opening additional merc slots

common/emu_oplist.h

@@ -376,6 +376,7 @@ N(OP_MercenaryDismiss),
 N(OP_MercenaryHire),
 N(OP_MercenarySuspendRequest),
 N(OP_MercenarySuspendResponse),
+N(OP_MercenarySwitch),
 N(OP_MercenaryTimer),
 N(OP_MercenaryTimerRequest),
 N(OP_MercenaryUnknown1),

common/eq_packet_structs.h

@@ -6236,6 +6236,12 @@ struct SuspendMercenary_Struct {
 /*0001*/
 };
 
+// [OPCode: 0x1b37 (RoF2)] [Client->Server] [Size: 4]
+struct SwitchMercenary_Struct {
+/*0000*/	uint32	MercIndex;	// 0-based UI index into owned merc list
+/*0004*/
+};
+
 // [OPCode: 0x2528] On Live as of April 2 2012 [Server->Client] [Size: 4]
 // Response to suspend merc with timestamp
 struct SuspendMercenaryResponse_Struct {

common/patches/rof2.cpp

@@ -2323,7 +2323,7 @@ namespace RoF2
 					VARSTRUCT_ENCODE_TYPE(uint32, Buffer, emu->MercData[r].Stances[k].Stance);
 				}
 			}
-			VARSTRUCT_ENCODE_TYPE(uint32, Buffer, emu->MercData[0].MercUnk05);	// MercUnk05
+			VARSTRUCT_ENCODE_TYPE(uint32, Buffer, emu->MercData[0].MercUnk05);	// MercUnk05 - trailing field (unlocked slot count)
 		}
 		else
 		{

common/ruletypes.h

@@ -255,7 +255,7 @@ RULE_BOOL(Mercs, AllowMercSuspendInCombat, true, "Allow merc suspend in combat")
 RULE_BOOL(Mercs, MercsIgnoreLevelBasedHasteCaps, false, "Ignores hard coded level based haste caps.")
 RULE_INT(Mercs, MercsHasteCap, 100, "Haste cap for non-v3(over haste) haste")
 RULE_INT(Mercs, MercsHastev3Cap, 25, "Haste cap for v3(over haste) haste")
-RULE_INT(Mercs, MaxMercSlots, 6, "Maximum number of mercenary slots per character (max 11)")
+RULE_INT(Mercs, MaxMercSlots, 6, "Maximum number of mercenary slots per character (max 6)")
 RULE_CATEGORY_END()
 
 RULE_CATEGORY(Guild)

utils/patches/patch_RoF2.conf

@@ -418,6 +418,7 @@ OP_MercenaryUnknown1=0x5d26
 OP_MercenaryCommand=0x27f2
 OP_MercenarySuspendRequest=0x4407
 OP_MercenarySuspendResponse=0x6f03
+OP_MercenarySwitch=0x1b37
 OP_MercenaryUnsuspendResponse=0x27a0
 
 # Looting

zone/client.cpp

@@ -7958,21 +7958,19 @@ void Client::SendMercPersonalInfo()
 		mdus->MercStatus = 0;
 		mdus->MercCount  = mercCount;
 
+		// Lambda to populate a single merc entry in the packet
 		int max_slots = std::min(RuleI(Mercs, MaxMercSlots), MAXMERCS);
 		uint32 merc_index = 0;
-		for (int slot = 0; slot < max_slots && merc_index < MAX_MERC; slot++) {
-			auto& info = GetMercInfo(slot);
-			if (info.mercid == 0) {
-				continue;
-			}
 
-			Message(Chat::Yellow, "SendMercPersonalInfo: slot %i, mercid %u, templateid %u, name '%s', suspended %i",
+		auto fillMercEntry = [&](int slot) {
-				slot, info.mercid, info.MercTemplateID, info.merc_name, info.IsSuspended);
+			auto& info = GetMercInfo(slot);
+			if (info.mercid == 0 || merc_index >= MAX_MERC) {
+				return;
+			}
 
 			auto tmpl_it = zone->merc_templates.find(info.MercTemplateID);
 			if (tmpl_it == zone->merc_templates.end()) {
-				Message(Chat::Red, "SendMercPersonalInfo: slot %i template %u NOT FOUND, skipping", slot, info.MercTemplateID);
+				return;
-				continue;
 			}
 
