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[BUG/PRB.] VFP 9.0 FIX - SQLSETPROP() FUNCTION
January 2024
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CCB
1. BUG:
In vfp9 (and vfp6, vfp7, vfp8), sometimes the SQLSETPROP(0,"Transactions",1) function causes the error "Connection 0# is busy (Error 1541)".
The bug only occurs on some Windows versions or some ODBC drivers.
2. CAUSE:
There are some BUGs in the following code.
3. RESOLUTION:
We can write some code to fix the BUG.
Fun882c46 :: ; proc near
push ebp ;0x00882c46 : 55
mov ebp , esp ;0x00882c47 : 8bec
sub esp , 0104h ;0x00882c49 : 81ec04010000
mov eax , dword ptr [ Data937090 ] ;0x00882c4f : a190709300
push esi ;0x00882c54 : 56
mov esi , dword ptr [ ebp + 8 ] ;0x00882c55 : 8b7508
imul esi , esi , 0158h ;0x00882c58 : 69f658010000
mov dword ptr [ ebp - 4 ] , eax ;0x00882c5e : 8945fc
mov eax , dword ptr [ Data93b94c ] ;0x00882c61 : a14cb99300
mov ecx , dword ptr [eax] ;0x00882c66 : 8b08
mov cl , byte ptr [ esi + ecx + 65 ] ;0x00882c68 : 8a4c0e41
test cl , cl ;0x00882c6c : 84c9
je Label882cba ;0x00882c6e : 744a
movzx ecx , cl ;0x00882c70 : 660fb6c9
cmp cx , word ptr [ ebp + 12 ] ;0x00882c74 : 663b4d0c
je Label882cba ;0x00882c78 : 7440
and dword ptr [ebx] , 00h ;0x00882c7a : 832300
mov eax , dword ptr [eax] ;0x00882c7d : 8b00
mov al , byte ptr [ esi + eax + 65 ] ;0x00882c7f : 8a440641
cmp al , 01h ;0x00882c83 : 3c01
jne Label882c8e ;0x00882c85 : 7507
mov ecx , 01DAh ;0x00882c87 : b9da010000
jmp Label882cb5 ;0x00882c8c : eb27
Label882c8e ::
cmp al , 02h ;0x00882c8e : 3c02
jne Label882c99 ;0x00882c90 : 7507
mov ecx , 01DBh ;0x00882c92 : b9db010000
jmp Label882cb5 ;0x00882c97 : eb1c
Label882c99 ::
cmp al , 03h ;0x00882c99 : 3c03
jne Label882ca4 ;0x00882c9b : 7507
mov ecx , 01DCh ;0x00882c9d : b9dc010000
jmp Label882cb5 ;0x00882ca2 : eb11
Label882ca4 ::
xor ecx , ecx ;0x00882ca4 : 33c9
cmp al , 04h ;0x00882ca6 : 3c04
setne cl ;0x00882ca8 : 0f95c1
dec ecx ;0x00882cab : 49
and ecx , 0Ch ;0x00882cac : 83e10c
add ecx , 01D1h ;0x00882caf : 81c1d1010000
Label882cb5 ::
call Fun544742 ;0x00882cb5 : e8881accff
Label882cba ::
mov dword ptr [ebx] , 01h ;0x00882cba : c70301000000
cmp word ptr [ ebp + 12 ] , 02h ;0x00882cc0 : 66837d0c02
je Label882cd8 ;0x00882cc5 : 7411
mov ecx , dword ptr [eax] ;0x00882cc7 : 8b08
lea edx , dword ptr [ esi + ecx ] ;0x00882cc9 : 8d140e
cmp dword ptr [ edx + 48 ] , 00h ;0x00882ccc : 837a3000
je Label882cd8 ;0x00882cd0 : 7406
test byte ptr [ edx + 16 ] , 02h ;0x00882cd2 : f6421002
jne Label882ce3 ;0x00882cd6 : 750b
Label882cd8 ::
mov eax , dword ptr [eax] ;0x00882cd8 : 8b00
lea edx , dword ptr [ esi + eax ] ;0x00882cda : 8d1406
test byte ptr [ edx + 17 ] , 08h ;0x00882cdd : f6421108
je Label882d56 ;0x00882ce1 : 7473
Label882ce3 ::
;
; -------------------------------------------------
; VFP 9.0 FIX - SQLSETPROP() FUNCTION
; August 2019
; -------------------------------------------------
; CCB
;
; Sometimes the SQLSETPROP(0,"Transactions",1) function causes the error "Connection 0# is busy (Error 1541)".
