test: add unit tests for cherry-pick impacted handlers

Add comprehensive tests documenting current behavior before applying
fixes from main branch. Tests cover:

- Cafe item PointCost parsing (uint32 vs uint16 for different client modes)
- Guild poogie outfit unlock calculation bug (math.Pow issue)
- Guild manage right nil pointer condition (&& vs || logic)
- InfoGuild applicant GR field size for <G10 clients
- Stage binary wait infinite loop risk (no timeout)
- Entrance server hardcoded clan member limit

network/mhfpacket/msg_mhf_acquire_cafe_item_test.go

@@ -0,0 +1,172 @@
+package mhfpacket
+
+import (
+	"io"
+	"testing"
+
+	"erupe-ce/common/byteframe"
+	"erupe-ce/network"
+	"erupe-ce/network/clientctx"
+)
+
+func TestMsgMhfAcquireCafeItemOpcode(t *testing.T) {
+	pkt := &MsgMhfAcquireCafeItem{}
+	if pkt.Opcode() != network.MSG_MHF_ACQUIRE_CAFE_ITEM {
+		t.Errorf("Opcode() = %s, want MSG_MHF_ACQUIRE_CAFE_ITEM", pkt.Opcode())
+	}
+}
+
+func TestMsgMhfAcquireCafeItemParse(t *testing.T) {
+	// Test basic parsing with current implementation (always reads uint32 for PointCost)
+	// Current code: m.PointCost = bf.ReadUint32() (no client mode check)
+	bf := byteframe.NewByteFrame()
+	bf.WriteUint32(0x12345678) // AckHandle
+	bf.WriteUint16(1)          // ItemType
+	bf.WriteUint16(100)        // ItemID
+	bf.WriteUint16(5)          // Quant
+	bf.WriteUint32(1000)       // PointCost (uint32)
+	bf.WriteUint16(0)          // Unk0
+
+	bf.Seek(0, io.SeekStart)
+
+	pkt := &MsgMhfAcquireCafeItem{}
+	ctx := &clientctx.ClientContext{}
+
+	err := pkt.Parse(bf, ctx)
+	if err != nil {
+		t.Fatalf("Parse() error = %v", err)
+	}
+
+	if pkt.AckHandle != 0x12345678 {
+		t.Errorf("AckHandle = 0x%X, want 0x12345678", pkt.AckHandle)
+	}
+	if pkt.ItemType != 1 {
+		t.Errorf("ItemType = %d, want 1", pkt.ItemType)
+	}
+	if pkt.ItemID != 100 {
+		t.Errorf("ItemID = %d, want 100", pkt.ItemID)
+	}
+	if pkt.Quant != 5 {
+		t.Errorf("Quant = %d, want 5", pkt.Quant)
+	}
+	if pkt.PointCost != 1000 {
+		t.Errorf("PointCost = %d, want 1000", pkt.PointCost)
+	}
+}
+
+// TestMsgMhfAcquireCafeItemParseUint32PointCost documents the current behavior.
+//
+// CURRENT BEHAVIOR: Always reads PointCost as uint32.
+//
+// EXPECTED BEHAVIOR AFTER FIX (commit 3d0114c):
+// - G6+: Read PointCost as uint32
+// - G1-G5.2: Read PointCost as uint16
+//
+// This test verifies current uint32 parsing works correctly.
+// After the fix is applied, this test should still pass for G6+ clients.
+func TestMsgMhfAcquireCafeItemParseUint32PointCost(t *testing.T) {
+	tests := []struct {
+		name      string
+		pointCost uint32
+		wantCost  uint32
+	}{
+		{"small cost", 100, 100},
+		{"medium cost", 5000, 5000},
+		{"large cost exceeding uint16", 70000, 70000},
