Fixed bug where bad UTF strings might crash the client

Author: nickgammon

ProcessPreviousLine.cpp

@@ -555,8 +555,9 @@ assemble the full text of the original line.
   // check for bad UTF8 in the line - otherwise all triggers will fail
   if (m_bUTF_8)
     {
+    int erroroffset;
     iBad = _pcre_valid_utf8 ((const unsigned char *) (const char *) strCurrentLine, 
-                             strCurrentLine.GetLength ());
+                             strCurrentLine.GetLength (), &erroroffset);
     if (iBad > 0)
       {
        m_iUTF8ErrorCount++;

Utilities.cpp

@@ -2865,9 +2865,9 @@ int UMessageBox (const char * sText, UINT nType, const char * sTitle)
 
   // convert message text to Unicode
 
-  iBad = _pcre_valid_utf8 ((unsigned char  *) sText, strlen (sText));
-
   // use PCRE to validate the string first - if bad, fall back to standard box
+  int erroroffset;
+  iBad = _pcre_valid_utf8 ((unsigned char  *) sText, strlen (sText), &erroroffset);
   if (iBad > 0)
     return ::AfxMessageBox (sText, nType);
 
@@ -2886,7 +2886,7 @@ int UMessageBox (const char * sText, UINT nType, const char * sTitle)
 
   // now do title
 
-  iBad = _pcre_valid_utf8 ((unsigned char  *) sTitle, strlen (sTitle));
+  iBad = _pcre_valid_utf8 ((unsigned char  *) sTitle, strlen (sTitle), &erroroffset);
 
   // use PCRE to validate the title next - if bad, use "MUSHclient" title
   if (iBad > 0)

install/readme.txt

@@ -1,7 +1,7 @@
 MUSHclient version 4.80
 =======================
 
-Thursday, 20th October 2011
+Thursday, 10th December 2011
 
 Author: Nick Gammon
 Web support: http://www.gammon.com.au/forum/

miniwindow.cpp

@@ -763,7 +763,8 @@ void CMiniWindow::FontList (VARIANT & vaResult)
 static long CalculateUTF8length (LPCTSTR Text, size_t length)
   {
 
-  int iBad = _pcre_valid_utf8 ((unsigned char  *) Text, length);
+  int erroroffset;
+  int iBad = _pcre_valid_utf8 ((unsigned char  *) Text, length, &erroroffset);
   if (iBad > 0)
     return -1;
 

scripting/lua_utils.cpp

@@ -1346,12 +1346,13 @@ size_t length;
   // argument is string to be checked
 const char * data = luaL_checklstring (L, 1, &length);
 
-  int iBad = _pcre_valid_utf8 ((unsigned char  *) data, length);
+  int erroroffset;
+  int iBad = _pcre_valid_utf8 ((unsigned char  *) data, length, &erroroffset);
 
   if (iBad > 0)
     {
     lua_pushnil (L);
-    lua_pushnumber (L, iBad + 1);
+    lua_pushnumber (L, erroroffset + 1);
     return 2;  /* return nil and the offset */
     }
 
@@ -1391,12 +1392,13 @@ static int utf8sub (lua_State *L) {
 
   // validate
 
-  int iBad = _pcre_valid_utf8 ((unsigned char  *) s, length);
+  int erroroffset;
+  int iBad = _pcre_valid_utf8 ((unsigned char  *) s, length, &erroroffset);
 
   if (iBad > 0)
     {
     lua_pushnil (L);
-    lua_pushnumber (L, iBad + 1);
+    lua_pushnumber (L, erroroffset + 1);
     return 2;  /* return nil and the offset */
     }
 

stdafx.h

@@ -801,7 +801,7 @@ extern "C"
 
 // stuff we borrow from PCRE
 
-extern "C" int _pcre_valid_utf8(const unsigned char  *buf, int length);
+extern "C" int _pcre_valid_utf8(const unsigned char  *buf, int length, int * erroroffset);
 extern "C" int _pcre_ord2utf8(int cvalue, unsigned char *buffer);
 extern "C" const unsigned char _pcre_utf8_table4[];