Version 6.8.0, 2019-11-15

  Allow for negative curvatures.

Version 6.5.4, 2014-07-19

  Fix configure.ac and edit.c to allow use of libedit.

Version 6.5.3, 2014-04-22

  To satisfy Coverity: more secure tmpfile creation, 
  check two return values

Version 6.5.2, 2013-10-11

   Correct a bug in undoing a mini or text edit.
   Replaced trailing pointers by pointers-to-pointers.

Version 6.5.1, 2012-05-24

   Use editline if available; readline otherwise.
   (editline emulation of readline is broken)

Version 6.5.0, 2012-05-13

   Revert to readline (available in gnuwin32 repository).
   Remove references to chmod and /dev/null.

Version 6.4.2, 2012-04-18

  Revert to editline using native libedit.so.

Version 6.4.1, 2012-04-17

  Revert to readline (libedit doesn't build on Cygwin).

Version 6.4.0, 2012-04-12

  Switch from (system) readline to (embedded) editline (libedit).

Version 6.3.2, 2012-03-28

  Support coordinate ranges for delete, shift, raise commands.
  Multiple-step commands undone atomically.

Version 6.3.1, 2012-03-26

  Support xchange command.
  Display new coordinates of shifted/raised nodes for subsequent raise/shift.

Version 6.3, 2012-03-21

  Support opt course boxes.

Version 6.2.1, 2012-03-18

  Allow multiple coordinate pairs in cut command.

Version 6.2, 2011-09-08

  Replace undelete command by a general multi-level undo command.
  Default for undoing paste command is to re-insert at the original coordinates.

Version 6.1.1, 2011-08-20

  Fixed missing else which resulted in re-reading ...coursec commands.
  Better prompt for background color of a course box.
  Better error message if more than one node at a point.

Version 6.1.0, 2011-08-18

  Deal with commands \halfcoursec etc. that allow background-color 
  specification.

Version 6.0.4, 2011-07-27

  Deleted prerex_LDFLAGS from src/Makefile.am.

Version 6.0.3, 2010-07-04

  Use only one of ncurses/termcap.

Version 6.0.2, 2010-06-29

  Deleted reference to stdbool.h.
  Modified configuration scripts to allow for readline using ncurses/termcap.

Version 6.0.1, 2010-06-28

  Modified configuration scripts to allow building on OpenSUSE (and Ubuntu?)

Version 6.0, 2010-06-25

  Allow long options --help and --version.
  Using autoconf/automake.

Version 5.8, 2010-04-10

  Suppress ".tex" in the prompt.

Version 5.7, 2010-04-05

  Delete command can now delete more than one element/arrow.
  Turning off all pdflatex output.

Version 5.6.1, 2010-03-26

  Open tex_file for writing before restoring from backup.

Version 5.6, 2010-03-25

  Modified chmod system calls to be compatible with cygwin on Windows fat32.
  Closing the tex_file before processing it (needed for Windows).
  Simplified the log-output generation if processing fails.
  Always use pdflatex because of automatic rotation in ps2pdf.

Version 5.5, 2010-03-16

  Added sleep(1) between initial generations of the pdf file.
  Removed all interactions before initial generation of pdf file.
  Removed the option of opening another tex file.
  Removed the automatic start-up of PDFVIEWER.
  Added PRIVATE (i.e., static) specifiers where appropriate.

Version 5.4, 2009-11-12

  Must re-open tex_file to regenerate it (!)

Version 5.3, 2009-10-30

  Use ps2pdf without attempting rotation correction when using latex,
    but, to allow for a script that tests for "Orientation: Landscape" in the ps file,
    if the environment variable PS2PDF is defined, its value is used in lieu of ps2pdf.

  Offer to quit if the user won't provide a file name.

  Allow for PAGER == most.

  Code clean-up, especially localizing many globals.

Version 5.2, 2009-10-19

  Corrected coding for new file name in open_tex_file.

Version 5.1, 2009-10-01

  Final processing no longer automatically uses LaTeX.

Version 5.0, 2009-09-15

  Replaced filename by basefilename and chartfilename to allow more than
  one document to share an included chart file and allow more than one
  chart to be included in a document.  The *file* command has been removed.

Version 4.3, 2009-09-06

  Replaced strlcpy and strlcpy by append (with offset).
  Introduced triv_type to avoid a "pedantic" error.
  Corrected an incorrect sizeof argument in open_tex_file.
  Call regenerate_and_process after a partial raise.

Version 4.2, 2008-07-17

  Use the /Orientation directive to gs (ghostscript) to ensure proper orientation
  when slanted fonts are used.

Version 4.1, 2008-05-16

  Implement shift/raise of specified diagram elements.
  Eliminate unnecessary dependence on libtermcap.

