fix(Core/Scripting): ask OnPlayerCanLearnSpell before a trainer casts an entry (#27707)

Co-authored-by: Claude Opus 5 <[email protected]>

src/server/game/Entities/Creature/Trainer.cpp

@@ -111,11 +111,13 @@ namespace Trainer
         npc->SendPlaySpellVisual(179); // 53 SpellCastDirected
         npc->SendPlaySpellImpact(player->GetGUID(), 362); // 113 EmoteSalute
 
-        // learn explicitly or cast explicitly
-        if (trainerSpell->IsCastable())
-            player->CastSpell(player, trainerSpell->SpellId, true);
-        else
+        // learn explicitly or cast explicitly. A cast puts each wrapped spell through learnSpell and
+        // its hook, but also runs whatever else the entry does (a class mount steps the Riding skill),
+        // so the entry itself is put to the hook first and a refusal skips the cast as a whole
+        if (!trainerSpell->IsCastable())
             player->learnSpell(trainerSpell->SpellId, false);
+        else if (sScriptMgr->OnPlayerCanLearnSpell(player, trainerSpell->SpellId))
+            player->CastSpell(player, trainerSpell->SpellId, true);
 
         SendTeachSucceeded(npc, player, spellId);
 

src/server/game/Scripting/ScriptDefines/PlayerScript.h

@@ -891,18 +891,21 @@ public:
      * did. A trainer has taken the money and still reports success, and Player::LearnTalent spends
      * the point and records the talent anyway -- use OnPlayerCanLearnTalent to stop a talent.
      *
-     * Only Player::learnSpell reaches it; spells written through addSpell do not. Those bypasses
-     * include character loading (_LoadSpells, and the initial class and skill-rewarded spells,
-     * which run on every login) and talent spells from _addTalentAurasAndSpells, reapplied on
-     * every dual-spec switch -- so a refusal in world is undone the next time one of them runs.
+     * Player::learnSpell reaches it, and so does a trainer about to cast a wrapper entry (below);
+     * spells written through addSpell do not. Those bypasses include character loading
+     * (_LoadSpells, and the initial class and skill-rewarded spells, which run on every login) and
+     * talent spells from _addTalentAurasAndSpells, reapplied on every dual-spec switch -- so a
+     * refusal in world is undone the next time one of them runs.
      *
      * What it sees can be indirect: a trainer entry that wraps other spells (a paladin's Summon
-     * Warhorse) is cast, so the hook sees the wrapped spells instead. A talent rank arrives only
-     * when it lands in the spell book, which most do not -- but a learn-spell talent still
-     * delivers its additional talent spells.
+     * Warhorse) is cast, so the hook sees the entry first and then each wrapped spell as the cast
+     * teaches it. Refusing the entry skips the cast as a whole, and with it whatever else the entry
+     * does: a class mount also steps the Riding skill, which refusing the wrapped spells alone does
+     * not stop. A talent rank arrives only when it lands in the spell book, which most do not -- but
+     * a learn-spell talent still delivers its additional talent spells.
      *
      * @param player Contains information about the Player
-     * @param spellId The id of the spell about to be learned
+     * @param spellId The id of the spell about to be learned, or of the trainer entry about to be cast
      *
      * @return true if the player is allowed to learn the spell
      */