fn:transform - convert XPath error from Saxon call

Initial attempt at returning a correct error code per fn:transform specification and consistent with error codes returned by the Saxon transformer which is used internally.

Figure out if an an XPathException from Saxon (a saxon class) or an eXist XPathException was a cause of an exception in Saxon invocation.

Return a directly wrapped eXist XPathException as the cause of a new eXist XPathException.
Return a wrapped Saxon XPathException as the cause of a new eXist XPathException.

Generate/convert/wrap into an appropriate eXist XPathException.

Author: alanpaxton

exist-core/src/main/java/org/exist/xquery/functions/fn/FnTransform.java

@@ -31,6 +31,7 @@
 import net.sf.saxon.Configuration;
 import net.sf.saxon.expr.parser.RetainedStaticContext;
 import net.sf.saxon.functions.SystemProperty;
+import net.sf.saxon.om.StructuredQName;
 import net.sf.saxon.s9api.*;
 import net.sf.saxon.serialize.SerializationProperties;
 import net.sf.saxon.trans.UncheckedXPathException;
@@ -177,23 +178,53 @@ private XsltExecutable compileExecutable(final Options options) throws XPathExce
             FnTransform.ERROR_LISTENER.clear();
             return xsltCompiler.compile(options.xsltSource._2); // .compilePackage //TODO(AR) need to implement support for xslt-packages
         } catch (final SaxonApiException e) {
-            Throwable cause = e.getCause();
-            while (cause != null) {
-                if (cause instanceof XPathException) {
-                    //Generated by us, possibly in URI resolution, above - throw it directly
-                    throw (XPathException) cause;
-                }
-                cause = cause.getCause();
-            }
+            //Generated by us, possibly in URI resolution, above - throw it directly
+            throwOriginalXPathException(e, ErrorCodes.FOXT0003);
             final Optional<TransformerException> compilerException = FnTransform.ERROR_LISTENER.getWorst();
             if (compilerException.isPresent()) {
-                throw new XPathException(this, ErrorCodes.FOXT0003,compilerException.get());
+                throwOriginalXPathException(compilerException.get(), ErrorCodes.FOXT0003);
+                throw new XPathException(this, ErrorCodes.FOXT0003, compilerException.get());
             }
             //Wrap any other error
             throw new XPathException(this, ErrorCodes.FOXT0003, e.getMessage());
         }
     }
 
+    /**
+     * Search for an XPathException in the cause chain, and return it "directly"
+     * Either an eXist XPathException, which is immediate
+     * Or a Saxon XPathException, when we convert it to something similar in eXist.
+     *
+     * @param e the top of the exception stack
+     * @param defaultErrorCode use this code and its description to fill in blanks in what we finally throw
+     * @throws XPathException the eventual eXist exception we may throw
+     */
+    private void throwOriginalXPathException(final Throwable e, final ErrorCodes.ErrorCode defaultErrorCode) throws XPathException {
+        Throwable cause = e;
+        while (cause != null) {
+            if (cause instanceof XPathException) {
+                throw (XPathException) cause;
+            }
+            cause = cause.getCause();
+        }
+
+        cause = e;
+        while (cause != null) {
+            if (cause instanceof net.sf.saxon.trans.XPathException) {
+                final net.sf.saxon.trans.XPathException xPathException = (net.sf.saxon.trans.XPathException)cause;
+                final StructuredQName from = xPathException.getErrorCodeQName();
+                if (from != null) {
+                    final QName errorCodeQName = new QName(from.getLocalPart(), from.getURI(), from.getPrefix());
+                    final ErrorCodes.ErrorCode errorCode = new ErrorCodes.ErrorCode(errorCodeQName, defaultErrorCode.getDescription());
+                    throw new XPathException(errorCode, cause.getMessage());
+                } else {
+                    throw new XPathException(this, defaultErrorCode, cause.getMessage());
+                }
+            }
+            cause = cause.getCause();
+        }
+    }
+
     /**
      * Hash on the options used to create a compiled executable
      * Hash should match only when the executable can be re-used.

exist-core/src/test/java/xquery/xquery3/XQuery3Tests.java

@@ -27,7 +27,7 @@
 @RunWith(XSuite.class)
 @XSuite.XSuiteFiles({
         //"src/test/xquery/xquery3",
-        "src/test/xquery/xquery3/fnTransform74.xqm"
+        "src/test/xquery/xquery3/fnTransformErr9.xqm"
 })
 public class XQuery3Tests {
 }

exist-core/src/test/xquery/xquery3/fnTransform71.xqm

@@ -0,0 +1,58 @@
+(:
+ : eXist-db Open Source Native XML Database
+ : Copyright (C) 2001 The eXist-db Authors
+ :
+ : [email protected]
+ : http://www.exist-db.org
+ :
+ : This library is free software; you can redistribute it and/or
+ : modify it under the terms of the GNU Lesser General Public
+ : License as published by the Free Software Foundation; either
+ : version 2.1 of the License, or (at your option) any later version.
+ :
+ : This library is distributed in the hope that it will be useful,
+ : but WITHOUT ANY WARRANTY; without even the implied warranty of
+ : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ : Lesser General Public License for more details.
+ :
+ : You should have received a copy of the GNU Lesser General Public
+ : License along with this library; if not, write to the Free Software
+ : Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ :)
+xquery version "3.1";
+
+module namespace testTransform="http://exist-db.org/xquery/test/function_transform";
+
+declare namespace test="http://exist-db.org/xquery/xqsuite";
+
+declare variable $testTransform:transform-71-xsl := document {
+<xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform'
+            xmlns:xs='http://www.w3.org/2001/XMLSchema'
+            xmlns:chrono='http://chronology.com/' version='2.0'>
+            <xsl:import-schema>
+              <xs:schema targetNamespace='http://chronology.com/'>
+                <xs:simpleType name='c4'>
+                  <xs:restriction base='xs:string'>
+                    <xs:pattern value='....'/>
+                  </xs:restriction>
+                </xs:simpleType>
+              </xs:schema>
+            </xsl:import-schema>
+            <xsl:template name='main'>
+              <out><xsl:value-of select="chrono:c4('abcd')"/></out>
+            </xsl:template>
+        </xsl:stylesheet> };
+
+declare
+    %test:assertError("XTSE1650")
+function testTransform:transform-71() {
+    let $xsl := $testTransform:transform-71-xsl
+    let $result := fn:transform(map{
+    "stylesheet-node":$xsl,
+                "source-node": parse-xml($xsl),
+                "initial-template": fn:QName('','main'),
+                    "delivery-format" : "serialized",
+                    "requested-properties" : map{fn:QName('http://www.w3.org/1999/XSL/Transform','is-schema-aware'):false()}
+                    })
+    return $result("output")
+};