[PATCH] doc: Allow rst2man.py as an alternative to rst2man

[David Bremner]

From: "W. Trevor King" <wking at tremily.us>

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

We 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.
---

At the risk of bike-shedding, rewrite the configure check to be more
"obvious". This is pretty subjective, but in particular I'm not a big
fan of resetting RST2MAN at the bottom of every iteration of the for
loop.  Also conform a bit more to the convention of using a lower case variable in configure and assigning it in Makefile.

For some reason it bugs me a bit to pass RST2MAN as an extra command line argument, but I guess taking some arguments by command line and some by environment variables would also be icky.

configure          | 23 ++++++++++++++++-------
 doc/Makefile.local |  2 +-
 doc/prerst2man.py  |  9 +++++----
 3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/configure b/configure
index 137acea..fdf5bad 100755
--- a/configure
+++ b/configure
@@ -444,21 +444,27 @@ else
 fi
 
 printf "Checking if sphinx is available and supports nroff output... "
+have_sphinx=0
+have_rst2man=0
+
 if hash sphinx-build > /dev/null 2>&1 && ${python} -m sphinx.writers.manpage > /dev/null 2>&1 ; then
     printf "Yes.\n"
     have_sphinx=1
-    have_rst2man=0
 else
     printf "No (falling back to rst2man).\n"
-    have_sphinx=0
 
+    rst2man=
     printf "Checking if rst2man is available... "
-    if rst2man -V > /dev/null 2>&1; then
-       printf "Yes.\n"
-       have_rst2man=1
-    else
+    for name in rst2man rst2man.py; do
+	if "${name}" -V > /dev/null 2>&1; then
+	    printf "Yes (${name}).\n"
+	    have_rst2man=1
+	    rst2man=$name
+	    break
+	fi
+    done
+    if [ $have_rst2man -eq 0 ]; then
        printf "No (so will not install man pages).\n"
-       have_rst2man=0
     fi
 fi
 
@@ -854,6 +860,9 @@ HAVE_RST2MAN=${have_rst2man}
 # Whether there's a doxygen binary available for building api documentation
 HAVE_DOXYGEN=${have_doxygen}
 
+# The path to the rst2man program for building documentation.
+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 e7d0bac..a13cb37 100644
--- a/doc/Makefile.local
+++ b/doc/Makefile.local
@@ -51,7 +51,7 @@ 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 968722a..2e87976 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)
@@ -60,5 +61,5 @@ 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]))
-- 
2.1.3