Let multiple modules limit autostaging and add/remove independently

This way they don't scribble over what each other wants, and the
staging controller is responsible for tracking and satisfying
multiple requests.

Signed-off-by: Lamont Granquist <lamont@scriptkiddie.org>

MechJeb2/MechJebModuleGuidanceController.cs

@@ -300,7 +300,7 @@ private void HandleThrottle()
             // RCS trim, autostaging will stage off the spent engine if there's no relights.  This is unwanted
             // since the insertion stage may still have RCS which is necessary to complete the mission.
             if (coastStage >= 0 && Vessel.currentStage == coastStage && Solution.WillCoast(VesselState.time))
-                Core.Staging.autostageLimitInternal = coastStage;
+                Core.Staging.AutoStageLimitRequest(coastStage, this);
 
             if (Solution.Coast(VesselState.time))
             {
@@ -321,7 +321,7 @@ private void HandleThrottle()
                 return;
             }
 
-            Core.Staging.autostageLimitInternal = Solution.TerminalStage();
+            Core.Staging.AutoStageLimitRequest(Solution.TerminalStage(), this);
 
             ThrottleOn();
 

MechJeb2/MechJebModuleSpinupController.cs

@@ -37,8 +37,7 @@ protected override void OnModuleDisabled()
             _state = SpinupState.FINISHED;
             Core.Attitude.SetOmegaTarget(roll: double.NaN);
             Core.Attitude.SetActuationControl();
-            // FIXME: this might overwrite someone else, but the only other consumer so far is the GuidanceController
-            Core.Staging.autostageLimitInternal = 0;
+            Core.Staging.AutoStageLimitRemove( this);
             Core.Attitude.Users.Remove(this);
             base.OnModuleDisabled();
         }
@@ -65,7 +64,7 @@ public override void Drive(FlightCtrlState s)
             if (_state == SpinupState.INITIALIZED)
                 return;
 
-            Core.Staging.autostageLimitInternal = Vessel.currentStage;
+            Core.Staging.AutoStageLimitRequest(Vessel.currentStage, this);
 
             if (VesselState.time < _startTime)
                 return;

MechJeb2/MechJebModuleStagingController.cs

@@ -55,8 +55,27 @@ public MechJebModuleStagingController(MechJebCore core)
 
         public bool waitingForFirstStaging;
 
-        // this is for other modules to temporarily disable autostaging (e.g. PVG coast phases)
-        public int autostageLimitInternal;
+        private readonly Dictionary<object, int> _autoStageModuleLimit = new Dictionary<object, int>();
+
+        public void AutoStageLimitRequest(int stage, object user)
+        {
+            _autoStageModuleLimit.TryAdd(user, stage);
+        }
+
+        public void AutoStageLimitRemove(object user)
+        {
+            if (_autoStageModuleLimit.ContainsKey(user))
+                _autoStageModuleLimit.Remove(user);
+        }
+
+        private int ActiveAutoStageModuleLimit()
+        {
+            int limit = 0;
+            foreach(int key in _autoStageModuleLimit.Values)
+                if (key > limit)
+                    limit = key;
+            return limit;
+        }
 
         private readonly List<ModuleEngines>     activeModuleEngines             = new List<ModuleEngines>(16);
         private readonly List<ModuleEngines>     allModuleEngines                = new List<ModuleEngines>(16);
@@ -161,7 +180,7 @@ public void AutostageOnce(object user)
 
         protected override void OnModuleEnabled()
         {
-            autostageLimitInternal = 0;
+            _autoStageModuleLimit.Clear();
         }
 
         protected override void OnModuleDisabled()
@@ -269,7 +288,7 @@ public override void OnUpdate()
 
             // this is for PVG preventing staging doing coasts, possibly it should be more specific of an API
             // (e.g. bool PVGIsCoasting) since it is getting tightly coupled.
-            if (Vessel.currentStage <= autostageLimitInternal)
+            if (Vessel.currentStage <= ActiveAutoStageModuleLimit())
             {
                 // force staging once if fairing conditions are met in the next stage
                 if (HasFairing(Vessel.currentStage - 1) && !WaitingForFairing())