Fix prioritize teaching interaction, fixes #359

Source/Client/Patches/TeachingPatches.cs

@@ -0,0 +1,54 @@
+using HarmonyLib;
+using RimWorld;
+using Verse;
+using Verse.AI;
+
+namespace Multiplayer.Client.Patches;
+
+[HarmonyPatch(typeof(WorkGiver_Teach), nameof(WorkGiver_Teach.JobOnThing))]
+static class WorkGiverTeachUnsetTarget
+{
+    static bool Prefix(Thing t, ref Job __result)
+    {
+        // Only prevent the change from happening in interface, as it'll be called from
+        // FloatMenuMakerMap.AddJobGiverWorkOrders despite not assigning the job yet.
+        if (!Multiplayer.InInterface)
+            return true;
+        // If target is not pawn, no result
+        if (t is not Pawn pawn)
+            return false;
+
+        // Alternative approach would be to store the current target of the lesson taking pawn in the
+        // prefix before it's changed, and restore it in the finalizer.
+        __result = JobMaker.MakeJob(JobDefOf.Lessongiving, pawn.CurJob.GetTarget(TargetIndex.A), pawn);
+        return false;
+    }
+}
+
+[HarmonyPatch(typeof(Pawn_JobTracker), nameof(Pawn_JobTracker.TryTakeOrderedJob))]
+static class PawnJobTrackerSetTeacher
+{
+    static void Prefix(Pawn_JobTracker __instance, Job job)
+    {
+        // Check if it's lessongiving job, as we don't want to do anything else in any other case.
+        if (job.def != JobDefOf.Lessongiving)
+            return;
+
+        // We only need to set the teacher if we're executing a sync command, as the teacher
+        // wasn't set in interface due to us no allowing it to do so to prevent a desync.
+        if (!Multiplayer.ExecutingCmds)
+            return;
+
+        var student = job.GetTarget(TargetIndex.B).Pawn;
+        // Make sure the target B (JobDriver_Lessongiving.Student) is a non-null Pawn.
+        if (student == null)
+            return;
+
+        // Make sure the student is still doing the lessontaking job
+        if (student.CurJobDef == JobDefOf.Lessontaking)
+            student.CurJob.SetTarget(TargetIndex.B, __instance.pawn);
+
+        // We could check if the pawn can reach their target desk, but it'll
+        // be handled by JobDriver_Lessongiving.TryMakePreToilReservations
+    }
+}