Maven: pom.xml tags beyond <configuration> are regarded as invalid (IDEA-89560)

plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenDomElementDescriptorProvider.java

@@ -15,12 +15,30 @@
  */
 package org.jetbrains.idea.maven.dom;
 
+import com.intellij.psi.PsiElement;
 import com.intellij.psi.impl.source.xml.XmlElementDescriptorProvider;
+import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.xml.XmlTag;
+import com.intellij.util.xml.DomElement;
+import com.intellij.util.xml.impl.DomManagerImpl;
 import com.intellij.xml.XmlElementDescriptor;
+import com.intellij.xml.impl.schema.AnyXmlElementDescriptor;
+import org.jetbrains.idea.maven.dom.model.MavenDomConfiguration;
 
 public class MavenDomElementDescriptorProvider implements XmlElementDescriptorProvider {
   public XmlElementDescriptor getDescriptor(XmlTag tag) {
+    DomElement domElement = DomManagerImpl.getDomManager(tag.getProject()).getDomElement(tag);
+    if (domElement == null) {
+      PsiElement configuration =
+        PsiTreeUtil.findFirstParent(tag, element -> element instanceof XmlTag && "configuration".equals(((XmlTag)element).getName()));
+      if (configuration instanceof XmlTag) {
+        DomElement configurationElement = DomManagerImpl.getDomManager(tag.getProject()).getDomElement((XmlTag)configuration);
+        if (configurationElement instanceof MavenDomConfiguration &&
+            configurationElement.getGenericInfo().getFixedChildrenDescriptions().isEmpty()) {
+          return new AnyXmlElementDescriptor(null, null);
+        }
+      }
+    }
     return MavenDomElementDescriptorHolder.getInstance(tag.getProject()).getDescriptor(tag);
   }
 }

plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenXmlExtension.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2000-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jetbrains.idea.maven.dom;
+
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.xml.XmlFile;
+import com.intellij.psi.xml.XmlTag;
+import com.intellij.util.xml.DomElement;
+import com.intellij.util.xml.DomUtil;
+import com.intellij.util.xml.impl.DomManagerImpl;
+import com.intellij.xml.DefaultXmlExtension;
+import com.intellij.xml.XmlElementDescriptor;
+import com.intellij.xml.impl.schema.AnyXmlElementDescriptor;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.idea.maven.dom.model.MavenDomConfiguration;
+
+/**
+ * @author Vladislav.Soroka
+ * @since 4/4/2017
+ */
+public class MavenXmlExtension extends DefaultXmlExtension {
+  @Override
+  public boolean isAvailable(PsiFile file) {
+    return file instanceof XmlFile && MavenDomUtil.isMavenFile(file);
+  }
+
+  @Nullable
+  @Override
+  public XmlElementDescriptor getElementDescriptor(XmlTag tag, XmlTag contextTag, XmlElementDescriptor parentDescriptor) {
+    DomElement domElement = DomManagerImpl.getDomManager(tag.getProject()).getDomElement(contextTag);
+    if (domElement != null) {
+      MavenDomConfiguration configuration = DomUtil.getParentOfType(domElement, MavenDomConfiguration.class, false);
+      if (configuration != null && configuration.getGenericInfo().getFixedChildrenDescriptions().isEmpty()) {
+        return new AnyXmlElementDescriptor(null, null);
+      }
+    }
+    return super.getElementDescriptor(tag, contextTag, parentDescriptor);
+  }
+}

plugins/maven/src/main/resources/META-INF/plugin.xml

@@ -116,7 +116,7 @@
     <localInspection language="XML" shortName="MavenPropertyInParent" bundle="MavenDomBundle" key="inspection.property.in.parent.name"
                      groupKey="inspection.group" enabledByDefault="true" level="WARNING"
                      implementationClass="org.jetbrains.idea.maven.dom.inspections.MavenPropertyInParentInspection"/>
-
+    <xml.xmlExtension implementation="org.jetbrains.idea.maven.dom.MavenXmlExtension"/>
     <dom.extender domClass="org.jetbrains.idea.maven.dom.model.MavenDomConfiguration"
                   extenderClass="org.jetbrains.idea.maven.dom.MavenPluginConfigurationDomExtender"/>
     <dom.extender domClass="org.jetbrains.idea.maven.dom.model.MavenDomConfigurationParameter"