Change shift expressions to unsigned types. Shifting signed values to

a result that is not representable has undefined behaviour.

code/client/cl_main.c

@@ -1539,7 +1539,7 @@ void CL_RequestMotd( void ) {
 	
 	info[0] = 0;
 
-	Com_sprintf( cls.updateChallenge, sizeof( cls.updateChallenge ), "%i", ((rand() << 16) ^ rand()) ^ Com_Milliseconds());
+	Com_sprintf( cls.updateChallenge, sizeof( cls.updateChallenge ), "%i", (int)((((unsigned int)rand() << 16) ^ (unsigned int)rand()) ^ Com_Milliseconds()));
 
 	Info_SetValueForKey( info, "challenge", cls.updateChallenge );
 	Info_SetValueForKey( info, "renderer", cls.glconfig.renderer_string );
@@ -1768,7 +1768,7 @@ void CL_Connect_f( void ) {
 		clc.state = CA_CONNECTING;
 		
 		// Set a client challenge number that ideally is mirrored back by the server.
-		clc.challenge = ((rand() << 16) ^ rand()) ^ Com_Milliseconds();
+		clc.challenge = (((unsigned int)rand() << 16) ^ (unsigned int)rand()) ^ Com_Milliseconds();
 	}
 
 	Key_SetCatcher( 0 );

code/qcommon/md4.c

@@ -106,8 +106,11 @@ static void copy64(uint32_t *M, byte *in)
 	int i;
 
 	for (i=0;i<16;i++)
-		M[i] = (in[i*4+3]<<24) | (in[i*4+2]<<16) |
-			(in[i*4+1]<<8) | (in[i*4+0]<<0);
+		M[i] =
+			((uint32_t)in[i*4+3] << 24) |
+			((uint32_t)in[i*4+2] << 16) |
+			((uint32_t)in[i*4+1] <<	 8) |
+			((uint32_t)in[i*4+0] <<	 0) ;
 }
 
 static void copy4(byte *out,uint32_t x)

code/qcommon/net_chan.c

@@ -52,7 +52,7 @@ to the new value before sending out any replies.
 #define	FRAGMENT_SIZE			(MAX_PACKETLEN - 100)
 #define	PACKET_HEADER			10			// two ints and a short
 
-#define	FRAGMENT_BIT	(1<<31)
+#define	FRAGMENT_BIT	(1U<<31)
 
 cvar_t		*showpackets;
 cvar_t		*showdrop;

code/qcommon/vm_x86.c

@@ -103,7 +103,7 @@ static int isu8(uint32_t v)
 
 static int NextConstant4(void)
 {
-	return (code[pc] | (code[pc+1]<<8) | (code[pc+2]<<16) | (code[pc+3]<<24));
+	return ((unsigned int)code[pc] | ((unsigned int)code[pc+1]<<8) | ((unsigned int)code[pc+2]<<16) | ((unsigned int)code[pc+3]<<24));
 }
 
 static int	Constant4( void ) {

code/server/sv_client.c

@@ -140,7 +140,7 @@ void SV_GetChallenge(netadr_t from)
 	}
 
 	// always generate a new challenge number, so the client cannot circumvent sv_maxping
-	challenge->challenge = ( (rand() << 16) ^ rand() ) ^ svs.time;
+	challenge->challenge = ( ((unsigned int)rand() << 16) ^ (unsigned int)rand() ) ^ svs.time;
 	challenge->wasrefused = qfalse;
 	challenge->time = svs.time;
 

code/server/sv_init.c

@@ -468,7 +468,7 @@ void SV_SpawnServer( char *server, qboolean killBots ) {
 	Cvar_Set("cl_paused", "0");
 
 	// get a new checksum feed and restart the file system
-	sv.checksumFeed = ( ((int) rand() << 16) ^ rand() ) ^ Com_Milliseconds();
+	sv.checksumFeed = ( ((unsigned int)rand() << 16) ^ (unsigned int)rand() ) ^ Com_Milliseconds();
 	FS_Restart( sv.checksumFeed );
 
 	CM_LoadMap( va("maps/%s.bsp", server), qfalse, &checksum );