From e568824ea21f983841b8ab9e2afbcf0c57573f0b Mon Sep 17 00:00:00 2001
From: Nick Bowler <nbowler@draconx.ca>
Date: Tue, 8 Jan 2019 23:27:39 -0500
Subject: [PATCH] Strip leading and trailing whitespace from all <p> tags.

This should be harmless and improves the pretty-printed output a lot.
---
 layouts/default.xsl   |  8 ++++++++
 layouts/functions.xsl | 47 +++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/layouts/default.xsl b/layouts/default.xsl
index d7381d5..020d1fd 100644
--- a/layouts/default.xsl
+++ b/layouts/default.xsl
@@ -100,6 +100,14 @@
   </xsl:choose>
 </xsl:template>
 
+<!-- Clean up whitespace where harmless to do so -->
+<xsl:template match='xhtml:p/node()[1][self::text()]'>
+  <xsl:value-of select='f:strip-leading()' />
+</xsl:template>
+<xsl:template match='xhtml:p/node()[position()=last()][self::text()]'>
+  <xsl:value-of select='f:strip-trailing()' />
+</xsl:template>
+
 <!-- Add rel attributes to external links -->
 <xsl:template match='xhtml:a[starts-with(@href,"http://")
                           or starts-with(@href,"https://")
diff --git a/layouts/functions.xsl b/layouts/functions.xsl
index cdfb482..96952b2 100644
--- a/layouts/functions.xsl
+++ b/layouts/functions.xsl
@@ -63,8 +63,51 @@
 <!-- Returns true iff the node is a nonempty text node or a span element -->
 <func:function name='f:node-is-span'>
   <xsl:param name='node' select='.' />
-  <func:result test='( $node/self::text() and normalize-text($node) )
-                     or f:element-is-span($node)' />
+  <func:result select='( $node/self::text() and normalize-text($node) )
+                       or f:element-is-span($node)' />
+</func:function>
+
+<!-- Remove leading whitespace from a string -->
+<func:function name='f:strip-leading'>
+  <xsl:param name='str' select='.' />
+  <xsl:param name='curlen' select='string-length($str)' />
+
+  <xsl:variable name='a' select='substring($str, 1, $curlen)' />
+  <xsl:variable name='b' select='substring($str, 1+$curlen)' />
+
+  <xsl:choose>
+    <xsl:when test='2 > $curlen'>
+      <func:result select='concat(normalize-space($a), $b)' />
+    </xsl:when>
+    <xsl:when test='normalize-space($a) = ""'>
+      <func:result select='f:strip-leading($b)' />
+    </xsl:when>
+    <xsl:otherwise>
+      <func:result select='f:strip-leading($str, ceiling($curlen div 2))' />
+    </xsl:otherwise>
+  </xsl:choose>
+</func:function>
+
+<!-- Remove trailing whitespace from a string -->
+<func:function name='f:strip-trailing'>
+  <xsl:param name='str' select='.' />
+  <xsl:param name='curlen' select='string-length($str)' />
+
+  <xsl:variable name='split' select='string-length($str) - $curlen' />
+  <xsl:variable name='a' select='substring($str, 1, $split)' />
+  <xsl:variable name='b' select='substring($str, 1+$split)' />
+
+  <xsl:choose>
+    <xsl:when test='2 > $curlen'>
+      <func:result select='concat($a, normalize-space($b))' />
+    </xsl:when>
+    <xsl:when test='normalize-space($b) = ""'>
+      <func:result select='f:strip-trailing($a)' />
+    </xsl:when>
+    <xsl:otherwise>
+      <func:result select='f:strip-trailing($str, ceiling($curlen div 2))' />
+    </xsl:otherwise>
+  </xsl:choose>
 </func:function>
 
 </xsl:stylesheet>
-- 
2.43.0