findClass should correctly sort compiled classes located inside project content (IDEA-101806)

java/java-tests/testSrc/com/intellij/psi/resolve/ResolveInLibrariesTest.groovy

@@ -160,7 +160,7 @@ class ResolveInLibrariesTest extends JavaCodeInsightFixtureTestCase {
 
   @Override
   protected boolean toAddSourceRoot() {
-    return false;
+    return name != "test do not build stubs in source jars";
   }
 
   public void "test do not build stubs in source jars"() {
@@ -197,4 +197,24 @@ class ResolveInLibrariesTest extends JavaCodeInsightFixtureTestCase {
     assert !StubTreeLoader.instance.canHaveStub(vfile)
     assert file.stub // from text
   }
+
+  public void "test directory with class files inside project content"() {
+    def testData = PathManagerEx.getTestDataPath() + "/codeInsight/interJarDependencies"
+    myFixture.setTestDataPath(testData)
+    PsiTestUtil.addLibrary(myModule, "lib2", testData, "lib2.jar");
+
+    myFixture.copyDirectoryToProject("lib1", "lib1")
+    PsiTestUtil.addLibrary(myModule, "lib1", myFixture.tempDirFixture.getFile("").path, "lib1");
+
+    myFixture.configureFromExistingVirtualFile(myFixture.addFileToProject("TestCase.java", """
+class Testcase {
+    public static void main( String[] args ) {
+        new B().<error descr="Cannot resolve method 'a()'">a</error>(); // should not work, because the A in lib1 has no method a
+        new B().a2(); // should work, because the A with this method is in lib1
+    }
+}
+""").virtualFile)
+    myFixture.checkHighlighting()
+  }
+
 }

platform/indexing-impl/src/com/intellij/openapi/module/impl/scopes/ModuleWithDependenciesScope.java

@@ -176,10 +176,8 @@ public class ModuleWithDependenciesScope extends GlobalSearchScope {
 
   @Nullable
   private VirtualFile getFileRoot(@NotNull VirtualFile file) {
-    if (myProjectFileIndex.isInContent(file)) {
-      return myProjectFileIndex.getSourceRootForFile(file);
-    }
-    return myProjectFileIndex.getClassRootForFile(file);
+    VirtualFile root = myProjectFileIndex.getClassRootForFile(file);
+    return root != null ? root : myProjectFileIndex.getSourceRootForFile(file);
   }
 
   @TestOnly