Don't clear known spells when reading from the savegame

This is needed because the .ess format doesn't include the racial spells in the player's spell list.

apps/essimporter/importplayer.cpp

@@ -23,6 +23,10 @@ namespace ESSImport
             mKnownDialogueTopics.push_back(esm.getHString());
         }
 
+        if (esm.isNextSub("MNAM"))
+            esm.skipHSub(); // If this field is here it seems to specify the interior cell the player is in,
+                            // but it's not always here, so it's kinda useless
+
         esm.getHNT(mPNAM, "PNAM");
 
         if (esm.isNextSub("SNAM"))

apps/openmw/mwmechanics/spells.cpp

@@ -312,21 +312,17 @@ namespace MWMechanics
 
     void Spells::readState(const ESM::SpellState &state)
     {
-        mSpells = state.mSpells;
-        mSelectedSpell = state.mSelectedSpell;
-
-        // Discard spells that are no longer available due to changed content files
-        for (TContainer::iterator iter = mSpells.begin(); iter!=mSpells.end();)
+        for (TContainer::const_iterator it = state.mSpells.begin(); it != state.mSpells.end(); ++it)
         {
-            const ESM::Spell* spell = MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().search(iter->first);
-            if (!spell)
+            // Discard spells that are no longer available due to changed content files
+            const ESM::Spell* spell = MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().search(it->first);
+            if (spell)
             {
-                if (iter->first == mSelectedSpell)
-                    mSelectedSpell = "";
-                mSpells.erase(iter++);
+                mSpells[it->first] = it->second;
+
+                if (it->first == state.mSelectedSpell)
+                    mSelectedSpell = it->first;
             }
-            else
-                ++iter;
         }
 
         // No need to discard spells here (doesn't really matter if non existent ids are kept)

components/esm/spellstate.hpp

@@ -12,6 +12,7 @@ namespace ESM
     class ESMReader;
     class ESMWriter;
 
+    // NOTE: spell ids must be lower case
     struct SpellState
     {
         struct CorprusStats