Skip multi-release source sets in idea project import by default (elastic#107123)

There is an existing IntelliJ bug that prevents doing a full project
build when source sets for multi-release jars are present. This changes
the project import behavior so that these source sets are ignored by
default and can be explicitly enabled by adding
`org.gradle.mrjar.idea.enabled=true` to your
`~/.gradle/gradle.properties` file should you need to actively work on
that code.

Author: mark-vieira

build-tools-internal/src/main/groovy/elasticsearch.ide.gradle

@@ -130,7 +130,8 @@ if (providers.systemProperty('idea.active').getOrNull() == 'true') {
       ':server:generateModulesList',
       ':server:generatePluginsList',
       ':generateProviderImpls',
-      ':libs:elasticsearch-native:elasticsearch-native-libraries:extractLibs'].collect { elasticsearchProject.right()?.task(it) ?: it })
+      ':libs:elasticsearch-native:elasticsearch-native-libraries:extractLibs',
+      ':x-pack:libs:es-opensaml-security-api:shadowJar'].collect { elasticsearchProject.right()?.task(it) ?: it })
   }
 
   // this path is produced by the extractLibs task above
@@ -239,20 +240,22 @@ if (providers.systemProperty('idea.active').getOrNull() == 'true') {
  * but before the XML document, e.g. a doctype or comment
  */
 void modifyXml(Object path, Action<? super Node> action, String preface = null) {
-  Node xml = parseXml(path)
-  action.execute(xml)
+  if (project.file(path).exists()) {
+    Node xml = parseXml(path)
+    action.execute(xml)
 
-  File xmlFile = project.file(path)
-  xmlFile.withPrintWriter { writer ->
-    def printer = new XmlNodePrinter(writer)
-    printer.namespaceAware = true
-    printer.preserveWhitespace = true
-    writer.write("<?xml version=\"1.0\"?>\n")
+    File xmlFile = project.file(path)
+    xmlFile.withPrintWriter { writer ->
+      def printer = new XmlNodePrinter(writer)
+      printer.namespaceAware = true
+      printer.preserveWhitespace = true
+      writer.write("<?xml version=\"1.0\"?>\n")
 
-    if (preface != null) {
-      writer.write(preface)
+      if (preface != null) {
+        writer.write(preface)
+      }
+      printer.print(xml)
     }
-    printer.print(xml)
   }
 }
 

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/MrjarPlugin.java

@@ -49,6 +49,7 @@
 public class MrjarPlugin implements Plugin<Project> {
 
     private static final Pattern MRJAR_SOURCESET_PATTERN = Pattern.compile("main(\\d{2})");
+    private static final String MRJAR_IDEA_ENABLED = "org.gradle.mrjar.idea.enabled";
 
     private final JavaToolchainService javaToolchains;
 
@@ -61,23 +62,30 @@ public class MrjarPlugin implements Plugin<Project> {
     public void apply(Project project) {
         project.getPluginManager().apply(ElasticsearchJavaBasePlugin.class);
         var javaExtension = project.getExtensions().getByType(JavaPluginExtension.class);
-
-        List<Integer> mainVersions = findSourceVersions(project);
-        List<String> mainSourceSets = new ArrayList<>();
-        mainSourceSets.add(SourceSet.MAIN_SOURCE_SET_NAME);
-        List<String> testSourceSets = new ArrayList<>(mainSourceSets);
-        testSourceSets.add(SourceSet.TEST_SOURCE_SET_NAME);
-        for (int javaVersion : mainVersions) {
-            String mainSourceSetName = SourceSet.MAIN_SOURCE_SET_NAME + javaVersion;
-            SourceSet mainSourceSet = addSourceSet(project, javaExtension, mainSourceSetName, mainSourceSets, javaVersion);
-            configureSourceSetInJar(project, mainSourceSet, javaVersion);
-            mainSourceSets.add(mainSourceSetName);
-            testSourceSets.add(mainSourceSetName);
-
-            String testSourceSetName = SourceSet.TEST_SOURCE_SET_NAME + javaVersion;
-            SourceSet testSourceSet = addSourceSet(project, javaExtension, testSourceSetName, testSourceSets, javaVersion);
-            testSourceSets.add(testSourceSetName);
-            createTestTask(project, testSourceSet, javaVersion, mainSourceSets);
+        var isIdea = System.getProperty("idea.active", "false").equals("true");
+        var ideaSourceSetsEnabled = project.hasProperty(MRJAR_IDEA_ENABLED) && project.property(MRJAR_IDEA_ENABLED).equals("true");
+
+        // Ignore version-specific source sets if we are importing into IntelliJ and have not explicitly enabled this.
+        // Avoids an IntelliJ bug:
+        // https://youtrack.jetbrains.com/issue/IDEA-285640/Compiler-Options-Settings-language-level-is-set-incorrectly-with-JDK-19ea
+        if (isIdea == false || ideaSourceSetsEnabled) {
+            List<Integer> mainVersions = findSourceVersions(project);
+            List<String> mainSourceSets = new ArrayList<>();
+            mainSourceSets.add(SourceSet.MAIN_SOURCE_SET_NAME);
+            List<String> testSourceSets = new ArrayList<>(mainSourceSets);
+            testSourceSets.add(SourceSet.TEST_SOURCE_SET_NAME);
+            for (int javaVersion : mainVersions) {
+                String mainSourceSetName = SourceSet.MAIN_SOURCE_SET_NAME + javaVersion;
+                SourceSet mainSourceSet = addSourceSet(project, javaExtension, mainSourceSetName, mainSourceSets, javaVersion);
+                configureSourceSetInJar(project, mainSourceSet, javaVersion);
+                mainSourceSets.add(mainSourceSetName);
+                testSourceSets.add(mainSourceSetName);
+
+                String testSourceSetName = SourceSet.TEST_SOURCE_SET_NAME + javaVersion;
+                SourceSet testSourceSet = addSourceSet(project, javaExtension, testSourceSetName, testSourceSets, javaVersion);
+                testSourceSets.add(testSourceSetName);
+                createTestTask(project, testSourceSet, javaVersion, mainSourceSets);
+            }
         }
 
         configureMrjar(project);