From 36c4e56528873ce438c1b9dba7f9b9658c1be05e Mon Sep 17 00:00:00 2001
From: TomGoodIdea <108272452+TomGoodIdea@users.noreply.github.com>
Date: Sat, 14 Sep 2024 23:46:52 +0200
Subject: [PATCH] fix(mechanics): Improve handling of orders when the selected
 escort is destroyed (#10459)

- After a player ship has finished exploding, it is no longer considered "selected" and so will no longer block orders to the wider fleet.
- If orders are issued while all selected ships are exploding, a new message indicating that they cannot follow orders will be used, instead of the normal message indicating that orders have been issued.
---
 source/AI.cpp         | 25 +++++++++++++++++++++----
 source/Engine.cpp     |  3 +++
 source/PlayerInfo.cpp | 12 ++++++++++++
 source/PlayerInfo.h   |  1 +
 4 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/source/AI.cpp b/source/AI.cpp
index 34792689e473..9d6c45504943 100644
--- a/source/AI.cpp
+++ b/source/AI.cpp
@@ -4832,25 +4832,42 @@ void AI::IssueOrders(const Orders &newOrders, const string &description)
 
 	// Figure out what ships we are giving orders to.
 	vector<const Ship *> ships;
+	size_t destroyedCount = 0;
 	if(player.SelectedShips().empty())
 	{
 		for(const shared_ptr<Ship> &it : player.Ships())
 			if(it.get() != player.Flagship() && !it->IsParked())
-				ships.push_back(it.get());
-		who = ships.size() > 1 ? "Your fleet is " : "Your escort is ";
+			{
+				if(it->IsDestroyed())
+					++destroyedCount;
+				else
+					ships.push_back(it.get());
+			}
+		who = (ships.empty() ? destroyedCount : ships.size()) > 1
+			? "Your fleet is " : "Your escort is ";
 	}
 	else
 	{
 		for(const weak_ptr<Ship> &it : player.SelectedShips())
 		{
 			shared_ptr<Ship> ship = it.lock();
-			if(ship)
+			if(!ship)
+				continue;
+			if(ship->IsDestroyed())
+				++destroyedCount;
+			else
 				ships.push_back(ship.get());
 		}
-		who = ships.size() > 1 ? "The selected escorts are " : "The selected escort is ";
+		who = (ships.empty() ? destroyedCount : ships.size()) > 1
+			? "The selected escorts are " : "The selected escort is ";
 	}
 	if(ships.empty())
+	{
+		if(destroyedCount)
+			Messages::Add(who + "destroyed and unable to execute your orders.",
+				Messages::Importance::High);
 		return;
+	}
 
 	Point centerOfGravity;
 	bool isMoveOrder = (newOrders.HasMoveTo());
diff --git a/source/Engine.cpp b/source/Engine.cpp
index 4be71637fd01..ed061cb53720 100644
--- a/source/Engine.cpp
+++ b/source/Engine.cpp
@@ -1700,6 +1700,9 @@ void Engine::MoveShip(const shared_ptr<Ship> &ship)
 			for(const auto &bay : ship->Bays())
 				if(bay.ship)
 					eventQueue.emplace_back(nullptr, bay.ship, ShipEvent::DESTROY);
+			// If this is a player ship, make sure it's no longer selected.
+			if(ship->IsYours())
+				player.DeselectShip(ship.get());
 		}
 		return;
 	}
diff --git a/source/PlayerInfo.cpp b/source/PlayerInfo.cpp
index 51095570592a..4aabbe9bae82 100644
--- a/source/PlayerInfo.cpp
+++ b/source/PlayerInfo.cpp
@@ -2777,6 +2777,18 @@ void PlayerInfo::SelectShip(const Ship *ship, bool hasShift)
 
 
 
+void PlayerInfo::DeselectShip(const Ship *ship)
+{
+	for(auto it = selectedShips.begin(); it != selectedShips.end(); ++it)
+		if(it->lock().get() == ship)
+		{
+			selectedShips.erase(it);
+			return;
+		}
+}
+
+
+
 void PlayerInfo::SelectGroup(int group, bool hasShift)
 {
 	int bit = (1 << group);
diff --git a/source/PlayerInfo.h b/source/PlayerInfo.h
index c71198cd33ea..9392ad7daf38 100644
--- a/source/PlayerInfo.h
+++ b/source/PlayerInfo.h
@@ -307,6 +307,7 @@ class PlayerInfo {
 	bool SelectShips(const Rectangle &box, bool hasShift);
 	bool SelectShips(const std::vector<const Ship *> &stack, bool hasShift);
 	void SelectShip(const Ship *ship, bool hasShift);
+	void DeselectShip(const Ship *ship);
 	void SelectGroup(int group, bool hasShift);
 	void SetGroup(int group, const std::set<Ship *> *newShips = nullptr);
 	std::set<Ship *> GetGroup(int group);