Only stop own soldiers from leaving attacked building

The idea is to potentially use those for defense.
However e.g. harbors might contain soldiers that belong to another
building and are about to leave.

Don't consider those as this complicates the logic too much.

Currently it crashed because adding "active" soldiers is assumed to be
either the defender or a soldier on a mission from this building.
Other soldiers will get lost in the accounting of their home building.

Fixes #1912

Author: Flamefire

libs/s25main/buildings/nobBaseMilitary.cpp

@@ -224,9 +224,8 @@ bool nobBaseMilitary::CallDefender(nofAttacker& attacker)
     // Stop attacking soldiers (including aggressive defenders) from leaving this building
     for(auto it = leave_house.begin(); it != leave_house.end();)
     {
-        if(!dynamic_cast<nofActiveSoldier*>(it->get()))
-            ++it;
-        else
+        const auto* sldPtr = dynamic_cast<nofActiveSoldier*>(it->get());
+        if(sldPtr && helpers::contains(troops_on_mission, sldPtr))
         {
             auto soldier = boost::static_pointer_cast<nofActiveSoldier>(std::move(*it));
             // At this point there shouldn't be a defender leaving as we are just requesting one
@@ -236,6 +235,12 @@ bool nobBaseMilitary::CallDefender(nofAttacker& attacker)
 
             soldier->InformTargetsAboutCancelling();
             AddActiveSoldier(std::move(soldier));
+        } else
+        {
+            // If a leaving active soldier is not on a mission he doesn't belong to this building.
+            // E.g. soldiers in harbors could be about to go home.
+            RTTR_Assert(!sldPtr || sldPtr->GetHomeBld() != this);
+            ++it;
         }
     }
     // Use existing defender (e.g. just going back in) if possible

libs/s25main/figures/nofSoldier.h

@@ -41,6 +41,7 @@ class nofSoldier : public noFigure
     unsigned char GetRank() const;
     unsigned char GetHitpoints() const;
     bool HasNoHome() const { return homeBld == nullptr; }
+    const nobBaseMilitary* GetHomeBld() const { return homeBld; }
 };
 
 /// Comparator to sort soldiers by rank and armor (and ID for ties), weak ones first