From d502903332ec7c95aa22652cb4320df4726e6d13 Mon Sep 17 00:00:00 2001
From: "bzbarsky%mit.edu"
 <bzbarsky%mit.edu@18797224-902f-48f8-a5cc-f745e15eee43>
Date: Tue, 8 Jun 2004 18:54:57 +0000
Subject: [PATCH] Make the scanner bail out of functions that assume it's
 initialized if mSlidingBuffer is null.  Bug 108067, patch by Andreas M.
 "Clarence" Schneider <c@c07.de> and Blake Kaplan <mrbkap@rice.edu>,
 r+sr=bzbarsky

git-svn-id: svn://10.0.0.236/trunk@157598 18797224-902f-48f8-a5cc-f745e15eee43
---
 mozilla/parser/htmlparser/src/nsScanner.cpp | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/mozilla/parser/htmlparser/src/nsScanner.cpp b/mozilla/parser/htmlparser/src/nsScanner.cpp
index cf515ac2606..39958e38916 100644
--- a/mozilla/parser/htmlparser/src/nsScanner.cpp
+++ b/mozilla/parser/htmlparser/src/nsScanner.cpp
@@ -266,8 +266,10 @@ nsScanner::~nsScanner() {
  *  @return  
  */
 void nsScanner::RewindToMark(void){
-  mCountRemaining += (Distance(mMarkPosition, mCurrentPosition));
-  mCurrentPosition = mMarkPosition;
+  if (mSlidingBuffer) {
+    mCountRemaining += (Distance(mMarkPosition, mCurrentPosition));
+    mCurrentPosition = mMarkPosition;
+  }
 }
 
 
@@ -297,6 +299,9 @@ void nsScanner::Mark() {
  * @return  error code 
  */
 PRBool nsScanner::UngetReadable(const nsAString& aBuffer) {
+  if (!mSlidingBuffer) {
+    return PR_FALSE;
+  }
 
   mSlidingBuffer->UngetReadable(aBuffer,mCurrentPosition);
   mSlidingBuffer->BeginReading(mCurrentPosition); // Insertion invalidated our iterators
@@ -316,7 +321,6 @@ PRBool nsScanner::UngetReadable(const nsAString& aBuffer) {
  * @return  error code 
  */
 nsresult nsScanner::Append(const nsAString& aBuffer) {
-  
   mTotalRead += aBuffer.Length();
   AppendToBuffer(aBuffer);
   return NS_OK;
@@ -1335,6 +1339,11 @@ void nsScanner::AppendASCIItoBuffer(const char* aData, PRUint32 aLen)
  *  @return  nada
  */
 void nsScanner::CopyUnusedData(nsString& aCopyBuffer) {
+  if (!mSlidingBuffer) {
+    aCopyBuffer.Truncate();
+    return;
+  }
+
   nsScannerIterator start, end;
   start = mCurrentPosition;
   end = mEndPosition;