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[BUG/PRB.] VFP 9.0 FIX - COMBOBOX CONTROL ENTER AN INFINITE LOOP
January 2024
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CCB
1. BUG:
For the ComboBox Control, sometimes (called some API Library functions?) VFP will enter an infinite loop.
2. CAUSE:
There are some BUGs in the following code.
3. RESOLUTION:
We can write some code to fix the BUG.
Label4eaf09 ::
push esi ;0x004eaf09 : 56
mov esi , dword ptr [ Data9370f0 ] ;0x004eaf0a : 8b35f0709300
add esi , 02Ch ;0x004eaf10 : 83c62c
call Fun53cefe ;0x004eaf13 : e8e61f0500
;
; ---------------------------------------------------------------
; VFP 9.0 FIX - COMBOBOX CONTROL ENTER AN INFINITE LOOP
; March 2016
; ---------------------------------------------------------------
; CCB
;
; For the ComboBox Control, sometimes (called some API Library functions?) VFP will enter an infinite loop.
;
; VFP initializes the Value.ev_type to "I" (Integer),
; but VFP does not initialize the Value.ev_long,
; so the Value.ev_long is a random number, sometimes (called some API Library functions?) it is a BIG random number,
; so VFP will enter an infinite loop.
;
; We can initialize the Value.ev_long to 0 (Zero) to fix the BUG.
;
; 2016/3/29, by ccb
;
mov dword ptr [ esi + 12 ] , 00h
lea edx , dword ptr [ esp + 16 ] ;0x004eaf18 : 8d542410
push edx ;0x004eaf1c : 52
pushd 00h ;0x004eaf1d : 6a00
pushd 039h ;0x004eaf1f : 6a39
push edi ;0x004eaf21 : 57
call Fun4ea4ba ;0x004eaf22 : e893f5ffff
mov dword ptr [ebx] , eax ;0x004eaf27 : 8903
mov eax , dword ptr [ esp + 16 ] ;0x004eaf29 : 8b442410
test eax , eax ;0x004eaf2d : 85c0
pop esi ;0x004eaf2f : 5e
jne Label5f3d47 ;0x004eaf30 : 0f85118e1000
jmp Label4e3b57 ;0x004eaf36 : e91c8cffff
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
http://www.baiyujia.com/vfpdocuments/f_vfp9fix365.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix366.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix367.asp
http://www.baiyujia.com/vfpdocuments/f_vfp9fix368.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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