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[BUG/PRB.] VFP 9.0 FIX - FIX THE POINTER OF P-CODE FOR THE ROWSOURCE PROPERTY
January 2024
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CCB
1. BUG:
In VFP 9.0 and earlier versions, for the ComboBox control and the ListBox control,
if we set the RowSourceType property to 2 (Table alias) or 6 (Fields),
sometimes it causes the error "Expression evaluator failed (Error 67)".
The bug occurs in vfp7, vfp8 and vfp9, it does not occur in vfp6.
The bug only occurs when !ORDER()=="" (SET ORDER TO TagName), it does not occur when ORDER()=="" (SET ORDER TO).
2. CAUSE:
In VFP 9.0 and earlier versions, for example,
if we set ComboBox.RowSourceType = 6 (Fields) and ComboBox.RowSource = "table1.fld1",
the RowSource property "table1.fld1" will be compiled to the p-code (total 9 bytes):
FC F4 68 03 F7 6D 03 FD FE ?? ?? ?? ?? ?? ?? ??
-----------------------------------------------
sometimes the pointer of p-code points to the end of the p-code (the 10th byte: ??),
if the 10th byte is 0x1E (NEXT nRecords) or 0x23 (RECORD nRecordNumber),
it causes the error "Expression evaluator failed (Error 67)".
There are some BUGs in the following code.
3. RESOLUTION:
We can write some code to fix the BUG.
Fun45732d :: ; proc near
push ebp ;0x0045732d : 55
mov ebp , esp ;0x0045732e : 8bec
sub esp , 068h ;0x00457330 : 83ec68
push ebx ;0x00457333 : 53
push esi ;0x00457334 : 56
push edi ;0x00457335 : 57
pushd 0180Ch ;0x00457336 : 680c180000
mov eax , 0260h ;0x0045733b : b860020000
call Fun42bf2a ;0x00457340 : e8e54bfdff
mov ecx , dword ptr [eax] ;0x00457345 : 8b08
mov edx , dword ptr [ ebp + 8 ] ;0x00457347 : 8b5508
mov dword ptr [ ecx + 4 ] , 04h ;0x0045734a : c7410404000000
mov ecx , dword ptr [eax] ;0x00457351 : 8b08
xor ebx , ebx ;0x00457353 : 33db
mov dword ptr [ ecx + 0258h ] , ebx ;0x00457355 : 899958020000
mov ecx , dword ptr [ Data9370f8 ] ;0x0045735b : 8b0df8709300
mov dword ptr [ ebp - 8 ] , eax ;0x00457361 : 8945f8
mov eax , dword ptr [eax] ;0x00457364 : 8b00
mov dword ptr [ eax + 20 ] , ecx ;0x00457366 : 894814
mov ecx , dword ptr [ edx + 0140h ] ;0x00457369 : 8b8a40010000
mov edx , 01h ;0x0045736f : ba01000000
call Fun42f404 ;0x00457374 : e88b80fdff
mov eax , dword ptr [eax] ;0x00457379 : 8b00
or byte ptr [ eax + 4 ] , 01h ;0x0045737b : 80480401
mov eax , dword ptr [ Data9393ac ] ;0x0045737f : a1ac939300
mov dword ptr [ ebp - 16 ] , eax ;0x00457384 : 8945f0
lea edx , dword ptr [ ebp - 12 ] ;0x00457387 : 8d55f4
lea eax , dword ptr [ ebp - 100 ] ;0x0045738a : 8d459c
call Fun42c27f ;0x0045738d : e8ed4efdff
push ebx ;0x00457392 : 53
push eax ;0x00457393 : 50
call Fun42c2be ;0x00457394 : e8254ffdff
mov edi , eax ;0x00457399 : 8bf8
add esp , 08h ;0x0045739b : 83c408
cmp edi , ebx ;0x0045739e : 3bfb
jne Label4573f1 ;0x004573a0 : 754f
cmp dword ptr [ ebp + 16 ] , ebx ;0x004573a2 : 395d10
mov esi , dword ptr [ ebp - 8 ] ;0x004573a5 : 8b75f8
jbe Label5eab6e ;0x004573a8 : 0f86c0371900
mov ecx , dword ptr [esi] ;0x004573ae : 8b0e
mov eax , dword ptr [ ebp + 12 ] ;0x004573b0 : 8b450c
mov dword ptr [ ecx + 24 ] , ebx ;0x004573b3 : 895918
mov edx , dword ptr [esi] ;0x004573b6 : 8b16
push esi ;0x004573b8 : 56
mov dword ptr [ edx + 32 ] , ebx ;0x004573b9 : 895a20
mov dword ptr [ Data9393ac ] , eax ;0x004573bc : a3ac939300
call Fun457433 ;0x004573c1 : e86d000000
;
; ----------------------------------------------------------------------------
; VFP 9.0 FIX - FIX THE POINTER OF P-CODE FOR THE ROWSOURCE PROPERTY
; February 2021
; ----------------------------------------------------------------------------
; CCB
;
; Fix the pointer of p-code for the RowSource property.
