Core/Players: Fixed spells being unintentionally removed by talent swaps when they are learned from more than one spell (affects balance druid Celesial Alignment and Incarnation)

(cherry picked from commit 2c6ddcce3d6374a82214bb0ddb9d7432351982c9)

# Conflicts:
#	src/server/game/Spells/SpellMgr.cpp

3 files changed, 29 insertions, 0 deletions

diff --git a/src/server/game/Entities/Player/Player.cpp b/src/server/game/Entities/Player/Player.cpp
index 432700be071..b6b7ea4b836 100644
--- a/src/server/game/Entities/Player/Player.cpp
+++ b/src/server/game/Entities/Player/Player.cpp
@@ -3107,6 +3107,18 @@ void Player::RemoveSpell(uint32 spell_id, bool disabled /*= false*/, bool learn_
 
     for (SpellLearnSpellMap::const_iterator itr2 = spell_bounds.first; itr2 != spell_bounds.second; ++itr2)
     {
+        bool hasOtherSpellTeachingThis = std::ranges::any_of(sSpellMgr->GetSpellLearnedBySpellMapBounds(itr2->second.Spell), [&](SpellLearnSpellNode const* learnNode)
+        {
+            if (learnNode->SourceSpell == spell_id)
+                return false;
+            if (!learnNode->Active)
+                return false;
+            return HasSpell(learnNode->SourceSpell);
+        }, &SpellLearnedBySpellMap::value_type::second);
+
+        if (hasOtherSpellTeachingThis)
+            continue;
+
         RemoveSpell(itr2->second.Spell, disabled);
         if (itr2->second.OverridesSpell)
             RemoveOverrideSpell(itr2->second.OverridesSpell, itr2->second.Spell);
diff --git a/src/server/game/Spells/SpellMgr.cpp b/src/server/game/Spells/SpellMgr.cpp
index b27f7db6dbd..ba212cb04b8 100644
--- a/src/server/game/Spells/SpellMgr.cpp
+++ b/src/server/game/Spells/SpellMgr.cpp
@@ -342,6 +342,11 @@ bool SpellMgr::IsSpellLearnToSpell(uint32 spell_id1, uint32 spell_id2) const
     return false;
 }
 
+Trinity::IteratorPair<SpellLearnedBySpellMap::const_iterator> SpellMgr::GetSpellLearnedBySpellMapBounds(uint32 learnedSpellId) const
+{
+    return Trinity::Containers::MapEqualRange(mSpellLearnedBySpells, learnedSpellId);
+}
+
 SpellTargetPosition const* SpellMgr::GetSpellTargetPosition(uint32 spell_id, SpellEffIndex effIndex) const
 {
     SpellTargetPositionMap::const_iterator itr = mSpellTargetPositions.find(std::make_pair(spell_id, effIndex));
@@ -1053,6 +1058,7 @@ void SpellMgr::LoadSpellLearnSpells()
 {
     uint32 oldMSTime = getMSTime();
 
+    mSpellLearnedBySpells.clear();
     mSpellLearnSpells.clear();                              // need for reload case
 
     //                                                  0      1        2
@@ -1071,6 +1077,7 @@ void SpellMgr::LoadSpellLearnSpells()
         uint32 spell_id = fields[0].GetUInt32();
 
         SpellLearnSpellNode node;
+        node.SourceSpell = spell_id;
         node.Spell       = fields[1].GetUInt32();
         node.OverridesSpell = 0;
         node.Active      = fields[2].GetBool();
@@ -1115,6 +1122,7 @@ void SpellMgr::LoadSpellLearnSpells()
             if (spellEffectInfo.IsEffect(SPELL_EFFECT_LEARN_SPELL))
             {
                 SpellLearnSpellNode dbc_node;
+                dbc_node.SourceSpell = entry.Id;
                 dbc_node.Spell = spellEffectInfo.TriggerSpell;
                 dbc_node.Active = true;                     // all dbc based learned spells is active (show in spell book or hide by client itself)
                 dbc_node.OverridesSpell = 0;
@@ -1188,6 +1196,7 @@ void SpellMgr::LoadSpellLearnSpells()
             continue;
 
         SpellLearnSpellNode dbcLearnNode;
+        dbcLearnNode.SourceSpell = spellLearnSpell->SpellID;
         dbcLearnNode.Spell = spellLearnSpell->LearnSpellID;
         dbcLearnNode.OverridesSpell = spellLearnSpell->OverridesSpellID;
         dbcLearnNode.Active = true;
@@ -1254,6 +1263,9 @@ void SpellMgr::LoadSpellLearnSpells()
         }
     }
 
+    for (auto const& [spellId, learnedSpellNode] : mSpellLearnSpells)
+        mSpellLearnedBySpells.emplace(learnedSpellNode.Spell, &learnedSpellNode);
+
     TC_LOG_INFO("server.loading", ">> Loaded {} spell learn spells, {} found in Spell.dbc and {} found in TalentTab.db2 in {} ms", count, dbc_count, mastery_count, GetMSTimeDiffToNow(oldMSTime));
 }
 
diff --git a/src/server/game/Spells/SpellMgr.h b/src/server/game/Spells/SpellMgr.h
index 91470991901..b681dcbf5cd 100644
--- a/src/server/game/Spells/SpellMgr.h
+++ b/src/server/game/Spells/SpellMgr.h
@@ -589,6 +589,7 @@ typedef std::unordered_map<uint32, SpellLearnSkillNode> SpellLearnSkillMap;
 
 struct SpellLearnSpellNode
 {
+    uint32 SourceSpell;
     uint32 Spell;
     uint32 OverridesSpell;
     bool Active;                    // show in spellbook or not
@@ -617,6 +618,8 @@ struct CreatureImmunities
 typedef std::multimap<uint32, SpellLearnSpellNode> SpellLearnSpellMap;
 typedef std::pair<SpellLearnSpellMap::const_iterator, SpellLearnSpellMap::const_iterator> SpellLearnSpellMapBounds;
 
+typedef std::multimap<uint32, SpellLearnSpellNode const*> SpellLearnedBySpellMap;
+
 typedef std::multimap<uint32, SkillLineAbilityEntry const*> SkillLineAbilityMap;
 typedef std::pair<SkillLineAbilityMap::const_iterator, SkillLineAbilityMap::const_iterator> SkillLineAbilityMapBounds;
 
@@ -723,6 +726,7 @@ class TC_GAME_API SpellMgr
         SpellLearnSpellMapBounds GetSpellLearnSpellMapBounds(uint32 spell_id) const;
         bool IsSpellLearnSpell(uint32 spell_id) const;
         bool IsSpellLearnToSpell(uint32 spell_id1, uint32 spell_id2) const;
+        Trinity::IteratorPair<SpellLearnedBySpellMap::const_iterator> GetSpellLearnedBySpellMapBounds(uint32 learnedSpellId) const;
 
         // Spell target coordinates
         SpellTargetPosition const* GetSpellTargetPosition(uint32 spell_id, SpellEffIndex effIndex) const;
@@ -827,6 +831,7 @@ class TC_GAME_API SpellMgr
         SpellRequiredMap           mSpellReq;
         SpellLearnSkillMap         mSpellLearnSkills;
         SpellLearnSpellMap         mSpellLearnSpells;
+        SpellLearnedBySpellMap     mSpellLearnedBySpells;
         SpellTargetPositionMap     mSpellTargetPositions;
         SpellSpellGroupMap         mSpellSpellGroup;
         SpellGroupSpellMap         mSpellGroupSpell;