[bugfix] Fix DOM compliance of in-memory DOM so that Element#getAttribute(String) and Element#getAttributeNS(String, String) return an empty string (and not null) if the attribute does not exist

Closes eXist-db/exist#5672

Author: adamretter

exist-core/pom.xml

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * 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; version 2.1.
+ *
+ * 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
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -21,7 +45,6 @@
  */
 package org.exist.backup.restore;
 
-import org.apache.commons.lang3.StringUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.exist.Namespaces;
@@ -44,6 +67,8 @@
 import java.io.IOException;
 import java.util.*;
 
+import static org.exist.util.StringUtil.isNullOrEmpty;
+
 /**
  * Utility to compare the applications contained in a backup with the already
  * installed applications in the package repo.
@@ -141,7 +166,7 @@ public void startElement(String uri, String localName, String qName, Attributes
                             if (PKG_NAMESPACE.equals(uri) && "package".equals(localName)) {
                                 final String version = attributes.getValue("version");
                                 final String name = attributes.getValue("name");
-                                if (StringUtils.isEmpty(version) || StringUtils.isEmpty(name)) {
+                                if (isNullOrEmpty(version) || isNullOrEmpty(name)) {
                                     LOG.warn("Invalid package descriptor for {}", app.getSymbolicPath());
                                     return;
                                 }

exist-core/src/main/java/org/exist/backup/restore/AppRestoreUtils.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * 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; version 2.1.
+ *
+ * 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
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -160,7 +184,7 @@ protected void read(final DBBroker broker, final Document doc, final boolean che
                 } else if (VALIDATION_ELEMENT.equals(node.getLocalName())) {
                     final Element elem = (Element) node;
                     final String mode = elem.getAttribute(VALIDATION_MODE_ATTR);
-                    if (mode == null) {
+                    if (mode.isEmpty()) {
                         LOG.debug("Unable to determine validation mode in {}", srcCollectionURI);
                         validationMode = XMLReaderObjectFactory.VALIDATION_SETTING.UNKNOWN;
                     } else {

exist-core/src/main/java/org/exist/collections/CollectionConfiguration.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * 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; version 2.1.
+ *
+ * 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
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -23,7 +47,6 @@
 
 import java.util.*;
 
-import org.apache.commons.lang3.StringUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.exist.collections.Collection;
@@ -45,6 +68,9 @@
 import org.exist.xquery.XQueryContext;
 import org.exist.xquery.value.Sequence;
 
+import static org.exist.util.StringUtil.endsWith;
+import static org.exist.util.StringUtil.substringBeforeLast;
+
 /**
  * Startup Trigger to fire XQuery scripts during database startup.
  *
@@ -124,7 +150,7 @@ private List<String> getScriptsInStartupCollection(DBBroker broker) {
 
                         if (isPermissionsOK(document)) {
 
-                            if (StringUtils.endsWithAny(docPath, XQUERY_EXTENSIONS)) {
+                            if (endsWith(docPath, XQUERY_EXTENSIONS)) {
                                 paths.add(XmldbURI.EMBEDDED_SERVER_URI_PREFIX + docPath);
 
                             } else {
@@ -255,7 +281,7 @@ private void executeQuery(DBBroker broker, String path) {
                 context = new XQueryContext(broker.getBrokerPool());
 
                 // Allow use of modules with relative paths
-                String moduleLoadPath = StringUtils.substringBeforeLast(path, "/");
+                String moduleLoadPath = substringBeforeLast(path, "/");
                 context.setModuleLoadPath(moduleLoadPath);
 
                 // Compile query

exist-core/src/main/java/org/exist/collections/triggers/XQueryStartupTrigger.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * 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; version 2.1.
+ *
+ * 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
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -342,7 +366,7 @@ public Long getPropertyLong(final String name, final Long defaultValue, final bo
 
     public Integer getPropertyMegabytes(String name, Integer defaultValue) {
         String cacheMem = element.getAttribute(name);
-        if (cacheMem != null) {
+        if (!cacheMem.isEmpty()) {
             if (cacheMem.endsWith("M") || cacheMem.endsWith("m")) {
                 cacheMem = cacheMem.substring(0, cacheMem.length() - 1);
             }