;
; 2019/8/30, by ccb
;
cmp dword ptr [ ebp + 8 ] , 00h
je Label882d56
push edi ;0x00882ce3 : 57
xor eax , eax ;0x00882ce4 : 33c0
pushd 03Fh ;0x00882ce6 : 6a3f
mov byte ptr [ ebp + 0FFFFFEFCh ] , 00h ;0x00882ce8 : c685fcfeffff00
pop ecx ;0x00882cef : 59
lea edi , dword ptr [ ebp + 0FFFFFEFDh ] ;0x00882cf0 : 8dbdfdfeffff
rep stosd ;0x00882cf6 : f3ab
mov ecx , dword ptr [ Data93b948 ] ;0x00882cf8 : 8b0d48b99300
mov ecx , dword ptr [ecx] ;0x00882cfe : 8b09
stosw ;0x00882d00 : 66ab
mov edx , dword ptr [edx] ;0x00882d02 : 8b12
lea eax , dword ptr [ edx + 2 * edx ] ;0x00882d04 : 8d0452
shl eax , 05h ;0x00882d07 : c1e005
mov eax , dword ptr [ eax + ecx + 56 ] ;0x00882d0a : 8b440838
test eax , eax ;0x00882d0e : 85c0
pop edi ;0x00882d10 : 5f
je Label882d27 ;0x00882d11 : 7414
mov ecx , dword ptr [eax] ;0x00882d13 : 8b08
mov edx , 0FFh ;0x00882d15 : baff000000
lea eax , dword ptr [ ebp + 0FFFFFEFCh ] ;0x00882d1a : 8d85fcfeffff
call Fun42c33e ;0x00882d20 : e81996baff
jmp Label882d3e ;0x00882d25 : eb17
Label882d27 ::
push dword ptr [ ebp + 8 ] ;0x00882d27 : ff7508
lea eax , dword ptr [ ebp + 0FFFFFEFCh ] ;0x00882d2a : 8d85fcfeffff
pushd offset Data92ac70 ;0x00882d30 : 6870ac9200
push eax ;0x00882d35 : 50
call Fun43089c ;0x00882d36 : e861dbbaff
add esp , 0Ch ;0x00882d3b : 83c40c
Label882d3e ::
and dword ptr [ebx] , 00h ;0x00882d3e : 832300
lea eax , dword ptr [ ebp + 0FFFFFEFCh ] ;0x00882d41 : 8d85fcfeffff
call Fun4ba8ba ;0x00882d47 : e86e7bc3ff
mov ecx , 021Dh ;0x00882d4c : b91d020000
call Fun544742 ;0x00882d51 : e8ec19ccff
Label882d56 ::
mov ecx , dword ptr [ ebp - 4 ] ;0x00882d56 : 8b4dfc
pop esi ;0x00882d59 : 5e
call Fun42bf1d ;0x00882d5a : e8be91baff
leave ;0x00882d5f : c9
ret 08h ;0x00882d60 : c20800
4. APPLIES TO:
VFP 6.0.8167.0
VFP 6.0.8961.0 (SP5)
VFP 7.0.0.9262
VFP 7.0.0.9465 (SP1)
VFP 8.0.0.2521
VFP 8.0.0.3117 (SP1)
VFP 9.0.0.2412
VFP 9.0.0.3504 (SP1)
VFP 9.0.0.4611 (SP2)
VFP 9.0.0.5015 (SP2)
VFP 9.0.0.5411 (SP2)
VFP 9.0.0.5721 (SP2)
VFP 9.0.0.5815 (SP2)
VFP 9.0.0.6303 (SP2)
VFP 9.0.0.6602 (SP2)
VFP 9.0.0.7423 (SP2)
The bug has been fixed in VFP Advanced.
5. REFERENCE WEBSITES:
1, baiyujia.com:
http://www.baiyujia.com
2, microsoft.com:
https://social.msdn.microsoft.com/forums/en-US/41f0cff8-202b-4fb5-8d84-7295249c9261/connection-0-is-busy
3, tek-tips.com:
https://www.tek-tips.com/viewthread.cfm?qid=1746276
6. OTHER:
For reference only, there is no guarantees.
Any questions or suggestions, please send me an email at ccb2000@163.com.
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