;
; 2021/2/21, by ccb
;
cmp dword ptr vfpa_sys9053_data,00h
je Label4573c6
cmp dword ptr [ esp + 078h ] , offset Label4cca83 ;; Fun4c70fc .. ; proc near
je Label4573c5
cmp dword ptr [ esp + 078h ] , offset Label5eaede ;; Fun4c70fc .. ; proc near
je Label4573c5
jmp Label4573c6
Label4573c5 ::
mov edx , dword ptr [ ebp - 16 ]
mov dword ptr [ Data9393ac ] , edx
Label4573c6 ::
mov ebx , dword ptr [ ebp + 8 ] ;0x004573c6 : 8b5d08
mov ecx , dword ptr [ ebx + 0140h ] ;0x004573c9 : 8b8b40010000
mov edx , 01h ;0x004573cf : ba01000000
call Fun42f404 ;0x004573d4 : e82b80fdff
mov ecx , dword ptr [eax] ;0x004573d9 : 8b08
mov dword ptr [ ecx + 0D0h ] , esi ;0x004573db : 89b1d0000000
mov edx , dword ptr [ ebx + 0140h ] ;0x004573e1 : 8b9340010000
pushd 00h ;0x004573e7 : 6a00
push edx ;0x004573e9 : 52
call Fun456e21 ;0x004573ea : e832faffff
xor ebx , ebx ;0x004573ef : 33db
Label4573f1 ::
mov ecx , dword ptr [ Data937220 ] ;0x004573f1 : 8b0d20729300
lea eax , dword ptr [ ebp - 100 ] ;0x004573f7 : 8d459c
cmp eax , ecx ;0x004573fa : 3bc1
jne Label5eab8e ;0x004573fc : 0f858c371900
mov ecx , dword ptr [ Data937220 ] ;0x00457402 : 8b0d20729300
mov eax , dword ptr [ ecx + 76 ] ;0x00457408 : 8b414c
cmp dword ptr [ ebp - 12 ] , eax ;0x0045740b : 3945f4
mov dword ptr [ Data937220 ] , eax ;0x0045740e : a320729300
jne Label5eab98 ;0x00457413 : 0f857f371900
cmp edi , ebx ;0x00457419 : 3bfb
mov edx , dword ptr [ ebp - 16 ] ;0x0045741b : 8b55f0
mov dword ptr [ Data9393ac ] , edx ;0x0045741e : 8915ac939300
jne Label5eaba2 ;0x00457424 : 0f8578371900
pop edi ;0x0045742a : 5f
pop esi ;0x0045742b : 5e
pop ebx ;0x0045742c : 5b
mov esp , ebp ;0x0045742d : 8be5
pop ebp ;0x0045742f : 5d
ret 0Ch ;0x00457430 : c20c00
4. APPLIES TO:
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
http://www.baiyujia.com/vfpdocuments/f_vfp9fix157.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix2.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix241.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix242.asp
2, foxite.com:
https://www.foxite.com/archives/combolist-box-causes-error-67-0000061756.htm
https://www.foxite.com/archives/error-67-expression-evaluator-failed-0000097598.htm
3, microsoft.com:
https://social.technet.microsoft.com/Forums/en-US/e6d46eca-dac8-4528-a697-69a69bf212e8/error-expression-evaluator-failed
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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