Version 4.0.1, 2008-02-28

  Corrected txt field of struct text to have size LINE_LEN+1

Version 4.0, 2008-02-13

  Test for curvatures > 100.
  Implement \text command.

Version 3.8.1, 2007-03-17

  Sleep for KILL_WAIT seconds before terminating the pdf viewer.

Version I.8, 2007-02-08

  Semicolon appended to most user commands suppresses regeneration and reprocessing.
  ^C saves to file.tex. Use quit; to exit without saving.
  Final processing uses latex -> dvips -> ps2pdf to produce a smaller final pdf.
  Attempts to display the pdf during editing using value of environment variable 
    PDFVIEWER. 

Version 3.7, 2006-12-27

  latex->dvips->ps2pdf processing restored as an option.
  Warns about quitting with unpasted cuts.

Version 3.6, 2006-11-29

  Corrects two minor logical errors in code for arrow deletion and box editing. 
  Generates progress messages when analyzing/saving/processing.
  Re-loads after every shell escape, so we can discard the Edit command.
  Applies shift/raise to cut and deleted nodes.
  Processes tex files using pdflatex instead of latex -> dvips -> ps2pdf.

Version 3.5, 2006-11-20
  
  simpler and more flexible implementation of cut/paste, delete/undelete
  generate undelete messages
  automatic re-generation and processing after editing operation

Version 3.4, 2006-11-15

  deal with files that are (initially) read-only
  deal with attempts to cut arrows

Version 3.3, 2006-11-07

  preserve comment lines within the chart environment
  correct option-handling bug introduced in 3.0

Version 3.2, 2006-11-03
Version 3.1, 2006-10-29

  introduce Edit command
  restore write-access to TeX file during Edit or shell-command execution
  try to display error message in log file if LaTeX processing fails

Version 3.0, 2006-10-19

  replaced calls to make file.pdf by successive calls to latex, dvips, ps2pdf
  removed all references to pdf viewer, user must start one him/herself
  replaced strncpy/cat by strlcpy/cat (my implementation of the OpenBSD functions)
  produce warning message for truncated course code, timetable, title

Version 2.4, 2006-04-12

  added undelete command
  no warnings using -Wall -Wextra
  allow for cut/paste of minis that are targets of arrow
  test for non-existence of source/target box/mini for new arrow
  handle more signals than SIGINT (such as SIGSEGV)

Version 2.3, 2006-03-23

  remove "which" checking of pdfviewer to allow, e.g., xpdf -remote label
  use geometry.sty for new blank TeX file
  declarations of optarg, optind moved to prerex.h

Version 2.2.2, 2006-03-08

  Free linked structures and readline strings.
  Turn grid off initially before restoring a backup.

Version 2.2.1, 2006-02-18

  Don't try to remove/restore access to an empty filename.

Version 2.2, 2006-02-15

  Inputs and outputs \begin{chart} ... \end{chart} instead of \chart{ ... }

Version 2.1.1, 2006-02-13

  Add designation PRIVATE ( = static) to definitions of functions and variables.

Version 2.1, 2006-02-09

  Trap SIGINT in order to restore write-access after ^C.
  Add Backup command.

Version 2.0.3, 2006-02-07

  New arrow should have default curvature.

Version 2.0.1, 2006-02-06

 Free list structures before Restoring.

Version 2.0, 2006-02-03

  Partition into separate modules prerex.c, inout.c, edit.c

Version 1.2.2, 2006-02-02

  Cleanup curvature code.
  Use %s to output % in regenerate_tex_file.

Version 1.2.1, 2006-02-02

  Allow for curved recommended and co-requisite arrows.

Version 1.2.0, 2006-02-01

  Restore command.

Version 1.1.2, 2006-01-31

  Create backup of Tex file before editing.
  Re-open TeX file for writing before regenerating.

Version 1.1.1, 2006-01-30

  TeX file read-only during editing (except when re-generating it).

Version 1.1.0, 2006-01-29

  Corrected use of cut stacks.
  Eliminated cut arrow command.
  Introduced delete box/mini and delete arrow.
  Checked for duplicate boxes, minis or arrows (e.g., when pasting).

Version 1.0.5, 2006-01-28

  Keep stacks of cut boxes, minis, and arrows.

Version 1.0.4, 2006-01-27

  Add option -p.

Version 1.0.3, 2006-01-26

  Replace system calls to "xpdf" by calls to pdfviewer (if defined).

Version 1.0.2, 2006-01-25

  Replace system call to "pdflatex filename" by call to "make filename.pdf"
    to provide more flexibility (e.g., LaTeX vs pdfLaTeX).

Version 1.0.1, 2006-01-24
  Error message for pdflatex failure now refers to filename.log.
  Inserted checks for lp or cp increasing too far in read_textfield 
    and read_bracketed_textfield.
  Process TeX file before analyzing it (as a syntax sanity pre-check).
  Defer arrow output if source box not previously output.