 			MercTemplate *mercData = &tmpl_it->second;
@@ -7984,7 +7982,7 @@ void Client::SendMercPersonalInfo()
 
 			if (stancecount > MAX_MERC_STANCES) {
 				Log(Logs::General, Logs::Mercenaries, "SendMercPersonalInfo: stance count %u exceeds max for slot %i, skipping", stancecount, slot);
-				continue;
+				return;
 			}
 
 			mdus->MercData[merc_index].MercID            = mercData->MercTemplateID;
@@ -7999,7 +7997,7 @@ void Client::SendMercPersonalInfo()
 			mdus->MercData[merc_index].MercUnk01         = 0;
 			mdus->MercData[merc_index].TimeLeft          = info.MercTimerRemaining;
 			mdus->MercData[merc_index].MerchantSlot      = merc_index + 1;
-			mdus->MercData[merc_index].MercUnk02         = 1;
+			mdus->MercData[merc_index].MercUnk02         = (slot == GetMercSlot()) ? 1 : 0;
 			mdus->MercData[merc_index].StanceCount       = stancecount;
 			mdus->MercData[merc_index].MercUnk03         = 0;
 			mdus->MercData[merc_index].MercUnk04         = 1;
@@ -8017,6 +8015,20 @@ void Client::SendMercPersonalInfo()
 
 			mdus->MercData[merc_index].MercUnk05 = std::min(RuleI(Mercs, MaxMercSlots), MAXMERCS);
 			merc_index++;
+		};
+
+		// Emit the active merc slot first — the client marks the first entry
+		// in the list with the X (active marker), so order matters.
+		if (GetMercSlot() < max_slots && GetMercInfo().mercid != 0) {
+			fillMercEntry(GetMercSlot());
+		}
+
+		// Then emit remaining owned mercs in slot order
+		for (int slot = 0; slot < max_slots; slot++) {
+			if (slot == GetMercSlot()) {
+				continue; // already emitted
+			}
+			fillMercEntry(slot);
 		}
 
 		// Update count in case we skipped any invalid entries

zone/client_packet.cpp

@@ -305,6 +305,7 @@ void MapOpcodes()
 	ConnectedOpcodes[OP_MercenaryDismiss] = &Client::Handle_OP_MercenaryDismiss;
 	ConnectedOpcodes[OP_MercenaryHire] = &Client::Handle_OP_MercenaryHire;
 	ConnectedOpcodes[OP_MercenarySuspendRequest] = &Client::Handle_OP_MercenarySuspendRequest;
+	ConnectedOpcodes[OP_MercenarySwitch] = &Client::Handle_OP_MercenarySwitch;
 	ConnectedOpcodes[OP_MercenaryTimerRequest] = &Client::Handle_OP_MercenaryTimerRequest;
 	ConnectedOpcodes[OP_MoveCoin] = &Client::Handle_OP_MoveCoin;
 	ConnectedOpcodes[OP_MoveItem] = &Client::Handle_OP_MoveItem;
@@ -10430,7 +10431,7 @@ void Client::Handle_OP_MercenaryCommand(const EQApplicationPacket *app)
 	}
 
 	MercenaryCommand_Struct* mc = (MercenaryCommand_Struct*)app->pBuffer;
-	uint32 merc_command = mc->MercCommand;	// Seen 0 (zone in with no merc or suspended), 1 (dismiss merc), 5 (normal state), 20 (unknown), 36 (zone in with merc)
+	uint32 merc_command = mc->MercCommand;	// Seen 0 (zone in with no merc or suspended), 1 (stance/state update), 5 (normal state), 20 (unknown), 36 (zone in with merc)
 	int32 option = mc->Option;	// Seen -1 (zone in with no merc), 0 (setting to passive stance), 1 (normal or setting to balanced stance)
 
 	Log(Logs::General, Logs::Mercenaries, "Command %i, Option %i received from %s.", merc_command, option, GetName());
@@ -10438,9 +10439,6 @@ void Client::Handle_OP_MercenaryCommand(const EQApplicationPacket *app)
 	if (!RuleB(Mercs, AllowMercs))
 		return;
 
-	// Handle the Command here...
-	// Will need a list of what every type of command is supposed to do
-	// Unsure if there is a server response to this packet
 	if (option >= 0)
 	{
 		Merc* merc = GetMerc();
@@ -10496,14 +10494,14 @@ void Client::Handle_OP_MercenaryDataRequest(const EQApplicationPacket *app)
 	if (merchant_id == 0) {
 
 		//send info about your current merc(s)
-		if (GetMercInfo().mercid)
+		if (GetNumberOfMercenaries() > 0)
 		{
 			Log(Logs::General, Logs::Mercenaries, "SendMercPersonalInfo Request for %s.", GetName());
 			SendMercPersonalInfo();
 		}
 		else
 		{
-			Log(Logs::General, Logs::Mercenaries, "SendMercPersonalInfo Not Sent - MercID (%i) for %s.", GetMercInfo().mercid, GetName());
+			Log(Logs::General, Logs::Mercenaries, "SendMercPersonalInfo Not Sent - no mercs owned for %s.", GetName());
 		}
 	}
 
