Dear CA-Clipper 5.2 Developer, This file contains: A. The instructions for applying the CA-Clipper 5.2c patch to any North American version of CA-Clipper 5.2 including: 5.20, 5.2a or 5.2b. Please review these instructions carefully before attempting to apply the patch. B. The problem resolutions contained in the CA-Clipper 5.2c patch. C. A technical note pertaining to a problem within the RLOCK() and DBRLOCK() functions. ============================================================================== A. Instructions for patching 5.2 (any rev.) to 5.2c (rev. 204). REQUIRED FILES FOR PERFORMING UPDATE: 52CUS.EXE A self extracting .ZIP file that may be downloaded from the CLIPPER forum (library 0) on CompuServe. (GO CLIPPER). PATCH.EXE Updating engine required for use with all 52C *.RTPs. This file is also in Library 0 of the CLIPPER CompuServe forum. CONTENTS OF 52CUS.EXE: INSTALL.EXE Installation engine required for performing the CA-Clipper 5.2c installation patch. DISK.ID Installation identification file. INSTALL.DAT Installation script file. 52CDBU.LIF Compressed update file for CLIPPER5\SOURCE\DBU 52COBJ.LIF Compressed update file for CLIPPER5\OBJ 52CRL.LIF Compressed update file for CLIPPER5\SOURCE\RL 52CSAMPL.LIF Compressed update file for CLIPPER5\SOURCE\SAMPLE 52CSYS.LIF Compressed update file for CLIPPER5\SOURCE\SYS CLP52BIN.RTP Update file for CLIPPER5\BIN CLP52INC.RTP Update file for CLIPPER5\INCLUDE CLP52LIB.RTP Update file for CLIPPER5\LIB CLP52NG.RTP Update file for NG UPDATE PROCESS: 1. o Download the 52CUS.EXE file from Compuserve. 2. o Move to the disk drive and directory where the patch files are stored. EXAMPLE: C:\> CD\52CUS 3. o Insert a blank formated diskette in the A: drive and move to it. EXAMPLE: C:\52CUS> A: 4. o Execute the 52CUS.EXE file. EXAMPLE: A:\> C:52CUS 5. o Execute the installation program and follow it's simple instructions. EXAMPLE: A:\> INSTALL 6. o Move to your DBU directory, define RTLINK's behavior and re-compile DBU. EXAMPLE: A:\> C: C:\NG> CD \CLIPPER5\SOURCE\DBU C:\CLIPPER5\SOURCE\DBU> SET RTLINKCMD= C:\CLIPPER5\SOURCE\DBU> RMAKE DBU o Copy DBU.EXE to your BIN directory. EXAMPLE: C:\CLIPPER5\SOURCE\DBU> COPY DBU.EXE C:\CLIPPER5\BIN 7. o Move to your RL directory, re-compile RL. EXAMPLE: C:\CLIPPER5\SOURCE\DBU> CD \CLIPPER5\SOURCE\RL C:\CLIPPER5\SOURCE\RL> RMAKE RL o Copy RL.EXE to your BIN directory. EXAMPLE: C:\CLIPPER5\SOURCE\RL> COPY RL.EXE C:\CLIPPER5\BIN 8. o Move to your PLL directory, rebuild BASE52.PLL and BASE52.PLT. EXAMPLE: C:\CLIPPER5\SOURCE\RL> CD \CLIPPER5\PLL C:\CLIPPER5\PLL> RTLINK @BASE52 o Do not become alarmed if the message: "Undefined Symbols... should be resolved at EXE generation" appears during this step. 9. o The update process is now complete. The modified files will have a date stamp of 08/06/93 and a time stamp of 05:23pm. ============================================================================== B. Problems resolved by CA-Clipper 5.2c: 1. Fixed most instances of the DBFNTX/1210 error. 2. Fixed INDEXKEY() so that when it is called with an invalid order argument it will no longer corrupt the data at memory location 0000:0000 in dos and will no longer generate a General Protection Error in Exospace. 3. Fixed CMEM.OBJ (in Clipper.lib) so that the malloc(), _fmalloc(), free() and _ffree() memory allocation functions will return the correct information. 4. Fixed VM Integrity error when evaluating detached code blocks that are nested three or more deep. 5. Fixed VAL() so it no longer left justifys the result. 6. Fixed ACHOICE() so that it will not redraw the menu window after returning from the user specified function unless: A. the user specified function changes the number of elements in the menu array. B. the user specified function returned the new return code of AC_REDRAW (which can be found in ACHOICE.CH and has the numeric value of 4). 