Add new information about how to unpack the bison source on

MSDOS and other systems which have 8.3 file name restrictions
using djunpack.bat and fnchange.lst.

djgpp/README.in

@@ -51,13 +51,56 @@ This is a port of GNU Bison @VERSION@ to MSDOS/DJGPP.
 3.:     Building the binaries from sources.
         ===================================
 
-3.1.:   To build the binaries you will need the following binary packages:
+3.1.:   Create a temporary directory and copy the source package into the
+        directory.  If you download the source distribution from one of the
+        DJGPP sites, just unzip it preserving the directory structure
+        running *ONE* of the following commands:
+          unzip32 bsn@PACKAGE_VERSION@s.zip      or
+          djtarx bsn@PACKAGE_VERSION@s.zip       or
+          pkunzip -d bsn@PACKAGE_VERSION@s.zip
+        and proceed to the paragraph 3.3, below.
+
+3.2.:   Source distributions downloaded from one of the GNU FTP sites need
+        some more work to unpack, if LFN support is not available.  If LFN is
+        available then you can extract the source files from the archive with
+        any unzip program and proceed to the paragraph 3.3, below.  Any file
+        name issue will be handled by the the DJGPP configuration files.
+        To unpack the source distribution on SFN systems, first, you MUST use
+        the `djunpack' batch file to unzip the package.  That is because some
+        file names in the official distributions need to be changed to avoid
+        problems on the various platforms supported by DJGPP.
+        `djunpack' invokes the `djtar' program (that is part of the basic DJGPP
+        development kit) to rename these files on the fly given a file with
+        name mappings; the distribution includes a file `djgpp/fnchange.lst'
+        with the necessary mappings.  So you need first to retrieve that batch
+        file, and then invoke it to unpack the distribution.  Here's how:
+
+          djtar -x -p -o bison-2.1/djgpp/djunpack.bat bison-2.1.tar.gz > djunpack.bat
+          djunpack bison-2.1.tar.gz
+
+        (The name of the distribution archive and the leading directory of the
+        path to `djunpack.bat' in the distribution will be different for
+        versions of Bison other than 2.1.)
+
+        If the argument to `djunpack.bat' include leading directories, it MUST
+        be given with the DOS-style backslashes; Unix-style forward slashes
+        will NOT work.
+
+        If the distribution comes as a .tar.bz2 archive, and your version of
+        `djtar' doesn't support bzip2 decompression, you need to unpack it as
+        follows:
+
+          bnzip2 bison-2.1.tar.bz2
+          djtar -x -p -o bison-2.1/djgpp/djunpack.bat bison-2.1.tar > djunpack.bat
+          djunpack bison-2.1.tar
+
+3.3.:   To build the binaries you will need the following binary packages:
           djdev203.zip (or a later but NOT a prior version)
           bsh204b.zip  (or a later but NOT a prior version)
           gcc400b.zip, gpp400b.zip, bnu215b.zip, mak3791b.zip,
           fil40b.zip, shl20jb.zip, txt20b.zip,
           txi48b.zip, grep24b.zip, sed414b.zip,
-          m4-143b.zip.
+          m4-144b.zip.
 
         If you want to run the check you will need also:
           dif281b.zip
@@ -66,20 +109,12 @@ This is a port of GNU Bison @VERSION@ to MSDOS/DJGPP.
         ftp.delorie.com mirror.
         You will need bsh203b.zip or later and *NOT* a prior version or
         the build will fail.  The same applies to djdev203.zip.  Please note
-        that Bison requires m4-143b.zip or later to work properly. All the
+        that Bison requires m4-144b.zip or later to work properly.  All the
         other packages are the ones I have used to build the binaries
         from this source.  Previuos versions of this packages may do the
         job as well but I have not tested this.
 
-3.2.:   Create a temporary directory and copy the source package into the
+3.4.:   If for some reason you want to reconfigure the package cd into the top
-        directory. If you download the source distribution from one of the
-        DJGPP archives, just unzip it preserving the directory structure
-        running *ONE* of the following commands:
-          unzip32 bsn@PACKAGE_VERSION@s.zip      or
-          djtarx bsn@PACKAGE_VERSION@s.zip       or
-          pkunzip -d bsn@PACKAGE_VERSION@s.zip
-
-3.3.:   If for some reason you want to reconfigure the package cd into the top
         srcdir (bison-@TREE_VERSION@) and run the following commands:
           del djgpp\config.cache
           make clean
@@ -109,11 +144,10 @@ This is a port of GNU Bison @VERSION@ to MSDOS/DJGPP.
         modifications to the Makefile.in's and supply all other needed options
         to the configure script.
 
-
+3.5.:   To compile the package run from the top srcdir the command:
-3.4.:   To compile the package run from the top srcdir the command:
           make
 
-3.5.:   Now you can run the tests if you like. From the top srcdir run the
+3.6.:   Now you can run the tests if you like.  From the top srcdir run the
         command:
           make check
 
@@ -121,7 +155,7 @@ This is a port of GNU Bison @VERSION@ to MSDOS/DJGPP.
         Please note that the testsuite only works with LFN available.  On plain
         DOS, most of the tests will fail due to invalid DOS names.
 
-3.6.:   To install the binaries, header, library, catalogs, and info docs
+3.7.:   To install the binaries, header, library, catalogs, and info docs
         run the following command from the top srcdir:
           make install