@@ -10761,6 +10759,88 @@ void Client::Handle_OP_MercenarySuspendRequest(const EQApplicationPacket *app)
 	SuspendMercCommand();
 }
 
+void Client::Handle_OP_MercenarySwitch(const EQApplicationPacket *app)
+{
+	if (app->size != sizeof(SwitchMercenary_Struct)) {
+		LogDebug("Size mismatch in OP_MercenarySwitch expected [{}] got [{}]", sizeof(SwitchMercenary_Struct), app->size);
+		DumpPacket(app);
+		return;
+	}
+
+	if (!RuleB(Mercs, AllowMercs))
+		return;
+
+	SwitchMercenary_Struct* sm = (SwitchMercenary_Struct*)app->pBuffer;
+	uint32 merc_ui_index = sm->MercIndex;
+
+	Log(Logs::General, Logs::Mercenaries, "Switch request to UI index %u received from %s.", merc_ui_index, GetName());
+
+	// The client sends a dense UI index (0, 1, 2...) that corresponds to the Nth
+	// owned merc in the list, matching the order sent by SendMercPersonalInfo().
+	// SendMercPersonalInfo emits the active slot first, then remaining slots in order.
+	// We must replicate that same ordering to map UI index -> internal slot.
+	int target_slot = -1;
+	int max_slots = std::min(RuleI(Mercs, MaxMercSlots), MAXMERCS);
+	uint32 ui_pos = 0;
+
+	// First: the active merc slot (emitted first in the packet)
+	if (GetMercSlot() < max_slots && m_mercinfo[GetMercSlot()].mercid != 0) {
+		if (ui_pos == merc_ui_index) {
+			target_slot = GetMercSlot();
+		}
+		ui_pos++;
+	}
+
+	// Then: remaining slots in order (skipping active slot)
+	if (target_slot < 0) {
+		for (int slot = 0; slot < max_slots; slot++) {
+			if (slot == GetMercSlot()) {
+				continue;
+			}
+			if (m_mercinfo[slot].mercid != 0) {
+				if (ui_pos == merc_ui_index) {
+					target_slot = slot;
+					break;
+				}
+				ui_pos++;
+			}
+		}
+	}
+
+	if (target_slot < 0) {
+		Log(Logs::General, Logs::Mercenaries, "Switch request denied — UI index %u has no corresponding merc for %s.", merc_ui_index, GetName());
+		SendMercResponsePackets(0);
+		return;
+	}
+
+	if (target_slot == GetMercSlot()) {
+		Log(Logs::General, Logs::Mercenaries, "Switch request ignored — already on slot %i for %s.", target_slot, GetName());
+		return;
+	}
+
+	// Suspend the currently active merc if one is spawned
+	Merc* current_merc = GetMerc();
+	if (current_merc) {
+		current_merc->Suspend();
+		// Clear merc pointer without wiping slot data (SetMerc(nullptr) would zero the slot)
+		current_merc->SetOwnerID(0);
+		SetMercID(0);
+	}
+
+	// Clear the suspend timer so the target merc can be unsuspended immediately.
+	// The cooldown is meant for rapid suspend/unsuspend of the same merc, not for switching.
+	if (!GetPTimers().Expired(&database, pTimerMercSuspend, false)) {
+		GetPTimers().Clear(&database, pTimerMercSuspend);
+	}
+
+	SetMercSlot(static_cast<uint8>(target_slot));
+
+	Log(Logs::General, Logs::Mercenaries, "Switched active merc slot to %i (UI index %u) for %s.", target_slot, merc_ui_index, GetName());
+
+	// Unsuspend the target merc
+	SuspendMercCommand();
+}
+
 void Client::Handle_OP_MercenaryTimerRequest(const EQApplicationPacket *app)
 {
 	// The payload is 0 bytes.

zone/client_packet.h

@@ -239,6 +239,7 @@
 	void Handle_OP_MercenaryDismiss(const EQApplicationPacket *app);
 	void Handle_OP_MercenaryHire(const EQApplicationPacket *app);
 	void Handle_OP_MercenarySuspendRequest(const EQApplicationPacket *app);
+	void Handle_OP_MercenarySwitch(const EQApplicationPacket *app);
 	void Handle_OP_MercenaryTimerRequest(const EQApplicationPacket *app);
 	void Handle_OP_MoveCoin(const EQApplicationPacket *app);
 	void Handle_OP_MoveItem(const EQApplicationPacket *app);