--------------------------------------------------------------
                      VFP 9.0 FIX - SYS(9079) CLEAN THE SYSTEM DATA BUFFER
                                February 2017
                 --------------------------------------------------------------
                                    CCB



1. THE SYS(9079) FUNCTION:

     SYS(9079) - Clean the system data buffer.

     Clean the system data buffer.

     SYS(9079 [, nSysdataID])	

     Parameters
     nSysdataID
     Specifies the Sysdata ID.

     Return Value
     Character

     Remarks
     Only for internal use in Visual FoxPro Advanced (x64).


2. CAUSE:

     There are some BUGs in the following code.


3. RESOLUTION:

     We can write some code to fix the BUG.

     Fun529fca :: ; proc near
             push ebp                                                        ;0x00529fca :        55
             mov ebp , esp                                                   ;0x00529fcb :        8bec
             pushd 0FFFFFFFFh                                                ;0x00529fcd :        6aff
             pushd offset Data922268                                                  ;0x00529fcf :        6868229200
             pushd offset Label9160f9                                                  ;0x00529fd4 :        68f9609100
             mov eax ,  dword ptr fs:[00h]                                   ;0x00529fd9 :        64a100000000
             push eax                                                        ;0x00529fdf :        50
             mov  dword ptr fs:[00h] , esp                                   ;0x00529fe0 :        64892500000000
             push ecx                                                        ;0x00529fe7 :        51
             push ecx                                                        ;0x00529fe8 :        51
             mov eax , 02FBCh                                                ;0x00529fe9 :        b8bc2f0000
             call Fun42c118                                                  ;0x00529fee :        e82521f0ff
             mov eax ,  dword ptr [ Data937090 ]                             ;0x00529ff3 :        a190709300
             mov  dword ptr [ ebp - 28 ] , eax                               ;0x00529ff8 :        8945e4
             push ebx                                                        ;0x00529ffb :        53
             push esi                                                        ;0x00529ffc :        56
             push edi                                                        ;0x00529ffd :        57
             mov  dword ptr [ ebp - 24 ] , esp                               ;0x00529ffe :        8965e8
             xor edi , edi                                                   ;0x0052a001 :        33ff
             mov  dword ptr [ ebp + 0FFFFD114h ] , edi                       ;0x0052a003 :        89bd14d1ffff
             push edi                                                        ;0x0052a009 :        57
             pushd 02710h                                                    ;0x0052a00a :        6810270000
             push edi                                                        ;0x0052a00f :        57
             mov  ebx , dword ptr [ ebp + 8 ]                                ;0x0052a010 :        8b5d08
             mov eax , ebx                                                   ;0x0052a013 :        8bc3
             call Fun529bc5                                                  ;0x0052a015 :        e8abfbffff
             mov  dword ptr [ ebp + 0FFFFD0E4h ] , eax                       ;0x0052a01a :        8985e4d0ffff
             mov  dword ptr [ ebp + 0FFFFD10Ch ] , edi                       ;0x0052a020 :        89bd0cd1ffff
             lea ecx ,  dword ptr [ ebp + 0FFFFFDE0h ]                       ;0x0052a026 :        8d8de0fdffff
             mov  dword ptr [ ebp + 0FFFFD100h ] , ecx                       ;0x0052a02c :        898d00d1ffff
             mov  byte ptr [ ebp + 0FFFFFDE0h ] , 00h                        ;0x0052a032 :        c685e0fdffff00
             movsx eax , ax                                                  ;0x0052a039 :        0fbfc0


     ;
     ;                 --------------------------------------------------------------
     ;                      VFP 9.0 FIX - SYS(9079) CLEAN THE SYSTEM DATA BUFFER
     ;                                February 2017
     ;                 --------------------------------------------------------------
     ;                                     CCB
     ;
     ; SYS(9079) - Clean the system data buffer.
     ;
     ; 2017/2/15, by ccb
     ;

             cmp eax,9079
             je vfpa_sys9079_start


             pushd 064h                                                      ;0x0052a03c :        6a64
             pop esi                                                         ;0x0052a03e :        5e
             cmp eax , esi                                                   ;0x0052a03f :        3bc6
             jle Label52a0d0                                                 ;0x0052a041 :        0f8e89000000
             mov ecx , 07EAh                                                 ;0x0052a047 :        b9ea070000
             cmp eax , ecx                                                   ;0x0052a04c :        3bc1
             jg Label52a164                                                  ;0x0052a04e :        0f8f10010000
             je Label609b33                                                  ;0x0052a054 :        0f84d9fa0d00
             mov ecx , 04F6h                                                 ;0x0052a05a :        b9f6040000
             cmp eax , ecx                                                   ;0x0052a05f :        3bc1
             jle Label52b6e0                                                 ;0x0052a061 :        0f8e79160000
             mov ecx , 07DBh                                                 ;0x0052a067 :        b9db070000
             cmp eax , ecx                                                   ;0x0052a06c :        3bc1
             jg Label51f355                                                  ;0x0052a06e :        0f8fe152ffff
             je Label609700                                                  ;0x0052a074 :        0f8486f60d00
             add ecx , 0FFFFFFF9h                                            ;0x0052a07a :        83c1f9
             cmp eax , ecx                                                   ;0x0052a07d :        3bc1
             jg Label4a4938                                                  ;0x0052a07f :        0f8fb3a8f7ff
             je Label4f6b07                                                  ;0x0052a085 :        0f847ccafcff
             sub eax , 04F7h                                                 ;0x0052a08b :        2df7040000
             je Label60951e                                                  ;0x0052a090 :        0f8488f40d00
             dec eax                                                         ;0x0052a096 :        48
             je Label60950f                                                  ;0x0052a097 :        0f8472f40d00
             sub eax , 0E4h                                                  ;0x0052a09d :        2de4000000
             je Label609492                                                  ;0x0052a0a2 :        0f84eaf30d00
             sub eax , 01F4h                                                 ;0x0052a0a8 :        2df4010000
             jne Label462026                                                 ;0x0052a0ad :        0f85737ff3ff
             lea eax ,  dword ptr [ ebp + 0FFFFFDE0h ]                       ;0x0052a0b3 :        8d85e0fdffff
             push eax                                                        ;0x0052a0b9 :        50
             push  dword ptr [ ebp + 12 ]                                    ;0x0052a0ba :        ff750c
             mov edx , ebx                                                   ;0x0052a0bd :        8bd3
             call Fun4dc923                                                  ;0x0052a0bf :        e85f28fbff


4. APPLIES TO:

     VFP 10.0.0.0 (VFP Advanced)


5. REFERENCE WEBSITES:

     1, baiyujia.com:
     http://www.baiyujia.com


6. OTHER:

     For reference only, there is no guarantees.

     Any questions or suggestions, please e-mail to ccb2000@163.com.