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<file> option, where
        <file> 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.



==============================================================================
==============================================================================
