Duplicate correct line with multiple carets at the start of lines (IJPL-53908)

GitOrigin-RevId: 8fa331c9d78792b58fcbbd277c8baa0a262c0cab

platform/lang-impl/src/com/intellij/codeInsight/editorActions/moveLeftRight/MoveElementLeftRightActionHandler.java

@@ -33,7 +33,7 @@ public final class MoveElementLeftRightActionHandler extends EditorWriteActionHa
   }
 
   @Override
-  protected boolean reverseCaretOrder() {
+  public boolean reverseCaretOrder() {
     return !myIsLeft;
   }
 

platform/lang-impl/src/com/intellij/codeInsight/editorActions/moveUpDown/BaseMoveHandler.java

@@ -27,7 +27,7 @@ public abstract class BaseMoveHandler extends EditorWriteActionHandler.ForEachCa
   }
 
   @Override
-  protected boolean reverseCaretOrder() {
+  public boolean reverseCaretOrder() {
     return isDown;
   }
 

platform/lang-impl/src/com/intellij/openapi/editor/actions/NamedElementDuplicateHandler.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.openapi.editor.actions;
 
 import com.intellij.openapi.actionSystem.DataContext;
@@ -31,6 +31,14 @@ public final class NamedElementDuplicateHandler extends EditorWriteActionHandler
     return myOriginal.isEnabled(editor, caret, dataContext);
   }
 
+  @Override
+  public boolean reverseCaretOrder() {
+    if (myOriginal instanceof EditorWriteActionHandler handler) {
+      return handler.reverseCaretOrder();
+    }
+    return false;
+  }
+
   @Override
   public void executeWriteAction(@NotNull Editor editor, @NotNull Caret caret, DataContext dataContext) {
     Project project = editor.getProject();
@@ -63,8 +71,8 @@ public final class NamedElementDuplicateHandler extends EditorWriteActionHandler
       if (range == null || psi instanceof PsiFile || !toDuplicate.contains(psi.getTextRange())) {
         break;
       }
-      if (psi instanceof PsiNameIdentifierOwner) {
-        named = ((PsiNameIdentifierOwner)psi).getNameIdentifier();
+      if (psi instanceof PsiNameIdentifierOwner owner) {
+        named = owner.getNameIdentifier();
       }
       psi = psi.getParent();
     }

platform/platform-api/api-dump-unreviewed.txt

@@ -2046,7 +2046,7 @@ a:com.intellij.openapi.editor.actionSystem.EditorActionHandler
 - isEnabled(com.intellij.openapi.editor.Editor,com.intellij.openapi.actionSystem.DataContext):Z
 - f:isEnabled(com.intellij.openapi.editor.Editor,com.intellij.openapi.editor.Caret,com.intellij.openapi.actionSystem.DataContext):Z
 - p:isEnabledForCaret(com.intellij.openapi.editor.Editor,com.intellij.openapi.editor.Caret,com.intellij.openapi.actionSystem.DataContext):Z
-- p:reverseCaretOrder():Z
+- reverseCaretOrder():Z
 - runForAllCarets():Z
 a:com.intellij.openapi.editor.actionSystem.EditorActionHandler$ForEachCaret
 - com.intellij.openapi.editor.actionSystem.EditorActionHandler

platform/platform-api/src/com/intellij/openapi/editor/actionSystem/DynamicEditorActionHandler.java

@@ -42,7 +42,7 @@ final class DynamicEditorActionHandler extends EditorActionHandler {
   }
 
   @Override
-  protected boolean reverseCaretOrder() {
+  public boolean reverseCaretOrder() {
     return getHandler().reverseCaretOrder();
   }
 

platform/platform-api/src/com/intellij/openapi/editor/actionSystem/EditorActionHandler.java

@@ -179,7 +179,7 @@ public abstract class EditorActionHandler {
     return myRunForEachCaret;
   }
 
-  protected boolean reverseCaretOrder() {
+  public boolean reverseCaretOrder() {
     return false;
   }
 

platform/platform-impl/src/com/intellij/openapi/editor/actions/DuplicateAction.java

@@ -1,5 +1,4 @@
-// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
-
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.openapi.editor.actions;
 
 import com.intellij.openapi.actionSystem.DataContext;
@@ -26,6 +25,11 @@ public final class DuplicateAction extends EditorAction {
     public boolean isEnabledForCaret(@NotNull Editor editor, @NotNull Caret caret, DataContext dataContext) {
       return !editor.isOneLineMode() || editor.getSelectionModel().hasSelection();
     }
+
+    @Override
+    public boolean reverseCaretOrder() {
+      return true;
+    }
   }
 
   public static void duplicateLineOrSelectedBlockAtCaret(Editor editor) {

platform/platform-impl/src/com/intellij/openapi/editor/actions/DuplicateLinesAction.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.openapi.editor.actions;
 
 import com.intellij.openapi.actionSystem.DataContext;
@@ -36,5 +36,10 @@ public final class DuplicateLinesAction extends EditorAction {
         DuplicateAction.duplicateLinesRange(editor, caretPos, caretPos);
       }
     }
+
+    @Override
+    public boolean reverseCaretOrder() {
+      return true;
+    }
   }
 }

platform/platform-tests/testSrc/com/intellij/openapi/editor/actions/EditorActionTest.java

@@ -1,6 +1,4 @@
-/*
- * Copyright 2000-2017 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
- */
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.openapi.editor.actions;
 
 import com.intellij.openapi.actionSystem.ActionManager;
@@ -283,6 +281,30 @@ public class EditorActionTest extends AbstractEditorTest {
     executeAction(IdeActions.ACTION_EDITOR_DUPLICATE_LINES);
     checkResultByText("ab\ncd\n<selection>ab\ncd</selection>");
   }
+
+  public void testDuplicateLinesMultiCaretLineStart() {
+    String before = """
+      <caret>one
+      <caret>two
+      <caret>three
+      """;
+    String after = """
+      one
+      <caret>one
+      two
+      <caret>two
+      three
+      <caret>three
+      """;
+
+    initText(before);
+    executeAction(IdeActions.ACTION_EDITOR_DUPLICATE_LINES);
+    checkResultByText(after);
+
+    initText(before);
+    ctrlD();
+    checkResultByText(after);
+  }
   
   public void testDuplicateLineWithGuardedBlock() {
     initText("a\n#");