doc: remove GNU troff workaround

In 2007 the docbook project made the mistake of converting ' to \' for
man pages [1]. It's a problem because groff interprets \' as acute
accent which is rendered as ' in ASCII, but as ´ in utf-8.

This started a cascade of bug reports in git [2], debian [3], Arch Linux
[4], docbook itself [5], and probably many others.

A solution was to use the correct groff character: \(aq, which is always
rendered as ', but the problem is that such character doesn't work in
other troff programs.

A portable solution required the use of a conditional character that is
\(aq in groff, but ' in all others:

  .ie \n(.g .ds Aq \(aq
  .el .ds Aq '

The proper solution took time to be implemented in docbook, but in 2010
they did it [6]. So the docbook man page stylesheets were broken from
1.73 to 1.76.

Unfortunately by that point many workarounds already existed. In the
case of git, GNU_ROFF was introduced, and in the case of Arch Linux
a mapping from \' to ' was added to groff's man.local. Other
distributions might have done the same, or similar workarounds.

Since 2010 there is no need for this workaround, which is fixed
elsewhere, not just in docbook, but other layers as well.

Let's remove it.

[1] ea2a0bac56
[2] https://lore.kernel.org/git/20091012102926.GA3937@debian.b2j/
[3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=507673#65
[4] https://bugs.archlinux.org/task/9643
[5] https://sourceforge.net/p/docbook/bugs/1022/
[6] fb55343426

Inspired-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/Makefile

@@ -191,14 +191,6 @@ MAN_BASE_URL = file://$(htmldir)/
 endif
 XMLTO_EXTRA += -m manpage-base-url.xsl
 
-# 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
-
 ifdef USE_ASCIIDOCTOR
 ASCIIDOC = asciidoctor
 ASCIIDOC_CONF =

Documentation/manpage-quote-apos.xsl

@@ -1,16 +0,0 @@
-<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>

Makefile

@@ -207,10 +207,6 @@ include shared.mak
 # Define NO_ST_BLOCKS_IN_STRUCT_STAT if your platform does not have st_blocks
 # field that counts the on-disk footprint in 512-byte blocks.
 #
-# 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 USE_ASCIIDOCTOR to use Asciidoctor instead of AsciiDoc to build the
 # documentation.
 #