Fixed IDEA-208441 "//region" matches a wrong "//endregion" sometimes

GitOrigin-RevId: f2980e2d92050c5d4c90485955afe4365a033439

java/java-tests/testData/codeInsight/folding/CustomFoldingIdea208441.java

@@ -0,0 +1,9 @@
+public class Test {
+  <fold text='First'>// region First
+  <fold text='//...'>//    void foo() {
+  //        // region MyRegion
+  //        System.out.print("Text");
+  //        // endregion
+  //    }</fold>
+  // endregion</fold>
+}

java/java-tests/testSrc/com/intellij/openapi/editor/impl/JavaFoldingTest.groovy

@@ -16,7 +16,6 @@ import com.intellij.openapi.editor.ex.DocumentEx
 import com.intellij.openapi.editor.ex.EditorEx
 import com.intellij.openapi.editor.ex.FoldingListener
 import com.intellij.openapi.editor.ex.FoldingModelEx
-import com.intellij.openapi.fileEditor.impl.text.TextEditorProvider
 import com.intellij.psi.JavaPsiFacade
 import com.intellij.psi.PsiClass
 import com.intellij.psi.PsiMethod
@@ -382,6 +381,9 @@ class Test {
   }
 
   public void testCustomFolding() { doTest() }
+
+  public void testCustomFoldingIdea208441() {doTest()}
+
   public void testEmptyMethod() { doTest() }
 
   private doTest() {

platform/lang-impl/src/com/intellij/lang/customFolding/VisualStudioCustomFoldingProvider.java

@@ -31,7 +31,7 @@ public class VisualStudioCustomFoldingProvider extends CustomFoldingProvider {
 
   @Override
   public boolean isCustomRegionEnd(String elementText) {
-    return elementText.contains("endregion");
+    return elementText.contains("endregion") && elementText.matches("[/*#-]*\\s*endregion.*");
   }
 
   @Override