IDEA-104560 Duplicating the first line with line-wrapping enabled does not work well

platform/platform-impl/src/com/intellij/openapi/editor/ex/util/EditorUtil.java

@@ -718,7 +718,7 @@ public final class EditorUtil {
     LogicalPosition first = editor.visualToLogicalPosition(new VisualPosition(start.line, 0));
     for (
       int line = first.line, offset = document.getLineStartOffset(line);
-      offset > 0;
+      offset >= 0;
       offset = document.getLineStartOffset(line))
     {
       final FoldRegion foldRegion = foldingModel.getCollapsedRegionAtOffset(offset);

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

@@ -17,6 +17,7 @@ package com.intellij.openapi.editor.actions;
 
 import com.intellij.openapi.editor.EditorSettings;
 import com.intellij.openapi.editor.impl.AbstractEditorTest;
+import com.intellij.testFramework.EditorTestUtil;
 import com.intellij.testFramework.TestFileType;
 
 public class EditorActionTest extends AbstractEditorTest {
@@ -53,4 +54,13 @@ public class EditorActionTest extends AbstractEditorTest {
       editorSettings.setCaretInsideTabs(old);
     }
   }
+
+  public void testDuplicateFirstLineWhenSoftWrapsAreOn() throws Exception {
+    init("long long t<caret>ext", TestFileType.TEXT);
+    EditorTestUtil.configureSoftWraps(myEditor, 10);
+
+    executeAction("EditorDuplicate");
+    checkResultByText("long long text\n" +
+                      "long long t<caret>ext");
+  }
 }