Bug 1333038 - Use 'modern' pointers to fix crash due to nsMsgLineStreamBuffer object being deleted while still in use.

Suspected "use after free" in nsMsgLineStreamBuffer::ReadNextLine() leading to crash since object may be destroyed while still in use on another thread.

Tag #1273

mailnews/local/src/nsMailboxProtocol.cpp

@@ -50,8 +50,6 @@ PRLogModuleInfo *MAILBOX;
 nsMailboxProtocol::nsMailboxProtocol(nsIURI * aURI)
     : nsMsgProtocol(aURI)
 {
-  m_lineStreamBuffer =nullptr;
-
   // initialize the pr log if it hasn't been initialiezed already
   if (!MAILBOX)
     MAILBOX = PR_NewLogModule("MAILBOX");
@@ -59,8 +57,6 @@ nsMailboxProtocol::nsMailboxProtocol(nsIURI * aURI)
 
 nsMailboxProtocol::~nsMailboxProtocol()
 {
-  // free our local state
-  delete m_lineStreamBuffer;
 }
 
 nsresult nsMailboxProtocol::OpenMultipleMsgTransport(uint64_t offset, int32_t size)

mailnews/local/src/nsMailboxProtocol.h

@@ -74,7 +74,7 @@ private:
   nsCOMPtr<nsIStreamListener> m_mailboxParser;
 
   // Local state for the current operation
-  nsMsgLineStreamBuffer   * m_lineStreamBuffer; // used to efficiently extract lines from the incoming data stream
+  RefPtr<nsMsgLineStreamBuffer> m_lineStreamBuffer; // used to efficiently extract lines from the incoming data stream
 
   // Generic state information -- What state are we in? What state do we want to go to
   // after the next response? What was the last response code? etc.

mailnews/local/src/nsPop3Protocol.cpp

@@ -451,7 +451,6 @@ nsPop3Protocol::nsPop3Protocol(nsIURI* aURL)
   m_totalFolderSize(0),
   m_totalDownloadSize(0),
   m_totalBytesReceived(0),
-  m_lineStreamBuffer(nullptr),
   m_pop3ConData(nullptr)
 {
 }
@@ -590,9 +589,6 @@ void nsPop3Protocol::Cleanup()
   FreeMsgInfo();
   PR_Free(m_pop3ConData->only_uidl);
   PR_Free(m_pop3ConData);
-
-  delete m_lineStreamBuffer;
-  m_lineStreamBuffer = nullptr;
 }
 
 void nsPop3Protocol::SetCapFlag(uint32_t flag)

mailnews/local/src/nsPop3Protocol.h

@@ -318,7 +318,7 @@ private:
   nsCOMPtr<nsIPop3Sink> m_nsIPop3Sink;
   nsCOMPtr<nsIPop3IncomingServer> m_pop3Server;
 
-  nsMsgLineStreamBuffer   * m_lineStreamBuffer; // used to efficiently extract lines from the incoming data stream
+  RefPtr<nsMsgLineStreamBuffer> m_lineStreamBuffer; // used to efficiently extract lines from the incoming data stream
   Pop3ConData* m_pop3ConData;
   void FreeMsgInfo();
   void Abort();