Attract: fix attract demos end handling

Fixes two bugs:

- Attract mode carrying over to gameplay if an attract
  demo is allowed to finish without interrupting it
- Credits ending after the first replay ends

src/d_main.cpp

@@ -1131,6 +1131,8 @@ static boolean g_deferredtitle = false;
 //
 void D_StartTitle(void)
 {
+	demo.attract = DEMO_ATTRACT_OFF;
+
 	Music_StopAll();
 
 	D_ClearState();

src/d_netcmd.c

@@ -71,6 +71,7 @@
 #include "k_roulette.h"
 #include "k_bans.h"
 #include "k_director.h"
+#include "k_credits.h"
 
 #ifdef SRB2_CONFIG_ENABLE_WEBM_MOVIES
 #include "m_avrecorder.h"
@@ -6374,14 +6375,20 @@ void Command_ExitGame_f(void)
 
 	if (!modeattacking)
 	{
-		if (restoreMenu == NULL)
+		// YES, this is where demo.attract gets cleared!
+		if (demo.attract == DEMO_ATTRACT_CREDITS)
 		{
-			D_StartTitle();
+			F_ContinueCredits(); // <-- clears demo.attract
+		}
+		else if (restoreMenu == NULL) // this is true for attract demos too!
+		{
+			D_StartTitle(); // <-- clears demo.attract
 		}
 		else
 		{
 			D_ClearState();
 			M_StartControlPanel();
+			demo.attract = DEMO_ATTRACT_OFF; // shouldn't ever happen, but let's keep the code symmetrical
 		}
 	}
 }

src/g_game.c

@@ -1348,7 +1348,6 @@ boolean G_Responder(event_t *ev)
 			{
 				// stop the title demo
 				G_CheckDemoStatus();
-				demo.attract = DEMO_ATTRACT_OFF;
 				return true;
 			}
 		}

src/k_credits.cpp

@@ -430,6 +430,7 @@ void F_ContinueCredits(void)
 {
 	G_SetGamestate(GS_CREDITS);
 	F_CreditsReset();
+	demo.attract = DEMO_ATTRACT_OFF;
 
 	// Returning from playing a demo.
 	// Go to the next slide.

src/menus/transient/pause-replay.c

@@ -94,8 +94,12 @@ void M_EndModeAttackRun(void)
 		// - Now we need to clear the rest of the gamestate ourself!
 	}
 
-	// Playback: modeattacking is always false, so calling this returns to the menu.
-	// Recording: modeattacking is still true and this function call preserves that.
+	// Playback:
+	// - modeattacking is always false, so calling this returns to the menu.
+	// - Because modeattacking is false, also clears demo.attract.
+	//
+	// Recording:
+	// - modeattacking is still true and this function call preserves that.
 	Command_ExitGame_f();
 
 	if (!modeattacking)
@@ -123,19 +127,8 @@ void M_EndModeAttackRun(void)
 	modeattacking = ATTACKING_NONE;
 
 	// Return to the menu.
-	if (demo.attract == DEMO_ATTRACT_TITLE)
-	{
-		D_SetDeferredStartTitle(true);
-	}
-	else if (demo.attract == DEMO_ATTRACT_CREDITS)
-	{
-		F_ContinueCredits();
-	}
-	else
-	{
-		D_ClearState();
-		M_StartControlPanel();
-	}
+	D_ClearState();
+	M_StartControlPanel();
 }
 
 // Replay Playback Menu

src/p_setup.cpp

@@ -8342,8 +8342,10 @@ boolean P_LoadLevel(boolean fromnetsave, boolean reloadinggamestate)
 
 	P_InitLevelSettings();
 
-	if (demo.attract != DEMO_ATTRACT_TITLE)
+	if (demo.attract != DEMO_ATTRACT_TITLE && gamestate != GS_TITLESCREEN)
 	{
+		// Stop titlescreen music from overriding level music.
+		// Except on the title screen, where an attract demo or title map may be used.
 		Music_Stop("title");
 	}