[PATCH v2 1/5] doc: Allow rst2man.py as an alternative to rst2man

[W. Trevor King]

Gentoo's dev-python/docutils-0.10 installs Docutils scripts with a
*.py extension, so I have /usr/bin/rst2man.py and no rst2man script.
This patch supports users with both types of systems by checking for
rst2man, falling back on rst2man.py, and giving up only if neither is
found.  Users can also set the new RST2MAN path variable explicitly
when they call Make:

  make RST2MAN=/my/custom/rst_to_man_converter build-man

I use POSIX's 'command -v' [1] to find the path to rst2man or
rst2man.py, and save that as RST2MAN in Makefile.config.  Then pass
the configured RST2MAN path through to prerst2man.py to use in its
system call.

We can use a non-empty RST2MAN to check for the availability of an
rst2man program, so there's no need for a separate HAVE_RST2MAN.
However, we keep the existing HAVE_RST2MAN for consistency with
HAVE_SPHINX.

[1]: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html
---
 configure          | 15 +++++++++++++--
 doc/Makefile.local |  2 +-
 doc/prerst2man.py  |  9 +++++----
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/configure b/configure
index 9bde2eb..f017af8 100755
--- a/configure
+++ b/configure
@@ -413,17 +413,24 @@ if hash sphinx-build > /dev/null 2>&1 && python -m sphinx.writers.manpage > /dev
     printf "Yes.\n"
     have_sphinx=1
     have_rst2man=0
+    RST2MAN=
 else
     printf "No (falling back to rst2man).\n"
     have_sphinx=0
 
     printf "Checking if rst2man is available... "
     if rst2man -V > /dev/null 2>&1; then
-       printf "Yes.\n"
        have_rst2man=1
+       RST2MAN=$(command -v rst2man)
+       printf "Yes (${RST2MAN}).\n"
+    elif rst2man.py -V > /dev/null 2>&1; then
+       have_rst2man=1
+       RST2MAN=$(command -v rst2man.py)
+       printf "Yes (${RST2MAN}).\n"
     else
-       printf "No (so will not install man pages).\n"
        have_rst2man=0
+       RST2MAN=
+       printf "No (so will not install man pages).\n"
     fi
 fi
 
@@ -820,6 +827,10 @@ HAVE_SPHINX=${have_sphinx}
 # Whether there's a rst2man binary available for building documentation
 HAVE_RST2MAN=${have_rst2man}
 
+# The path to the rst2man program for building documentation.  Set to
+# an empty string if no such program is available.
+RST2MAN=${RST2MAN}
+
 # The directory to which desktop files should be installed
 desktop_dir = \$(prefix)/share/applications
 
diff --git a/doc/Makefile.local b/doc/Makefile.local
index bbd4610..d96cdd5 100644
--- a/doc/Makefile.local
+++ b/doc/Makefile.local
@@ -49,7 +49,7 @@ ifeq ($(HAVE_SPHINX),1)
 	    mv $(DOCBUILDDIR)/man/*.$${section} $(DOCBUILDDIR)/man/man$${section}; \
 	done
 else ifeq ($(HAVE_RST2MAN),1)
-	$(prerst2man) $(srcdir)/doc $(DOCBUILDDIR)/man
+	$(prerst2man) "$(RST2MAN)" $(srcdir)/doc $(DOCBUILDDIR)/man
 else
 	@echo "Fatal: build dependency fail."
 	@false
diff --git a/doc/prerst2man.py b/doc/prerst2man.py
index 437dea9..81ce817 100644
--- a/doc/prerst2man.py
+++ b/doc/prerst2man.py
@@ -4,8 +4,9 @@ from os.path import dirname, isdir
 from os import makedirs, system
 import re
 
-sourcedir = argv[1]
-outdir = argv[2]
+rst2man = argv[1]
+sourcedir = argv[2]
+outdir = argv[3]
 
 if not isdir(outdir):
     makedirs(outdir, 0o755)
@@ -59,5 +60,5 @@ for page in man_pages:
     outfile.write("".join(lines))
     outfile.close()
 
-    system('set -x; rst2man {0} {1}/{2}.{3}'
-           .format(filename, outdir, page[0], page[4]))
+    system('set -x; {0} {1} {2}/{3}.{4}'
+           .format(rst2man, filename, outdir, page[0], page[4]))
-- 
1.9.1.353.gc66d89d