7. Fixed the Expanded Memory Manager so it will not attempt to use more than eight megabytes of EMM. Currently, Clipper can not take advantage of more than eight megabytes of EMM. Please note that the printed documentation is incorrect. This was the cause of many corruptions on systems that had more than eight megabytes of expanded memory. 8. Fixed an incorrect calculation in _xvalloc() that caused the Virtual Memory Manager to allocate 1K to much if the requested size + 16 (in bytes) was an even multiple of 1024. 9. Fixed an internal calculation that did not account for overflow when converting a segment:offset address to an absolute address. This could only be encountered by calling the VM API function:_xvalloc(). 10. Fixed several problems in the DBFCDX replaceable database driver. 11. Fixed a compatability problem between CA-Clipper Tools-II and CA-Clipper 5.2x. Developers using CA-Clipper Tools-II noticed unresolved symbols at link time. The CT2PATCH.OBJ file will resolve these problems and should be included as an object on the link line. Please note that CT2PATCH.OBJ is only intended for use with CA-Clipper Tools-II, those not using CA-Clipper Tools-II should not include this file in their applications. 12. Fixed DBU so that closing a file with an associated filter will no longer cause a DBCMD/2001 error. 13. Fixed DBU so that performing a replace will no longer cause a "Lock Required" error. 14. Fixed REPORT FORM so header will print when creating a report whose width is greater than 254 characters. 15. Fixed REPORT FORM so that it now ejects properly for groups. 16. Fixed REPORT FORM so that double spaced forms will now print properly. 17. Determined that the EG_SYNTAX error in REPORT FORM was not caused by an empty database. It was caused by the absence of a field name for the report. This is the correct behavior. 18. Fixed REPORT FORM so that it will respect the "SUMMARY ONLY" option when requested. 19. Fixed REPORT FORM so that it no longer prints an extra form feed after the report is completed. 20. Fixed RL so that it will save entered data from all entry screens instead of only the current display screen. 21. Fixed RL so that it will no longer save the rightmost column when it is empty. 22. Fixed RL so that it accepts "T" or "F" in it's question fields. It previously was limmited to "Y" or "N". ============================================================================== C: Technical Note: RLOCK()/DBRLOCK() problem o Problem: RLOCK() and DBRLOCK() (without any parameter) will not reliably lock a record under certain circumstances, even though their return values (.T.) indicate success. This occurs when locking a record in the child database of a relation, after the record pointer has been repositioned by a SEEK or GOTO, but before the data has been accessed. o Solution: A workaround for this problem is to use DBRLOCK( RECNO() ) instead of RLOCK() or DBRLOCK(). A simple way to implement this is: 1. Add the following statements to a copy of the std.ch header file: #translate RLOCK() => DBRLOCK( RECNO() ) #translate DBRLOCK() => DBRLOCK( RECNO() ) 2. Re-compile your program with the /u option, where is the modified STD.CH file. o EXAMPLE: use child shared new set index to childntx use parent shared new set relation to FieldOne into child goto 2 ---------------> if ( rlock() ) // change this rlock() to dbrlock(recno()) replace child->FieldTwo with parent->FieldTwo endif close data return o Note: This is a temporary workaround while a solution for the problem is being worked upon. ============================================================================== ==============================================================================