Use str:replace from exslt.org to implement string.subst

string.subst implementation causes recursion issues when building
systemd documentation. This issue has been reported in
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=765567 and
https://bugs.archlinux.org/task/54694 .

A possible fix consists in using str:replace from exslt.org when this
function is available. This has been implemented in a patch for the
Debian package
(https://anonscm.debian.org/cgit/collab-maint/docbook-xsl.git/tree/debian/patches/765567_non-recursive_string_subst.patch)
which has also been used by Arch Linux
(https://git.archlinux.org/svntogit/packages.git/tree/trunk/765567_non-recursive_string_subst.patch?h=packages/docbook-xsl&id=c6bf4ebc446487043437ed13e4fbe83f648f5c58).

Translate this patch to xsl/lib/lib.xweb in order to fix the recursion
issues.

For reference, here is the beginning of the error messages reported by
xslt when building systemd:

      XSLT     man/systemd.directives.html
    Note: namesp. add : added namespace before processing              systemd.directives
    runtime error: file file:/usr/share/xml/docbook/xsl-stylesheets-1.79.2/lib/lib.xsl line 56 element variable
    xsltApplySequenceConstructor: A potential infinite template recursion was detected.
    You can adjust xsltMaxDepth (--maxdepth) in order to raise the maximum number of nested template calls and variables/params (currently set to 3000).
    Templates:
    #0 name string.subst
    #1 name string.subst
    #2 name string.subst
    #3 name string.subst
    #4 name string.subst
    #5 name string.subst
    #6 name string.subst
    #7 name string.subst
    #8 name string.subst
    #9 name string.subst
    #10 name string.subst
    #11 name string.subst
    #12 name string.subst
    #13 name string.subst
    #14 name string.subst
    Variables:
    #0
    replacement   Object is a Node Set :
    Set contains 1 nodes:
      1    ATTRIBUTE newstring
          TEXT
            content= .

    target   Object is a Node Set :
    Set contains 1 nodes:
      1    ATTRIBUTE oldstring
          TEXT
            content=  .

    string   Object is a string : PP \fB\-\-multiple\fR .RS 4 \fBsystemd-a...

    #1
    target   Object is a Node Set :
    Set contains 1 nodes:
      1    ATTRIBUTE oldstring
          TEXT
            content=  .

    string   Object is a string : PP \fB\-\-multiple\fR .RS 4 \fBsystemd-a...

    #2
    string   Object is a string : PP \fB\-\-multiple\fR .RS 4 \fBsystemd-a...

    #3
    replacement   Object is a Node Set :
    Set contains 1 nodes:
      1    ATTRIBUTE newstring
          TEXT
            content= .

    target   Object is a Node Set :
    Set contains 1 nodes:
      1    ATTRIBUTE oldstring
          TEXT
            content=  .

    string   Object is a string : PP \fB\-\-mode=\fR .RS 4 \fBsystemd-inhi...

    #4
    target   Object is a Node Set :
    Set contains 1 nodes:
      1    ATTRIBUTE oldstring
          TEXT
            content=  .

    string   Object is a string : PP \fB\-\-mode=\fR .RS 4 \fBsystemd-inhi...

diff --git a/xsl/lib/lib.xweb b/xsl/lib/lib.xweb
index ec7372eda867483f672ca22a59c8f664ca4fcca2..e1b1905ed259e51f00f2a81c26be4bc28c5ed730 100644 (file)
--- a/xsl/lib/lib.xweb
+++ b/xsl/lib/lib.xweb
@@ -6,7 +6,8 @@
   xmlns:xlink="http://www.w3.org/1999/xlink"
   xmlns:dyn="http://exslt.org/dynamic"
   xmlns:ssb="http://sideshowbarker.net/ns"
-  xmlns:saxon="http://icl.com/saxon">
+  xmlns:saxon="http://icl.com/saxon"
+  xmlns:str="http://exslt.org/strings">
   <info>
     <title>XSL Library Template Reference</title>
     <releaseinfo role="cvs"></releaseinfo>
@@ -142,6 +143,9 @@ with <parameter>replacement</parameter> and returns the result.
   <xsl:param name="replacement"></xsl:param>
 
   <xsl:choose>
+    <xsl:when xmlns:str="http://exslt.org/strings" str:foo="" test="function-available('str:replace')">
+      <xsl:value-of select="str:replace($string, string($target), string($replacement))"/>
+    </xsl:when>
     <xsl:when test="contains($string, $target)">
       <xsl:variable name="rest">
         <xsl:call-template name="string.subst">