[Client] Clear FortifyAttribute effects when server sets modifier to 0

apps/openmw/mwmechanics/activespells.cpp

@@ -295,6 +295,30 @@ namespace MWMechanics
         mSpellsChanged = true;
     }
 
+    /*
+        Start of tes3mp addition
+
+        Allow the purging of an effect for a specific arg (attribute or skill)
+    */
+    void ActiveSpells::purgeEffectByArg(short effectId, int effectArg)
+    {
+        for (TContainer::iterator it = mSpells.begin(); it != mSpells.end(); ++it)
+        {
+            for (std::vector<ActiveEffect>::iterator effectIt = it->second.mEffects.begin();
+                effectIt != it->second.mEffects.end();)
+            {
+                if (effectIt->mEffectId == effectId && effectIt->mArg == effectArg)
+                    effectIt = it->second.mEffects.erase(effectIt);
+                else
+                    ++effectIt;
+            }
+        }
+        mSpellsChanged = true;
+    }
+    /*
+        End of tes3mp addition
+    */
+
     void ActiveSpells::clear()
     {
         mSpells.clear();

apps/openmw/mwmechanics/activespells.hpp

@@ -94,6 +94,16 @@ namespace MWMechanics
             /// Remove all effects with CASTER_LINKED flag that were cast by \a casterActorId
             void purge (int casterActorId);
 
+            /*
+                Start of tes3mp addition
+
+                Allow the purging of an effect for a specific arg (attribute or skill)
+            */
+            void purgeEffectByArg(short effectId, int effectArg);
+            /*
+                End of tes3mp addition
+            */
+
             /// Remove all spells
             void clear();
 

apps/openmw/mwmp/LocalPlayer.cpp

@@ -19,6 +19,7 @@
 
 #include "../mwinput/inputmanagerimp.hpp"
 
+#include "../mwmechanics/activespells.hpp"
 #include "../mwmechanics/aitravel.hpp"
 #include "../mwmechanics/creaturestats.hpp"
 #include "../mwmechanics/mechanicsmanagerimp.hpp"
@@ -790,6 +791,12 @@ void LocalPlayer::setAttributes()
 
     for (int i = 0; i < 8; ++i)
     {
+        // If the server wants to clear our attribute's non-zero modifier, we need to remove
+        // the spell effect causing it, to avoid an infinite loop where the effect keeps resetting
+        // the modifier
+        if (creatureStats.mAttributes[i].mMod == 0 && ptrCreatureStats->getAttribute(i).getModifier() > 0)
+            ptrCreatureStats->getActiveSpells().purgeEffectByArg(ESM::MagicEffect::FortifyAttribute, i);
+
         attributeValue.readState(creatureStats.mAttributes[i]);
         ptrCreatureStats->setAttribute(i, attributeValue);
     }