* (bug 3019) adds the cvar cl_guidServerUniq (defaults to 1). When set to

non-zero, cl_guid will be unique for each server that the client
  connects to

code/client/cl_main.c

@@ -74,6 +74,8 @@ cvar_t	*cl_trn;
 
 cvar_t	*cl_lanForcePackets;
 
+cvar_t	*cl_guidServerUniq;
+
 clientActive_t		cl;
 clientConnection_t	clc;
 clientStatic_t		cls;
@@ -713,6 +715,28 @@ void CL_ClearState (void) {
 	Com_Memset( &cl, 0, sizeof( cl ) );
 }
 
+/*
+====================
+CL_UpdateGUID
+
+update cl_guid using QKEY_FILE and optional prefix
+====================
+*/
+static void CL_UpdateGUID( char *prefix, int prefix_len )
+{
+	fileHandle_t f;
+	int len;
+
+	len = FS_SV_FOpenFileRead( QKEY_FILE, &f );
+	FS_FCloseFile( f );
+
+	if( len != QKEY_SIZE ) 
+		Cvar_Set( "cl_guid", "" );
+	else
+		Cvar_Set( "cl_guid", Com_MD5File( QKEY_FILE, QKEY_SIZE,
+			prefix, prefix_len ) );
+}
+
 
 /*
 =====================
@@ -781,6 +805,7 @@ void CL_Disconnect( qboolean showMainMenu ) {
 	if( CL_VideoRecording( ) ) {
 		CL_CloseAVI( );
 	}
+	CL_UpdateGUID( NULL, 0 );
 }
 
 
@@ -1036,6 +1061,7 @@ CL_Connect_f
 */
 void CL_Connect_f( void ) {
 	char	*server;
+	char	serverString[ 22 ];
 
 	if ( Cmd_Argc() != 2 ) {
 		Com_Printf( "usage: connect [server]\n");
@@ -1078,11 +1104,18 @@ void CL_Connect_f( void ) {
 	if (clc.serverAddress.port == 0) {
 		clc.serverAddress.port = BigShort( PORT_SERVER );
 	}
-	Com_Printf( "%s resolved to %i.%i.%i.%i:%i\n", cls.servername,
+	Com_sprintf( serverString, sizeof( serverString ), "%i.%i.%i.%i:%i",
                 clc.serverAddress.ip[0], clc.serverAddress.ip[1],
                 clc.serverAddress.ip[2], clc.serverAddress.ip[3],
                 BigShort( clc.serverAddress.port ) );
  
+	Com_Printf( "%s resolved to %s\n", cls.servername, serverString );
+
+	if( cl_guidServerUniq->integer )
+		CL_UpdateGUID( serverString, strlen( serverString ) );
+	else
+		CL_UpdateGUID( NULL, 0 );
+
 	// if we aren't playing on a lan, we need to authenticate
 	// with the cd key
 	if ( NET_IsLocalAddress( clc.serverAddress ) ) {
@@ -2480,25 +2513,48 @@ void CL_StopVideo_f( void )
   CL_CloseAVI( );
 }
 
+/*
+===============
+CL_GenerateQKey
+
+test to see if a valid QKEY_FILE exists.  If one does not, try to generate
+it by filling it with 2048 bytes of random data.
+===============
+*/
 static void CL_GenerateQKey(void)
 {
 	int len = 0;
-	unsigned char buff[2048];
+	unsigned char buff[ QKEY_SIZE ];
+	fileHandle_t f;
 
-	len = FS_ReadFile(QKEY_FILE, NULL);
+	len = FS_SV_FOpenFileRead( QKEY_FILE, &f );
-	if(len >= (int)sizeof(buff)) {
+	FS_FCloseFile( f );
+	if( len == QKEY_SIZE ) {
 		Com_Printf( "QKEY found.\n" );
 		return;
 	}
 	else {
 		int i;
+
+		if( len > 0 ) {
+			Com_Printf( "QKEY file size != %d, regenerating\n",
+				QKEY_SIZE );
+		}
+
 		srand(time(0));
 		for(i = 0; i < sizeof(buff) - 1; i++) {
 			buff[i] = (unsigned char)(rand() % 255);
 		}
 		buff[i] = 0;
+		f = FS_SV_FOpenFileWrite( QKEY_FILE );
+		if( !f ) {
+			Com_Printf( "QKEY could not open %s for write\n",
+				QKEY_FILE );
+			return;
+		}
+		FS_Write( buff, sizeof(buff), f );
+		FS_FCloseFile( f );
 		Com_Printf( "QKEY generated\n" );
-		FS_WriteFile(QKEY_FILE, buff, sizeof(buff));
 	}
 } 
 
