Distribution dates other than those shown correspond to changes (usually of
documentation) not involving functionality.

2018 02 01 Enabled the use of snprintf for some (at least) 64-bit compilers.
 Tweaked the source for warning-free -pedantic compilation. Renamed dpicdoc.pdf
 to dpic-doc.pdf. Cleaned up the C code to assume c99/POSIX 2008 compiling.
2017 12 01 Improved configure script. Fixed a bug to retain the name of
 a linear object followed by continue. 
2017 08 01 The value last box.rad gives a value instead of an error.  The
 unscaled environment variables are unaffected when scale is changed.
2017 06 01 The tikz node for a named string is given the dpic string name.
2017 01 01 Changed "last line.wid" to return arrowhead wid; similarly for
 .ht and for other linear objects.
 (2017 04 22): Recent distributions of this version contain changes to the
 source, p2c/src and Pgen/src directories for gcc 5.4 and for 64-bit
 compilation; normal installation is unaffected.
2016 08 24 Fixed a bug involving labels within if statements.
2016 07 12 Minor cleanup of code and distribution files.
2016 07 04 Gcc flags include -ansi by default. Treat \# in strings as
 ordinary characters. Removed zero characters from error msgs.  Fixed a bug
 with macro arguments in strings. Cleanup of string code.
2015 12 31 Code tweaked to remove memory leaks.  Pascal source included in the
           distribution.
2015 11 05 Added robustness for different compilers, easier p2c conversion.
2015 08 31 Ljust and rjust text offset equal for single and multiple strings.
2015 08 13 Catch return value of the sh command.
2015 06 29 Fixed a bug in svg output.
2015 06 15 Undeferred error messaging. Improved readability of C code.
2015 04 01 Fix comment lines containing braces in macro and for bodies. Revised
           messages for some errors.
2015 02 13 Reworked the handling of backslashes in strings in macro arguments.
2015 02 04 PDF output. Built-in variable dpicopt and variables added for
           detecting command options.  Linear objects reworked for consistent
           fill.
2014 01 26 Tweak svg string output.
2014 01 01 Input lines of arbitrary length and line continuation (except in
           strings).  Object parameters .thick = .thickness and .len = .length,
           eg t=last box.thick; q = last line.len
2013 09 30 Better portability of the random() function
2013 03 09 Minor tweak to svg output
2013 02 27 dpic returns EXIT_FAILURE on fatal errors or (errcount > 0);
           warnings are not counted.
2012 11 04 Change to always send errors to /dev/stderr
2012 07 07 Fixed the previous fix to handle planar objects correctly
2012 06 20 Give line attributes the effect behaviour for pgf and pstricks ouput
2012 04 19 Error message for zero second argument to pmod(,)
2012 02 07 Fixed a mishandling of null macro arguments in loops.
2011 12 09 Fix to handle reference to invalid predefined variables gracefully.
2011 10 25 Bugfixes: exec "string"
2011 05 31 Basic hash and faster search for variables, at the expense of
           increased storage for [ ] blocks. Adjusted svg size parameters.
2011 03 17 Compile #elif for OpenBSD
2011 01 24 Cleanup of dpic -t output.
2010 12 29 Reworked for loops to allow assignment to the loop variable.
2010 12 07 Fixed a bug in psfrag output.
2010 11 28 Bug fix for (string > string)
2010 11 21 Bug fix in expressions of the form string + sprintf(...)
2010 10 31 Optional arrowhead parameter after -> or <- or <->
2010 09 21 Default arrowhead parameter set to 1 to conform to gpic.
2010 07 13 Better justification of stacked text.
2010 06 16 Type 3 arrowheads
2010 05 11 Fix treatment of < character.
2010 05 02 SVG tweaks.
2010 03 15 Curved arc arrowheads for -f, -f, -m, -p, -s and updated -m output.
2010 03 05 Curved arc arrowheads in Postscript and SVG output.
2010 02 19 Fixed an obscure bug with macro args.
2010 02 17 SVG output units changed to px and pt
2010 02 11 -v option to produce SVG output
2010 01 11 Generalized sprintf("string",args) to sprintf(stringexpr,args)
2009 10 30 Tweaked Makefiles for easier Linux installation. Give an error
           message on attempt to set scale parameter to 0.
2009 10 21 Skip white space preceding pic macro arguments;
           e.g. macro( a, <newline> b ) is equivalent to macro(a,b )
2009 07 13 Skip newline after ":" to conform with gpic (see 2008 10 29).
2009 07 09 Added line "shade" for Postscript output, to fill arbitrary polygons.
2009 06 12 Consistent arrowhead on multisegment linear objects.
2009 06 03 More obscure grammar tweaks.
2009 05 29 Slightly streamlined grammar; bugfix for nested x<A,B> constructs.
2009 05 19 Allow "shade" attribute for linear objects with output in PSTricks,
           MPost, and PGF format.  Bugfix for arrowhead.
2009 04 04 Slight change to error message for unknown character.
2009 01 16 Bugfix for continued lines ending in CR LF (PC text) in macros.
2009 01 07 Require filename to contain at least one visible character.
2009 01 04 Redirection added to the print command to allow
           print arg > "filename" or print arg >> "filename" (except safe mode).
2008 10 29 arrowhead = 0 implemented.
2008 10 29 Previously the line A: <newline> was permitted, and was equivalent to
           A: Here but this has been disallowed to conform to other processors.
2008 10 29 More detailed syntax error messages.

For several years prior to mid-2008, there were few changes to dpic except
for the occasional bug fix.  Feel free to report any bugs in the latest
version.