set flag to allow forced unload of a running VM

required to prevent a client from exiting if the server disconnects (bug 3585)

code/qcommon/common.c

@@ -277,7 +277,9 @@ void QDECL Com_Error( int code, const char *fmt, ... ) {
 
 	if (code == ERR_DISCONNECT || code == ERR_SERVERDISCONNECT) {
 		CL_Disconnect( qtrue );
+		VM_Forced_Unload_Start();
 		CL_FlushMemory( );
+		VM_Forced_Unload_Done();
 		// make sure we can get at our local stuff
 		FS_PureServerSetLoadedPaks("", "");
 		com_errorEntered = qfalse;

code/qcommon/qcommon.h

@@ -325,6 +325,8 @@ vm_t	*VM_Create( const char *module, intptr_t (*systemCalls)(intptr_t *),
 
 void	VM_Free( vm_t *vm );
 void	VM_Clear(void);
+void	VM_Forced_Unload_Start(void);
+void	VM_Forced_Unload_Done(void);
 vm_t	*VM_Restart( vm_t *vm );
 
 intptr_t		QDECL VM_Call( vm_t *vm, int callNum, ... );

code/qcommon/vm.c

@@ -40,6 +40,9 @@ vm_t	*currentVM = NULL;
 vm_t	*lastVM    = NULL;
 int		vm_debugLevel;
 
+// used by Com_Error to get rid of running vm's before longjmp
+static int forced_unload;
+
 #define	MAX_VM		3
 vm_t	vmTable[MAX_VM];
 
@@ -613,8 +616,12 @@ void VM_Free( vm_t *vm ) {
 	}
 
 	if(vm->callLevel) {
+		if(!forced_unload) {
 			Com_Error( ERR_FATAL, "VM_Free(%s) on running vm", vm->name );
 			return;
+		} else {
+			Com_Printf( "forcefully unloading %s vm\n", vm->name );
+		}
 	}
 
 	if(vm->destroy)
@@ -648,6 +655,14 @@ void VM_Clear(void) {
 	}
 }
 
+void VM_Forced_Unload_Start(void) {
+	forced_unload = 1;
+}
+
+void VM_Forced_Unload_Done(void) {
+	forced_unload = 0;
+}
+
 void *VM_ArgPtr( intptr_t intValue ) {
 	if ( !intValue ) {
 		return NULL;