Documentation: use "spurious .sp" XSLT if DOCBOOK_SUPPRESS_SP is set

With this change, the "spurious .sp" suppression XSLT code is
disabled by default. It can be enabled by defining
DOCBOOK_SUPPRESS_SP.

The "spurious .sp" XSLT fragment was used to work around a bug
first released in docbook-xsl 1.69.1. Modern versions of
docbook-xsl are negatively affected by the code (some empty lines
are omitted from manpage output; see
<http://article.gmane.org/gmane.comp.version-control.git/115302>).

The key revisions in the docbook SVN repo seem to be 5144 (before
docbook-xsl 1.69.1) and 6359 (before docbook-xsl 1.71.1).

Testing done with asciidoc 8.3.1 and docbook-xsl 1.74.0.

Signed-off-by: Chris Johnsen <chris_johnsen@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 32 insertions, 14 deletions

diff --git a/Documentation/Makefile b/Documentation/Makefile
index dae317466..dba97dc21 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -69,7 +69,9 @@ endif
 #
 # For docbook-xsl ...
 #	-1.68.1,	set ASCIIDOC_NO_ROFF? (based on changelog from 1.73.0)
-#	1.69.0-1.71.1,	no extra settings are needed?
+#	1.69.0,		no extra settings are needed?
+#	1.69.1-1.71.0,	set DOCBOOK_SUPPRESS_SP?
+#	1.71.1,		no extra settings are needed?
 #	1.72.0,		set DOCBOOK_XSL_172.
 #	1.73.0-,	set ASCIIDOC_NO_ROFF
 #
@@ -97,6 +99,9 @@ endif
 ifdef MAN_BOLD_LITERAL
 XMLTO_EXTRA += -m manpage-bold-literal.xsl
 endif
+ifdef DOCBOOK_SUPPRESS_SP
+XMLTO_EXTRA += -m manpage-suppress-sp.xsl
+endif
 
 #
 # Please note that there is a minor bug in asciidoc.
diff --git a/Documentation/RelNotes-1.6.3.txt b/Documentation/RelNotes-1.6.3.txt
index 0d8260a84..95405907b 100644
--- a/Documentation/RelNotes-1.6.3.txt
+++ b/Documentation/RelNotes-1.6.3.txt
@@ -102,6 +102,11 @@ Updates since v1.6.2
 * Makefile learned 'coverage' option to run the test suites with
   coverage tracking enabled.
 
+* Building the manpages with docbook-xsl between 1.69.1 and 1.71.1 now
+  requires setting DOCBOOK_SUPPRESS_SP to work around a docbook-xsl bug.
+  This workaround used to be enabled by default, but causes problems
+  with newer versions of docbook-xsl.
+
 Fixes since v1.6.2
 ------------------
 
diff --git a/Documentation/manpage-base.xsl b/Documentation/manpage-base.xsl
index 16e2e4097..a264fa616 100644
--- a/Documentation/manpage-base.xsl
+++ b/Documentation/manpage-base.xsl
@@ -32,17 +32,4 @@
 	<xsl:text>br&#10;</xsl:text>
 </xsl:template>
 
-<!-- attempt to work around spurious .sp at the tail of the line
-     that docbook stylesheets seem to add -->
-<xsl:template match="simpara">
-  <xsl:variable name="content">
-    <xsl:apply-templates/>
-  </xsl:variable>
-  <xsl:value-of select="normalize-space($content)"/>
-  <xsl:if test="not(ancestor::authorblurb) and
-                not(ancestor::personblurb)">
-    <xsl:text>&#10;&#10;</xsl:text>
-  </xsl:if>
-</xsl:template>
-
 </xsl:stylesheet>
diff --git a/Documentation/manpage-suppress-sp.xsl b/Documentation/manpage-suppress-sp.xsl
new file mode 100644
index 000000000..a63c7632a
--- /dev/null
+++ b/Documentation/manpage-suppress-sp.xsl
@@ -0,0 +1,21 @@
+<!-- manpage-suppress-sp.xsl:
+     special settings for manpages rendered from asciidoc+docbook
+     handles erroneous, inline .sp in manpage output of some
+     versions of docbook-xsl -->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<!-- attempt to work around spurious .sp at the tail of the line
+     that some versions of docbook stylesheets seem to add -->
+<xsl:template match="simpara">
+  <xsl:variable name="content">
+    <xsl:apply-templates/>
+  </xsl:variable>
+  <xsl:value-of select="normalize-space($content)"/>
+  <xsl:if test="not(ancestor::authorblurb) and
+                not(ancestor::personblurb)">
+    <xsl:text>&#10;&#10;</xsl:text>
+  </xsl:if>
+</xsl:template>
+
+</xsl:stylesheet>