fix potential memory trounce when syncing for offline on some imap servers, r=ducarroz, sr=sspitzer 181372

mailnews/imap/src/nsImapFlagAndUidState.cpp

@@ -398,21 +398,12 @@ NS_IMETHODIMP nsImapFlagAndUidState::GetCustomFlags(PRUint32 uid, char **customF
   nsAutoCMonitor(this);
   if (m_customFlagsHash)
   {
-  nsPRUint32Key hashKey(uid);
-  char *value = (char *) m_customFlagsHash->Get(&hashKey);
+    nsPRUint32Key hashKey(uid);
+    char *value = (char *) m_customFlagsHash->Get(&hashKey);
     if (value)
     {
-  PRUint32 valueLen = 0, curStringLen = 0;
-  do 
-  {
-    curStringLen = strlen(value + valueLen) + 1;
-    valueLen += curStringLen;
-  }
-  while (curStringLen > 1);
-
-  *customFlags = (char *) PR_Malloc(valueLen);
-  memcpy(*customFlags, value, valueLen);
-      return NS_OK;
+      *customFlags = nsCRT::strdup(value);
+      return (*customFlags) ? NS_OK : NS_ERROR_FAILURE;
     }
   }
   *customFlags = nsnull;