- be more thorough with 'in menu' checks for certain protected functions.

They would also pass the test if a menu just was open but not the actual invoker.
Also error out if this happens so that modders can see that they are doing unsupported things. Silent failure is not a good idea here.

src/c_bind.cpp

@@ -45,6 +45,7 @@
 #include "dobject.h"
 #include "vm.h"
 #include "i_time.h"
+#include "menu/menu.h"
 
 const char *KeyNames[NUM_KEYS] =
 {
@@ -267,6 +268,14 @@ DEFINE_ACTION_FUNCTION(FKeyBindings, SetBind)
 	PARAM_SELF_STRUCT_PROLOGUE(FKeyBindings);
 	PARAM_INT(k);
 	PARAM_STRING(cmd);
+
+	// Only menus are allowed to change bindings.
+	if (DMenu::InMenu == 0)
+	{
+		I_FatalError("Attempt to change key bindings outside of menu code to '%s'", cmd.GetChars());
+	}
+
+
 	self->SetBind(k, cmd);
 	return 0;
 }
@@ -506,6 +515,13 @@ DEFINE_ACTION_FUNCTION(FKeyBindings, UnbindACommand)
 {
 	PARAM_SELF_STRUCT_PROLOGUE(FKeyBindings);
 	PARAM_STRING(cmd);
+
+	// Only menus are allowed to change bindings.
+	if (DMenu::InMenu == 0)
+	{
+		I_FatalError("Attempt to unbind key bindings for '%s' outside of menu code", cmd.GetChars());
+	}
+
 	self->UnbindACommand(cmd);
 	return 0;
 }

src/c_cvars.cpp

@@ -220,7 +220,14 @@ DEFINE_ACTION_FUNCTION(_CVar, SetInt)
 {
 	// Only menus are allowed to change CVARs.
 	PARAM_SELF_STRUCT_PROLOGUE(FBaseCVar);
-	if (!(self->GetFlags() & CVAR_MOD) && CurrentMenu == nullptr) return 0;
+	if (!(self->GetFlags() & CVAR_MOD))
+	{
+		// Only menus are allowed to change non-mod CVARs.
+		if (DMenu::InMenu == 0)
+		{
+			I_FatalError("Attempt to change CVAR '%s' outside of menu code", self->GetName());
+		}
+	}
 	PARAM_INT(val);
 	UCVarValue v;
 	v.Int = val;
@@ -230,9 +237,15 @@ DEFINE_ACTION_FUNCTION(_CVar, SetInt)
 
 DEFINE_ACTION_FUNCTION(_CVar, SetFloat)
 {
-	// Only menus are allowed to change CVARs.
 	PARAM_SELF_STRUCT_PROLOGUE(FBaseCVar);
-	if (!(self->GetFlags() & CVAR_MOD) && CurrentMenu == nullptr) return 0;
+	if (!(self->GetFlags() & CVAR_MOD))
+	{
+		// Only menus are allowed to change non-mod CVARs.
+		if (DMenu::InMenu == 0)
+		{
+			I_FatalError("Attempt to change CVAR '%s' outside of menu code", self->GetName());
+		}
+	}
 	PARAM_FLOAT(val);
 	UCVarValue v;
 	v.Float = (float)val;
@@ -244,7 +257,14 @@ DEFINE_ACTION_FUNCTION(_CVar, SetString)
 {
 	// Only menus are allowed to change CVARs.
 	PARAM_SELF_STRUCT_PROLOGUE(FBaseCVar);
-	if (!(self->GetFlags() & CVAR_MOD) && CurrentMenu == nullptr) return 0;
+	if (!(self->GetFlags() & CVAR_MOD))
+	{
+		// Only menus are allowed to change non-mod CVARs.
+		if (DMenu::InMenu == 0)
+		{
+			I_FatalError("Attempt to change CVAR '%s' outside of menu code", self->GetName());
+		}
+	}
 	PARAM_STRING(val);
 	UCVarValue v;
 	v.String = val.GetChars();

src/menu/menu.cpp

@@ -53,6 +53,7 @@
 #include "events.h"
 #include "scripting/types.h"
 
+int DMenu::InMenu;
 //
 // Todo: Move these elsewhere
 //
@@ -190,7 +191,9 @@ bool DMenu::CallResponder(event_t *ev)
 			VMValue params[] = { (DObject*)this, &e };
 			int retval;
 			VMReturn ret(&retval);
+			InMenu++;
 			VMCall(func, params, 2, &ret, 1);
+			InMenu--;
 			return !!retval;
 		}
 	}
@@ -202,7 +205,9 @@ bool DMenu::CallResponder(event_t *ev)
 			VMValue params[] = { (DObject*)this, &e };
 			int retval;
 			VMReturn ret(&retval);
+			InMenu++;
 			VMCall(func, params, 2, &ret, 1);
+			InMenu--;
 			return !!retval;
 		}
 	}
@@ -222,7 +227,9 @@ bool DMenu::CallMenuEvent(int mkey, bool fromcontroller)
 		VMValue params[] = { (DObject*)this, mkey, fromcontroller };
 		int retval;
 		VMReturn ret(&retval);
+		InMenu++;
 		VMCall(func, params, 3, &ret, 1);
+		InMenu--;
 		return !!retval;
 	}
 	else return false;

src/menu/menu.h

@@ -265,6 +265,7 @@ public:
 	bool mMouseCapture;
 	bool mBackbuttonSelected;
 	bool DontDim;
+	static int InMenu;
 
 	DMenu(DMenu *parent = NULL);
 	bool TranslateKeyboardEvents();