Int21 bug

[Valentijn Sessink]

Hi folks,

I think I hunted down a bug in DOS int21 function 0x5b (my DOS book insists
this is 91 decimal). My older version of wine, 2000821, goes like this:

trace:int21:DOS3Call CREATE NEW FILE 0x00 for X:\TMP41.$$$
trace:file:CreateFileA X:\TMP41.$$$ GENERIC_READ GENERIC_WRITE FILE_SHARE_READ FILE_SHARE_WRITE CREATE_NEW
trace:dosfs:DOSFS_GetFullName X:\TMP41.$$$ (last=0)
trace:string:lstrcpynA (0x40e35fa0, "/tmp", 1024)
trace:dosfs:DOSFS_FindUnixName /tmp,TMP41.$$$
trace:heap:HeapAlloc (403c0000,00000002,0000022c): returning 414c9cf4
trace:heap:HeapAlloc (65430000,04000000,00000018): returning 65432c30
warn:dosfs:DOSFS_FindUnixName 'TMP41.$$$' not found in '/tmp'
trace:heap:HeapFree (65430000,04000000,65432c30): returning TRUE
trace:heap:HeapFree (403c0000,00000002,414c9cf4): returning TRUE
trace:dosfs:DOSFS_GetFullName returning /tmp/TMP41.$$$ = X:\tmp41.$$$
080732c8: create_file( access=c0000000, inherit=0, sharing=00000003, create=1, attrs=00000000, filename="/tmp/TMP41.$$$" )
080732c8: create_file() = 0 { handle=136 }
trace:file:FILE_AllocDosHandle Got 10 for h32 136
trace:int21:DOS3Call returning: AX=000a BX=5b0c CX=0000 DX=e9a8 SI=0000 DI=e9a8 DS=0a27 ES=0907 EFL=00000202
trace:global:GlobalHandle16 0107
Ret  KERNEL.102: DOS3CALL() retval=none ret=0347:2513 ds=0a27
     AX=000a BX=5b0c CX=0000 DX=e9a8 SI=0000 DI=e9a8 ES=0907 EFL=00000202
trace:global:GlobalHandle16 0107

So: file handle 0x136 translates to DOS handle 10, and int21 returns AX=0x000a

My newer version, Wine 20030408, does the following:

000a:trace:int21:INT_Int21Handler CREATE NEW FILE 0x00 for X:\TMP18467.$$$
000a:trace:heap:RtlAllocateHeap (0x40370000,00000002,00000020): returning 415b32c0
000a:trace:file:CreateFileW L"X:\\TMP18467.$$$" GENERIC_READ GENERIC_WRITE FILE_SHARE_READ FILE_SHARE_WRITE CREATE_NEW attributes 0x0
000a:trace:dosfs:DOSFS_GetFullName L"X:\\TMP18467.$$$" (last=0)
000a:trace:string:lstrcpynA (0x40f40d84, "/tmp", 1024)
000a:trace:dosfs:DOSFS_FindUnixName /tmp,L"TMP18467.$$$"
000a:trace:dosfs:DOSFS_ToDosFCBFormat (L"TMP18467.$$$", 0x40f40ce4)
000a:trace:heap:RtlAllocateHeap (0x40370000,00000002,00000110): returning 415cc890
000a:trace:dosfs:DOSFS_OpenDir "/tmp"
000a:trace:heap:RtlAllocateHeap (0x40370000,00000002,00000018): returning 415cbca0
000a:trace:heap:RtlReAllocateHeap (0x40370000,00000002,415cc890,00000210): returning 415cc890
000a:trace:heap:RtlReAllocateHeap (0x40370000,00000002,415cc890,00000410): returning 415cc890
000a:trace:heap:RtlReAllocateHeap (0x40370000,00000002,415cc890,00000810): returning 415cc890
000a:trace:heap:RtlReAllocateHeap (0x40370000,00000002,415cc890,00001010): returning 415cc890
000a:trace:heap:RtlFreeHeap (0x40370000,00000002,415cbca0): returning TRUE
000a:trace:dosfs:DOSFS_ReadDir Read: long_name: L".", short_name: (null)
000a:trace:dosfs:DOSFS_ReadDir Read: long_name: L"..", short_name: (null)
000a:trace:dosfs:DOSFS_ReadDir Read: long_name: L".font-unix", short_name: (null)
           [cut directory listing]
000a:warn:dosfs:DOSFS_FindUnixName L"TMP18467.$$$" not found in '/tmp'
000a:trace:heap:RtlFreeHeap (0x40370000,00000002,415cc890): returning TRUE
000a:trace:dosfs:DOSFS_GetFullName returning /tmp/TMP18467.$$$ = L"X:\\tmp18467.$$$"
000a:trace:dosfs:GetDriveTypeW (L"X:\\tmp18467.$$$")
000a: create_file( access=c0000000, inherit=0, sharing=00000003, create=1, attrs=00000000, drive_type=3, filename="/tmp/TMP18467.$$$" )
000a: create_file() = 0 { handle=0x98 }
000a:trace:file:CreateFileW returning 0x98
000a:trace:heap:RtlFreeHeap (0x40370000,00000002,415b32c0): returning TRUE
000a:trace:file:Win32HandleToDosFileHandle Got 10 for h32 0x98
000a:Ret  kernel32.INT_Int21Handler() retval=00000000 ret=41560c39
000a:trace:int21:DOSVM_Int21Handler failed, error 0
000a:trace:int21:DOSVM_Int21Handler returning: AX=0000 BX=5b0f CX=0000 DX=e9a8 SI=0000 DI=e9a8 DS=0a47 ES=0927 EFL=00000203
000a:Ret  winedos.CallBuiltinHandler() retval=0000007c ret=4008d9f0
000a:trace:global:GlobalHandle16 011f

This seems weird: there's a file handle, there's a DOS file handle but Int21
returns AX=0, indicating an error.

I did not yet check the code (will do this afternoon, but beware: I'm not
much of a coder), but I think a fix should be rather easy, there's probably
just a typo (or a thinko) in the Int21 handler.

I'm not sure, but this bug could also help number 1170, that seems related
in that there's a file that is not actually there, and 717, which also tries
to make a file that isn't created.

Please Cc: my e-mail-address as I'm not on the Wine-devel list. the "nospam"
part has an MX record, so mailing shouldn't be a problem.

We also checked Codeweavers Wine for this bug; it seems to be there, but
after two days of bug hunting our hunting ground is a bit of a mess, so I'm
not sure if we tested 2.0 or 2.1. I searched Bugzilla for a DOS related bug
and couldn't find one, but if it's fixed between 20030408 and now, then
please accept my apologies for wasting your precious reading time.

Best regards,

Valentijn