Handle ERR_DROP during Com_GameRestart

If ERR_DROP during Com_GameRestart after shutting down client, Com_Error
needs to restart the client otherwise there is just a black window. Also,
clear the game restarting flag in Com_Error otherwise it's not possible to
run Com_GameRestart again later.

I don't know of a way to trigger ERR_DROP, in FS_Restart for instance,
without engine changes however.

code/qcommon/common.c

@@ -115,6 +115,7 @@ int			com_frameNumber;
 qboolean	com_errorEntered = qfalse;
 qboolean	com_fullyInitialized = qfalse;
 qboolean	com_gameRestarting = qfalse;
+qboolean	com_gameClientRestarting = qfalse;
 
 char	com_errorMessage[MAXPRINTMSG];
 
@@ -264,6 +265,7 @@ void QDECL Com_Error( int code, const char *fmt, ... ) {
 	static int	lastErrorTime;
 	static int	errorCount;
 	int			currentTime;
+	qboolean	restartClient;
 
 	if(com_errorEntered)
 		Sys_Error("recursive error after: %s", com_errorMessage);
@@ -296,9 +298,17 @@ void QDECL Com_Error( int code, const char *fmt, ... ) {
 	if (code != ERR_DISCONNECT && code != ERR_NEED_CD)
 		Cvar_Set("com_errorMessage", com_errorMessage);
 
+	restartClient = com_gameClientRestarting && !( com_cl_running && com_cl_running->integer );
+
+	com_gameRestarting = qfalse;
+	com_gameClientRestarting = qfalse;
+
 	if (code == ERR_DISCONNECT || code == ERR_SERVERDISCONNECT) {
 		VM_Forced_Unload_Start();
 		SV_Shutdown( "Server disconnected" );
+		if ( restartClient ) {
+			CL_Init();
+		}
 		CL_Disconnect( qtrue );
 		CL_FlushMemory( );
 		VM_Forced_Unload_Done();
@@ -310,6 +320,9 @@ void QDECL Com_Error( int code, const char *fmt, ... ) {
 		Com_Printf ("********************\nERROR: %s\n********************\n", com_errorMessage);
 		VM_Forced_Unload_Start();
 		SV_Shutdown (va("Server crashed: %s",  com_errorMessage));
+		if ( restartClient ) {
+			CL_Init();
+		}
 		CL_Disconnect( qtrue );
 		CL_FlushMemory( );
 		VM_Forced_Unload_Done();
@@ -319,6 +332,9 @@ void QDECL Com_Error( int code, const char *fmt, ... ) {
 	} else if ( code == ERR_NEED_CD ) {
 		VM_Forced_Unload_Start();
 		SV_Shutdown( "Server didn't have CD" );
+		if ( restartClient ) {
+			CL_Init();
+		}
 		if ( com_cl_running && com_cl_running->integer ) {
 			CL_Disconnect( qtrue );
 			CL_FlushMemory( );
@@ -2362,16 +2378,14 @@ void Com_GameRestart(int checksumFeed, qboolean disconnect)
 	// make sure no recursion can be triggered
 	if(!com_gameRestarting && com_fullyInitialized)
 	{
-		int clWasRunning;
-
 		com_gameRestarting = qtrue;
-		clWasRunning = com_cl_running->integer;
-		
+		com_gameClientRestarting = com_cl_running->integer;
+
 		// Kill server if we have one
 		if(com_sv_running->integer)
 			SV_Shutdown("Game directory changed");
 
-		if(clWasRunning)
+		if(com_gameClientRestarting)
 		{
 			if(disconnect)
 				CL_Disconnect(qfalse);
@@ -2393,13 +2407,14 @@ void Com_GameRestart(int checksumFeed, qboolean disconnect)
 			NET_Restart_f();
 		}
 
-		if(clWasRunning)
+		if(com_gameClientRestarting)
 		{
 			CL_Init();
 			CL_StartHunkUsers(qfalse);
 		}
 
 		com_gameRestarting = qfalse;
+		com_gameClientRestarting = qfalse;
 	}
 }