Merge pull request #3508 from adamretter/hotfix/string-length-inside-…

…predicate

Fix an issue with the context item as an argument to fn:string-length inside a predicate

exist-core/src/main/java/org/exist/xquery/AnalyzeContextInfo.java

@@ -114,18 +114,29 @@ public int getFlags() {
      * 
      * @param flags processing flags to be passed to child expression
      */
-    public void setFlags(int flags) {
+    public void setFlags(final int flags) {
         this.flags = flags;
     }
 
-    public void addFlag(int flag) {
+    public void addFlag(final int flag) {
         flags |= flag;
     }
 
-    public void removeFlag(int flag) {
+    public void removeFlag(final int flag) {
         flags &= ~flag;
     }
 
+    /**
+     * Determines if a flag is set.
+     *
+     * @param flag the flag to test for
+     *
+     * @return true if the flag is set, false otherwise.
+     */
+    public boolean hasFlag(final int flag) {
+        return (flags & flag) == flag;
+    }
+
     /**
      * Returns the parent of the current expression.
      *

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

@@ -69,7 +69,8 @@ public FunStrLength(final XQueryContext context, final FunctionSignature signatu
     protected Tuple2<Expression, Integer> strictCheckArgumentType(Expression argument,
             @Nullable final SequenceType argType, final AnalyzeContextInfo argContextInfo, final int argPosition,
             int returnType) {
-        if (getArgumentCount() == 1 && (argContextInfo.getFlags() & LocationStep.DOT_TEST) == LocationStep.DOT_TEST) {
+        if (getArgumentCount() == 1 && argContextInfo.hasFlag(LocationStep.DOT_TEST)
+                && !argContextInfo.hasFlag(Expression.IN_PREDICATE)) {
             /*
                 fn:string-length has different behaviour with regards the context item...
                 See https://www.biglist.com/lists/lists.mulberrytech.com/xsl-list/archives/201906/msg00021.html

exist-core/src/test/java/org/exist/xquery/functions/fn/FunStrLengthTest.java

@@ -0,0 +1,69 @@
+/*
+ * eXist-db Open Source Native XML Database
+ * Copyright (C) 2001 The eXist-db Authors
+ *
+ * info@exist-db.org
+ * 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
+ */
+package org.exist.xquery.functions.fn;
+
+import org.exist.test.ExistXmldbEmbeddedServer;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.xmldb.api.base.ResourceSet;
+import org.xmldb.api.base.XMLDBException;
+import org.xmldb.api.modules.XPathQueryService;
+
+import static org.junit.Assert.assertEquals;
+
+public class FunStrLengthTest {
+
+    @ClassRule
+    public static final ExistXmldbEmbeddedServer server = new ExistXmldbEmbeddedServer(true, true, true);
+
+    @Test
+    public void contextItemWithinPredicate() throws XMLDBException {
+        final XPathQueryService queryService = (XPathQueryService) server.getRoot().getService("XQueryService", "1.0");
+
+        ResourceSet results = null;
+
+        // upon empty sequence
+        results = queryService.query("()[fn:string-length(.) gt 0]");
+        assertEquals(0, results.getSize());
+
+        // upon computed empty sequence
+        results = queryService.query("fn:tokenize('', '/')[fn:string-length(.) gt 0]");
+        assertEquals(0, results.getSize());
+
+        // upon non-empty sequence
+        results = queryService.query("('a', '', 'bc', '', 'def')[fn:string-length(.) gt 0]");
+        assertEquals(3, results.getSize());
+        assertEquals("a", results.getResource(0).getContent());
+        assertEquals("bc", results.getResource(1).getContent());
+        assertEquals("def", results.getResource(2).getContent());
+
+        // upon computed non-empty sequence
+        results = queryService.query("fn:tokenize('ab/c//def//g//', '/')[fn:string-length(.) gt 0]");
+        assertEquals(4, results.getSize());
+        assertEquals("ab", results.getResource(0).getContent());
+        assertEquals("c", results.getResource(1).getContent());
+        assertEquals("def", results.getResource(2).getContent());
+        assertEquals("g", results.getResource(3).getContent());
+    }
+
+
+}