Updated Chorus skill type effect

* Fixes 921
* Chorus skills now work as long as another performer is in the same party and on screen as the caster -- no longer has to be adjacent to caster.

src/map/skill.c

@@ -10740,12 +10740,6 @@ static int8 skill_castend_id_check(struct block_list *src, struct block_list *ta
 			break;
 	}
 
-	// Check partner
-	if (sd && (inf2&INF2_CHORUS_SKILL) && skill_check_pc_partner(sd, skill_id, &skill_lv, 1, 0) < 1 ) {
-		clif_skill_fail(sd, skill_id, USESKILL_FAIL_NEED_HELPER, 0);
-		return USESKILL_FAIL_NEED_HELPER;
-	}
-
 	if (inf&INF_ATTACK_SKILL ||
 		(inf&INF_SELF_SKILL && inf2&INF2_NO_TARGET_SELF) //Combo skills
 		) // Casted through combo.
@@ -14190,7 +14184,9 @@ int skill_check_condition_char_sub (struct block_list *bl, va_list ap)
 		return 0;
 
 	if( inf2&INF2_CHORUS_SKILL ) {
-		if( tsd->status.party_id == sd->status.party_id && (tsd->class_&MAPID_THIRDMASK) == MAPID_MINSTRELWANDERER )
+		if( tsd->status.party_id && sd->status.party_id &&
+				tsd->status.party_id == sd->status.party_id &&
+				(tsd->class_&MAPID_THIRDMASK) == MAPID_MINSTRELWANDERER )
 			p_sd[(*c)++] = tsd->bl.id;
 		return 1;
 	} else {
@@ -14294,10 +14290,7 @@ int skill_check_pc_partner(struct map_session_data *sd, uint16 skill_id, uint16
 	//Else: new search for partners.
 	c = 0;
 	memset (p_sd, 0, sizeof(p_sd));
-	if( is_chorus )
-		i = party_foreachsamemap(skill_check_condition_char_sub,sd,AREA_SIZE,&sd->bl, &c, &p_sd, skill_id, *skill_lv);
-	else
-		i = map_foreachinrange(skill_check_condition_char_sub, &sd->bl, range, BL_PC, &sd->bl, &c, &p_sd, skill_id);
+	i = map_foreachinrange(skill_check_condition_char_sub, &sd->bl, range, BL_PC, &sd->bl, &c, &p_sd, skill_id);
 
 	if ( skill_id != PR_BENEDICTIO && skill_id != AB_ADORAMUS && skill_id != WL_COMET ) //Apply the average lv to encore skills.
 		*skill_lv = (i+(*skill_lv))/(c+1); //I know c should be one, but this shows how it could be used for the average of n partners.
@@ -14527,7 +14520,7 @@ bool skill_check_condition_castbegin(struct map_session_data* sd, uint16 skill_i
 	// perform skill-group checks
 	inf2 = skill_get_inf2(skill_id);
 	if(inf2&INF2_CHORUS_SKILL) {
-		if ( skill_check_pc_partner(sd,skill_id,&skill_lv,skill_get_splash(skill_id,skill_lv),0) < 1 ){
+		if (skill_check_pc_partner(sd, skill_id, &skill_lv, AREA_SIZE, 0) < 1) {
 		    clif_skill_fail(sd,skill_id,USESKILL_FAIL_LEVEL,0);
 		    return false;
 		}
@@ -15063,7 +15056,7 @@ bool skill_check_condition_castbegin(struct map_session_data* sd, uint16 skill_i
 			break;
 		case WM_GREAT_ECHO: {
 				int count;
-				count = skill_check_pc_partner(sd, skill_id, &skill_lv, skill_get_splash(skill_id,skill_lv), 0);
+				count = skill_check_pc_partner(sd, skill_id, &skill_lv, AREA_SIZE, 0);
 				if( count < 1 ) {
 					clif_skill_fail(sd,skill_id,USESKILL_FAIL_NEED_HELPER,0);
 					return false;