Truncate() on an nsAutoString makes
 next append work hard" r+sr=bzbarsky

git-svn-id: svn://10.0.0.236/trunk@181788 18797224-902f-48f8-a5cc-f745e15eee43
---
 mozilla/xpcom/string/src/nsTSubstring.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mozilla/xpcom/string/src/nsTSubstring.cpp b/mozilla/xpcom/string/src/nsTSubstring.cpp
index 1eb89b2de3b..bee1873f554 100644
--- a/mozilla/xpcom/string/src/nsTSubstring.cpp
+++ b/mozilla/xpcom/string/src/nsTSubstring.cpp
@@ -542,6 +542,9 @@ nsTSubstring_CharT::SetCapacity( size_type capacity )
 void
 nsTSubstring_CharT::SetLength( size_type length )
   {
+    if (mLength == length)
+      return;
+
     SetCapacity(length);
 
     // XXX(darin): SetCapacity may fail, but it doesn't give us a way to find