gameplay: fix enforcer pierce bugs

fix a seeming typo on resistance piercing for the battallion's backup.
there is no evidence I could find that mod_ignore_resists_absorbs ever existed
as a valid attribute, so change it to the correct mod_pierce_resists_absorbs
that is used by the enforcer

also add an exclusion for the mult_dmgtaken_from_bullets. the Pain Train
uses this to add bullet vulnerability, so the enforcer actually does less damage
in this case since it "pierces" the vulnerability. technically, the pierce resistance
attribute should also do this check for all other damage types for compatibility
with attribute mods, but that's a more extensive change than just addressing it
for the vanilla case.

Author: mastercoms

src/game/shared/tf/tf_gamerules.cpp

@@ -6183,7 +6183,7 @@ bool CTFGameRules::ApplyOnDamageModifyRules( CTakeDamageInfo &info, CBaseEntity
 	}
 
 	int iPierceResists = 0;
-	CALL_ATTRIB_HOOK_INT_ON_OTHER( pWeapon, iPierceResists, mod_ignore_resists_absorbs );
+	CALL_ATTRIB_HOOK_INT_ON_OTHER( pWeapon, iPierceResists, mod_pierce_resists_absorbs );
 
 	// Use defense buffs if it's not a backstab or direct crush damage (telefrage, etc.)
 	if ( pVictim && info.GetDamageCustom() != TF_DMG_CUSTOM_BACKSTAB && ( info.GetDamageType() & DMG_CRUSH ) == 0 )
@@ -6833,10 +6833,11 @@ float CTFGameRules::ApplyOnDamageAliveModifyRules( const CTakeDamageInfo &info,
 		// Check if we're immune
 		outParams.bPlayDamageReductionSound = CheckForDamageTypeImmunity( info.GetDamageType(), pVictim, flDamageBase, flDamageBonus );
 
+		// Reduce only the crit portion of the damage with crit resist
+			bool bCrit = ( info.GetDamageType() & DMG_CRITICAL ) > 0;
+
 		if ( !iPierceResists )
 		{
-			// Reduce only the crit portion of the damage with crit resist
-			bool bCrit = ( info.GetDamageType() & DMG_CRITICAL ) > 0;
 			if ( bCrit )
 			{
 				// Break the damage down and reassemble
@@ -6876,15 +6877,23 @@ float CTFGameRules::ApplyOnDamageAliveModifyRules( const CTakeDamageInfo &info,
 					outParams.bPlayDamageReductionSound = CheckMedicResist( TF_COND_MEDIGUN_SMALL_BLAST_RESIST, TF_COND_MEDIGUN_UBER_BLAST_RESIST, pVictim, flRawDamage, flDamageBase, bCrit, flDamageBonus );
 				}
 			}
+		}
 
-			if ( info.GetDamageType() & (DMG_BULLET|DMG_BUCKSHOT) )
+		if ( info.GetDamageType() & (DMG_BULLET|DMG_BUCKSHOT) )
+		{
+			float flResist = 1.0f;
+			CALL_ATTRIB_HOOK_FLOAT_ON_OTHER( pVictim, flResist, mult_dmgtaken_from_bullets );
+			// If the resist is actually a vulnerability, apply it even if we're piercing resists
+			if ( flResist > 1.0f || !iPierceResists )
 			{
-				CALL_ATTRIB_HOOK_FLOAT_ON_OTHER( pVictim, flDamageBase, mult_dmgtaken_from_bullets );
-
+				flDamageBase *= flResist;
 				// Check for medic resist
 				outParams.bPlayDamageReductionSound = CheckMedicResist( TF_COND_MEDIGUN_SMALL_BULLET_RESIST, TF_COND_MEDIGUN_UBER_BULLET_RESIST, pVictim, flRawDamage, flDamageBase, bCrit, flDamageBonus );
 			}
+		}
 
+		if ( !iPierceResists )
+		{
 			if ( info.GetDamageType() & DMG_MELEE )
 			{
 				CALL_ATTRIB_HOOK_FLOAT_ON_OTHER( pVictim, flDamageBase, mult_dmgtaken_from_melee );