[xslt] func:function and "xsltApplySequenceConstructor: value-of was not compiled"

[Phil Shafer <phil juniper net>]

Should exsltFuncFunctionComp() be compiling it's contents?  Currently
it calls xsltParseTemplateContent(), but not xsltInitElemPreComp()
(or similar function).

The impact is that if you make the mistake of putting content
directly in your <func:function>, you get:

xsltApplySequenceConstructor: value-of was not compiled

and no clue where the bug in your script is.   If your script also
has text nodes, you get:

xsltApplySequenceConstructor: value-of was not compiled
  ELEMENT fake
element fake: error : Node has no parent
    TEXT
      content=        
{http://xml.juniper.net/test}test-func: cannot write to result tree while executing a function
xmlXPathCompiledEval: evaluation failed
runtime error: file /tmp/te30.xsl line 5 element value-of
XPath evaluation returned no result.

which is much more helpful.  Would compiling the contents of the
function help get a better error to the user?

Examples appended (with and without text nodes).

Thanks,
 Phil

---------------

% cat /tmp/te30.xsl
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; xmlns:func="http://exslt.org/functions"; xmlns:test-ns="http://xml.juniper.net/test"; version="1.0">
  <xsl:template match="/">
    <test>
      <xsl:value-of select="test-ns:test-func()"/>
    </test>
  </xsl:template>
  <func:function name="test-ns:test-func">
    <xsl:value-of select="concat(&quot;Between &quot;, $x)"/>
  </func:function>
</xsl:stylesheet>
% xsltproc /tmp/te30.xsl /tmp/te30.xsl
xsltApplySequenceConstructor: value-of was not compiled
  ELEMENT fake
element fake: error : Node has no parent
    TEXT
      content=        
{http://xml.juniper.net/test}test-func: cannot write to result tree while executing a function
xmlXPathCompiledEval: evaluation failed
runtime error: file /tmp/te30.xsl line 5 element value-of
XPath evaluation returned no result.
<?xml version="1.0"?>
<test xmlns:func="http://exslt.org/functions"; xmlns:test-ns="http://xml.juniper.net/test"/>
% cat /tmp/te30a.xsl
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; xmlns:func="http://exslt.org/functions"; xmlns:test-ns="http://xml.juniper.net/test"; version="1.0">
  <xsl:template match="/">
    <test>
      <xsl:value-of select="test-ns:test-func()"/>
    </test>
  </xsl:template>
  <func:function name="test-ns:test-func"><xsl:value-of select="concat(&quot;Between &quot;, $x)"/></func:function>
</xsl:stylesheet>
% xsltproc /tmp/te30a.xsl /tmp/te30a.xsl
xsltApplySequenceConstructor: value-of was not compiled
<?xml version="1.0"?>
<test xmlns:func="http://exslt.org/functions"; xmlns:test-ns="http://xml.juniper.net/test"/>
% diff -u /tmp/te30.xsl /tmp/te30a.xsl
--- /tmp/te30.xsl	2012-03-26 14:27:46.000000000 -0400
+++ /tmp/te30a.xsl	2012-03-26 16:02:51.000000000 -0400
@@ -5,7 +5,5 @@
       <xsl:value-of select="test-ns:test-func()"/>
     </test>
   </xsl:template>
-  <func:function name="test-ns:test-func">
-    <xsl:value-of select="concat(&quot;Between &quot;, $x)"/>
-  </func:function>
+  <func:function name="test-ns:test-func"><xsl:value-of select="concat(&quot;Between &quot;, $x)"/></func:function>
 </xsl:stylesheet>
% xsltproc --version
Using libxml 20708, libxslt 10126 and libexslt 815
xsltproc was compiled against libxml 20707, libxslt 10126 and libexslt 815
libxslt 10126 was compiled against libxml 20707
libexslt 815 was compiled against libxml 20707
%