[PATCH v3] Quote ' as \(aq in manpages

[Thomas Rast <trast@student.ethz.ch>]

The docbook/xmlto toolchain insists on quoting ' as \'.  This does
achieve the quoting goal, but modern 'man' implementations turn the
apostrophe into a unicode "proper" apostrophe (given the right
circumstances), breaking code examples in many of our manpages.

Quote them as \(aq instead, which is an "apostrophe quote" as per the
groff_char manpage.

Unfortunately, as Anders Kaseorg kindly pointed out, this is not
portable beyond groff, so we add an extra Makefile variable GNU_ROFF
which you need to enable to get the new quoting.

Thanks also to Miklos Vajna for documentation.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
---

Anders Kaseorg wrote:
> On Wed, 21 Oct 2009, Junio C Hamano wrote:
> > > +# Define GNU_ROFF if you have GNU roff and you don't want to have pretty
> > > +# apostrophe so that cut&pasting examples to the shell will work.
> > 
> > This makes it sound as if groff is the only roff implementation that has 
> > this problem---iow, if we use non-GNU roff then the documentation comes 
> > out just fine.  Is that the case?
> 
> Yes:

I'll take your word for it, but I cannot test with anything non-GNU.

> In order to build a manpage that can be viewed correctly on both 
> platforms, the conditional logic should live in the manpage itself (as per 
> the bug comments I linked to and Thomas quoted from).

I reworded Miklos' doc patch a bit to indicate that it's about the
target system, and also added a slightly longer comment to the
Documentation/Makefile for completeness.


 Documentation/Makefile               |    8 ++++++++
 Documentation/manpage-quote-apos.xsl |   16 ++++++++++++++++
 Makefile                             |    4 ++++
 3 files changed, 28 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/manpage-quote-apos.xsl

diff --git a/Documentation/Makefile b/Documentation/Makefile
index 06b0c57..cd5b439 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -103,6 +103,14 @@ ifdef DOCBOOK_SUPPRESS_SP
 XMLTO_EXTRA += -m manpage-suppress-sp.xsl
 endif
 
+# If your target system uses GNU groff, it may try to render
+# apostrophes as a "pretty" apostrophe using unicode.  This breaks
+# cut&paste, so you should set GNU_ROFF to force them to be ASCII
+# apostrophes.  Unfortunately does not work with non-GNU roff.
+ifdef GNU_ROFF
+XMLTO_EXTRA += -m manpage-quote-apos.xsl
+endif
+
 SHELL_PATH ?= $(SHELL)
 # Shell quote;
 SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
diff --git a/Documentation/manpage-quote-apos.xsl b/Documentation/manpage-quote-apos.xsl
new file mode 100644
index 0000000..aeb8839
--- /dev/null
+++ b/Documentation/manpage-quote-apos.xsl
@@ -0,0 +1,16 @@
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<!-- work around newer groff/man setups using a prettier apostrophe
+     that unfortunately does not quote anything when cut&pasting
+     examples to the shell -->
+<xsl:template name="escape.apostrophe">
+  <xsl:param name="content"/>
+  <xsl:call-template name="string.subst">
+    <xsl:with-param name="string" select="$content"/>
+    <xsl:with-param name="target">'</xsl:with-param>
+    <xsl:with-param name="replacement">\(aq</xsl:with-param>
+  </xsl:call-template>
+</xsl:template>
+
+</xsl:stylesheet>
diff --git a/Makefile b/Makefile
index fea237b..2ccbe4a 100644
--- a/Makefile
+++ b/Makefile
@@ -159,6 +159,10 @@ all::
 # Define ASCIIDOC_NO_ROFF if your DocBook XSL escapes raw roff directives
 # (versions 1.72 and later and 1.68.1 and earlier).
 #
+# Define GNU_ROFF if your target system uses GNU groff.  This forces
+# apostrophes to be ASCII so that cut&pasting examples to the shell
+# will work.
+#
 # Define NO_PERL_MAKEMAKER if you cannot use Makefiles generated by perl's
 # MakeMaker (e.g. using ActiveState under Cygwin).
 #
-- 
1.6.5.1.144.g316236