@@ -2595,6 +2651,8 @@ void CL_Init( void ) {
 
 	cl_lanForcePackets = Cvar_Get ("cl_lanForcePackets", "1", CVAR_ARCHIVE);
 
+	cl_guidServerUniq = Cvar_Get ("cl_guidServerUniq", "1", CVAR_ARCHIVE);
+
 	// userinfo
 	Cvar_Get ("name", "UnnamedPlayer", CVAR_USERINFO | CVAR_ARCHIVE );
 	Cvar_Get ("rate", "3000", CVAR_USERINFO | CVAR_ARCHIVE );
@@ -2655,7 +2713,8 @@ void CL_Init( void ) {
 	Cvar_Set( "cl_running", "1" );
 
 	CL_GenerateQKey();	
-	Cvar_Get("cl_guid", Com_MD5File(QKEY_FILE, 0), CVAR_USERINFO | CVAR_ROM);
+	Cvar_Get( "cl_guid", "", CVAR_USERINFO | CVAR_ROM );
+	CL_UpdateGUID( NULL, 0 );
 
 	Com_Printf( "----- Client Initialization Complete -----\n" );
 }

code/client/client.h

@@ -34,8 +34,9 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "cl_curl.h"
 #endif /* USE_CURL */
 
-// tjw: file full of random crap that gets used to create cl_guid
+// file full of random crap that gets used to create cl_guid
 #define QKEY_FILE "qkey"
+#define QKEY_SIZE 2048
 
 #define	RETRANSMIT_TIMEOUT	3000	// time between connection packet retransmits
 

code/qcommon/md5.c

@@ -257,9 +257,9 @@ static void MD5Final(struct MD5Context *ctx, unsigned char *digest)
 }
 
 
-char *Com_MD5File(const char *fn, int length)
+char *Com_MD5File( const char *fn, int length, const char *prefix, int prefix_len )
 {
-	static char final[33] = {"unknown"};
+	static char final[33] = {""};
 	unsigned char digest[16] = {""}; 
 	fileHandle_t f;
 	MD5_CTX md5;
@@ -269,8 +269,15 @@ char *Com_MD5File(const char *fn, int length)
 	int r = 0;
 	int total = 0;
 
-	filelen = FS_FOpenFileRead(fn, &f, qtrue);
+	Q_strncpyz( final, "", sizeof( final ) );
+
+	filelen = FS_SV_FOpenFileRead( fn, &f );
+
+	if( !f ) {
+		return final;
+	}
 	if( filelen < 1 ) {
+		FS_FCloseFile( f );
 		return final;
 	}
 	if(filelen < length || !length) {
@@ -278,6 +285,10 @@ char *Com_MD5File(const char *fn, int length)
 	}
 
 	MD5Init(&md5);
+
+	if( prefix_len && *prefix )
+		MD5Update(&md5 , (unsigned char *)prefix, prefix_len);
+
 	for(;;) {
 		r = FS_Read2(buffer, sizeof(buffer), f);
 		if(r < 1)

code/qcommon/qcommon.h

@@ -732,7 +732,7 @@ void 		Com_Quit_f( void );
 int			Com_EventLoop( void );
 int			Com_Milliseconds( void );	// will be journaled properly
 unsigned	Com_BlockChecksum( const void *buffer, int length );
-char		*Com_MD5File(const char *filename, int length);
+char		*Com_MD5File(const char *filename, int length, const char *prefix, int prefix_len);
 int			Com_HashKey(char *string, int maxlen);
 int			Com_Filter(char *filter, char *name, int casesensitive);
 int			Com_FilterPath(char *filter, char *name, int casesensitive);