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[BUG/PRB.] VFP 9.0 FIX - SYS(2017) FUNCTION
January 2024
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CCB
1. BUG:
In vfp9 and vfp8, sometimes vfp will crash when calling the SYS(2017) function with a memo field.
There is a test program:
*PROC testsys2017function
SELE 0
CREATE CURSOR tmp1 (fld1 m)
APPEND BLANK
REPL fld1 WITH "aaa"
?INLIST("123","a","b","c",SYS(2017,fld1))
WAIT
RETURN
* END OF PROC TESTSYS2017FUNCTION.
We think it will display .F., but vfp will crash.
2. CAUSE:
There are some BUGs in the following code.
3. RESOLUTION:
We can write some code to fix the BUG.
Fun4a487b :: ; proc near
push ebp ;0x004a487b : 55
lea ebp , dword ptr [ esp + 0FFFFFBC0h ] ;0x004a487c : 8dac24c0fbffff
sub esp , 04C0h ;0x004a4883 : 81ecc0040000
test byte ptr [ ebp + 0450h ] , 01h ;0x004a4889 : f6855004000001
mov eax , dword ptr [ Data937090 ] ;0x004a4890 : a190709300
push ebx ;0x004a4895 : 53
mov ebx , dword ptr [ ebp + 0448h ] ;0x004a4896 : 8b9d48040000
push esi ;0x004a489c : 56
mov esi , dword ptr [ ebp + 044Ch ] ;0x004a489d : 8bb54c040000
mov dword ptr [ ebp + 043Ch ] , eax ;0x004a48a3 : 89853c040000
push edi ;0x004a48a9 : 57
jne Label5a64c1 ;0x004a48aa : 0f85111c1000
pushd 08h ;0x004a48b0 : 6a08
call Fun437a96 ;0x004a48b2 : e8df31f9ff
test esi , esi ;0x004a48b7 : 85f6
pop ecx ;0x004a48b9 : 59
jne Label5a64e0 ;0x004a48ba : 0f85201c1000
test eax , eax ;0x004a48c0 : 85c0
je Label4a4925 ;0x004a48c2 : 7461
mov dword ptr [eax] , offset DataPtr91fbe0 ;0x004a48c4 : c700e0fb9100
or word ptr [ eax + 4 ] , 0FFFFFFFFh ;0x004a48ca : 66834804ff
Label4a48cf ::
mov dword ptr [ ebp + 16 ] , eax ;0x004a48cf : 894510
Label4a48d2 ::
test byte ptr [ ebp + 0450h ] , 080h ;0x004a48d2 : f6855004000080
jne Label5a6544 ;0x004a48d9 : 0f85651c1000
mov al , byte ptr [ebx] ;0x004a48df : 8a03
cmp al , 04Dh ;0x004a48e1 : 3c4d
je Label4a492b ;0x004a48e3 : 7446
cmp al , 057h ;0x004a48e5 : 3c57
je Label4a492b ;0x004a48e7 : 7442
push dword ptr [ ebx + 8 ] ;0x004a48e9 : ff7308
mov edx , dword ptr [ ebx + 32 ] ;0x004a48ec : 8b5320
mov ecx , dword ptr [ ebp + 16 ] ;0x004a48ef : 8b4d10
push dword ptr [edx] ;0x004a48f2 : ff32
mov eax , dword ptr [ecx] ;0x004a48f4 : 8b01
call dword ptr [eax] ;0x004a48f6 : ff10
Label4a48f8 ::
mov edi , dword ptr [ ebp + 16 ] ;0x004a48f8 : 8b7d10
mov eax , dword ptr [edi] ;0x004a48fb : 8b07
mov ecx , edi ;0x004a48fd : 8bcf
call dword ptr [ eax + 4 ] ;0x004a48ff : ff5004
push edi ;0x004a4902 : 57
mov esi , eax ;0x004a4903 : 8bf0
call Fun43d8b4 ;0x004a4905 : e8aa8ff9ff
pop ecx ;0x004a490a : 59
mov eax , esi ;0x004a490b : 8bc6
Label4a490d ::
mov ecx , dword ptr [ ebp + 043Ch ] ;0x004a490d : 8b8d3c040000
call Fun42bf1d ;0x004a4913 : e80576f8ff
pop edi ;0x004a4918 : 5f
pop esi ;0x004a4919 : 5e
pop ebx ;0x004a491a : 5b
add ebp , 0440h ;0x004a491b : 81c540040000
leave ;0x004a4921 : c9
ret 0Ch ;0x004a4922 : c20c00
Label5a6544 ::
;
; -------------------------------------------------
; VFP 9.0 FIX - SYS(2017) FUNCTION
; March 2021
; -------------------------------------------------
; CCB
;
; Sometimes vfp will crash when calling the SYS(2017) function with a memo field.
;
; 2021/3/28, by ccb
;
xor eax , eax
xor esi , esi
cmp ebx , esi
je Label4a490d
mov al , byte ptr [ebx]
cmp al , 04Dh
je Label4a48f8
pushd 0Bh ;0x005a6544 : 6a0b
xor eax , eax ;0x005a6546 : 33c0
xor esi , esi ;0x005a6548 : 33f6
cmp ebx , esi ;0x005a654a : 3bde
pop ecx ;0x005a654c : 59
lea edi , dword ptr [ ebp - 44 ] ;0x005a654d : 8d7dd4
rep stosd ;0x005a6550 : f3ab
je Label5a657a ;0x005a6552 : 7426
mov edi , dword ptr [ ebx + 8 ] ;0x005a6554 : 8b7b08
mov eax , 0100h ;0x005a6557 : b800010000
cmp edi , eax ;0x005a655c : 3bf8
jbe Label5a6562 ;0x005a655e : 7602
mov edi , eax ;0x005a6560 : 8bf8
Label5a6562 ::
mov eax , dword ptr [ ebx + 32 ] ;0x005a6562 : 8b4320
push edi ;0x005a6565 : 57
push dword ptr [eax] ;0x005a6566 : ff30
lea eax , dword ptr [ ebp + 013Ch ] ;0x005a6568 : 8d853c010000
push eax ;0x005a656e : 50
call dword ptr [ Data9392b8 ] ;0x005a656f : ff15b8929300
add esp , 0Ch ;0x005a6575 : 83c40c
jmp Label5a657c ;0x005a6578 : eb02
4. APPLIES TO:
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
http://www.baiyujia.com/vfpdocuments/f_vfpsysfunctions.asp
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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