Merge from vscode 718331d6f3ebd1b571530ab499edb266ddd493d5

src/vs/editor/contrib/linesOperations/linesOperations.ts

@@ -37,12 +37,36 @@ abstract class AbstractCopyLinesAction extends EditorAction {
 	}
 
 	public run(_accessor: ServicesAccessor, editor: ICodeEditor): void {
+		if (!editor.hasModel()) {
+			return;
+		}
+
+		const selections = editor.getSelections().map((selection, index) => ({ selection, index, ignore: false }));
+		selections.sort((a, b) => Range.compareRangesUsingStarts(a.selection, b.selection));
+
+		// Remove selections that would result in copying the same line
+		let prev = selections[0];
+		for (let i = 1; i < selections.length; i++) {
+			const curr = selections[i];
+			if (prev.selection.endLineNumber === curr.selection.startLineNumber) {
+				// these two selections would copy the same line
+				if (prev.index < curr.index) {
+					// prev wins
+					curr.ignore = true;
+				} else {
+					// curr wins
+					prev.ignore = true;
+					prev = curr;
+				}
+			}
+		}
 
 		const commands: ICommand[] = [];
-		const selections = editor.getSelections() || [];
-
 		for (const selection of selections) {
-			commands.push(new CopyLinesCommand(selection, this.down));
+			if (selection.ignore) {
+				continue;
+			}
+			commands.push(new CopyLinesCommand(selection.selection, this.down));
 		}
 
 		editor.pushUndoStop();