Verify that we match ddnet in 0.6 chunk header packing

src/chunk_packer6.asm

@@ -51,8 +51,10 @@ pack_chunk_header6:
     ; if sequence is bigger than 8 bit
     mov r8, 0
     mov r8d, dword [connection_sequence]
-    shr r8, 2
-    and r8, 0b11110000
+    shr r8b, 2
+    and r8b, 0b11110000
+    ; teeworlds uses 11110000
+    ; and ddnet uses 11111100
     or byte [rsi+1], r8b
 
     ; full 8 bit sequence into third byte

tests/chunk6_test.asm

@@ -26,28 +26,24 @@ test_pack_chunk_header6_size23_seq3:
     mov al, [assert_actual_buf + 2]
     assert_al_eq 0x03, __LINE__
 
+test_pack_chunk_header6_size0_seqFF:
+    mov dword [connection_sequence], 255
 
-; test_pack_chunk_header6_size6_seq65:
-;     mov dword [connection_sequence], 65
-; 
-;     ; tested with twnet_parser
-;     ; header: ChunkHeader = parser.parse_header6(b'\x40\x16\x01')
-;     ; assert header.flags.resend is False
-;     ; assert header.flags.vital is True
-;     ; assert header.size == 6
-;     ; assert header.seq == 65
-; 
-;     mov rax, 0
-;     set_rax_flag CHUNKFLAG_VITAL
-;     mov rdi, 6
-;     mov rsi, assert_actual_buf
-;     call pack_chunk_header6
-; 
-;     mov al, [assert_actual_buf]
-;     assert_al_eq 0x40, __LINE__
-;     mov al, [assert_actual_buf + 1]
-;     assert_al_eq 0x16, __LINE__
-;     mov al, [assert_actual_buf + 2]
-;     assert_al_eq 0x01, __LINE__
+    ; does not match twnet_parser
+    ; but twnet_parser might be "wrong" in that case
+    ; see https://gitlab.com/teeworlds-network/twnet_parser/-/commit/52a66b5eebc0b337f2eb30cf4cffbe55af63c85f
+    mov rax, 0
+    set_rax_flag CHUNKFLAG_VITAL
+    mov rdi, 0 ; size
+    mov rsi, assert_actual_buf
+    call pack_chunk_header6
+
+    mov al, [assert_actual_buf]
+    assert_al_eq 0x40, __LINE__
+
+    mov al, [assert_actual_buf + 1]
+    assert_al_eq 0x30, __LINE__ ; this is weird but matches ddnet https://github.com/ddnet/ddnet/pull/9417
+    mov al, [assert_actual_buf + 2]
+    assert_al_eq 0xff, __LINE__
 
     end_test __LINE__