+		{"max uint32", 0xFFFFFFFF, 0xFFFFFFFF},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			bf := byteframe.NewByteFrame()
+			bf.WriteUint32(0xAAAABBBB) // AckHandle
+			bf.WriteUint16(1)          // ItemType
+			bf.WriteUint16(200)        // ItemID
+			bf.WriteUint16(10)         // Quant
+			bf.WriteUint32(tt.pointCost)
+			bf.WriteUint16(0) // Unk0
+
+			bf.Seek(0, io.SeekStart)
+
+			pkt := &MsgMhfAcquireCafeItem{}
+			ctx := &clientctx.ClientContext{}
+
+			err := pkt.Parse(bf, ctx)
+			if err != nil {
+				t.Fatalf("Parse() error = %v", err)
+			}
+
+			if pkt.PointCost != tt.wantCost {
+				t.Errorf("PointCost = %d, want %d", pkt.PointCost, tt.wantCost)
+			}
+		})
+	}
+}
+
+// TestMsgMhfAcquireCafeItemParseFieldOrder verifies the exact field order in parsing.
+// This is important because the fix changes when PointCost is read (uint16 vs uint32).
+func TestMsgMhfAcquireCafeItemParseFieldOrder(t *testing.T) {
+	// Build a packet with known values
+	bf := byteframe.NewByteFrame()
+	bf.WriteUint32(0x11223344) // AckHandle (offset 0-3)
+	bf.WriteUint16(0x5566)     // ItemType (offset 4-5)
+	bf.WriteUint16(0x7788)     // ItemID (offset 6-7)
+	bf.WriteUint16(0x99AA)     // Quant (offset 8-9)
+	bf.WriteUint32(0xBBCCDDEE) // PointCost (offset 10-13)
+	bf.WriteUint16(0xFF00)     // Unk0 (offset 14-15)
+
+	bf.Seek(0, io.SeekStart)
+
+	pkt := &MsgMhfAcquireCafeItem{}
+	err := pkt.Parse(bf, &clientctx.ClientContext{})
+	if err != nil {
+		t.Fatalf("Parse() error = %v", err)
+	}
+
+	if pkt.AckHandle != 0x11223344 {
+		t.Errorf("AckHandle = 0x%X, want 0x11223344", pkt.AckHandle)
+	}
+	if pkt.ItemType != 0x5566 {
+		t.Errorf("ItemType = 0x%X, want 0x5566", pkt.ItemType)
+	}
+	if pkt.ItemID != 0x7788 {
+		t.Errorf("ItemID = 0x%X, want 0x7788", pkt.ItemID)
+	}
+	if pkt.Quant != 0x99AA {
+		t.Errorf("Quant = 0x%X, want 0x99AA", pkt.Quant)
+	}
+	if pkt.PointCost != 0xBBCCDDEE {
+		t.Errorf("PointCost = 0x%X, want 0xBBCCDDEE", pkt.PointCost)
+	}
+	if pkt.Unk0 != 0xFF00 {
+		t.Errorf("Unk0 = 0x%X, want 0xFF00", pkt.Unk0)
+	}
+}
+
+func TestMsgMhfAcquireCafeItemBuildNotImplemented(t *testing.T) {
+	pkt := &MsgMhfAcquireCafeItem{
+		AckHandle: 123,
+		ItemType:  1,
+		ItemID:    100,
+		Quant:     5,
+		PointCost: 1000,
+	}
+
+	bf := byteframe.NewByteFrame()
+	ctx := &clientctx.ClientContext{}
+
+	err := pkt.Build(bf, ctx)
+	if err == nil {
+		t.Error("Build() should return error (NOT IMPLEMENTED)")
+	}
+}
+
+func TestMsgMhfAcquireCafeItemFromOpcode(t *testing.T) {
+	pkt := FromOpcode(network.MSG_MHF_ACQUIRE_CAFE_ITEM)
+	if pkt == nil {
+		t.Fatal("FromOpcode(MSG_MHF_ACQUIRE_CAFE_ITEM) returned nil")
+	}
+	if pkt.Opcode() != network.MSG_MHF_ACQUIRE_CAFE_ITEM {
+		t.Errorf("Opcode() = %s, want MSG_MHF_ACQUIRE_CAFE_ITEM", pkt.Opcode())
+	}
+}