Fixes #6661: Relax cursor merging rules in case of touching ranges

src/vs/editor/common/controller/cursorCollection.ts

@@ -202,7 +202,16 @@ export class CursorCollection {
 			const currentViewSelection = current.viewSelection;
 			const nextViewSelection = next.viewSelection;
 
-			if (nextViewSelection.getStartPosition().isBeforeOrEqual(currentViewSelection.getEndPosition())) {
+			let shouldMergeCursors: boolean;
+			if (nextViewSelection.isEmpty() || currentViewSelection.isEmpty()) {
+				// Merge touching cursors if one of them is collapsed
+				shouldMergeCursors = nextViewSelection.getStartPosition().isBeforeOrEqual(currentViewSelection.getEndPosition());
+			} else {
+				// Merge only overlapping cursors (i.e. allow touching ranges)
+				shouldMergeCursors = nextViewSelection.getStartPosition().isBefore(currentViewSelection.getEndPosition());
+			}
+
+			if (shouldMergeCursors) {
 				const winnerSortedCursorIndex = current.index < next.index ? sortedCursorIndex : sortedCursorIndex + 1;
 				const looserSortedCursorIndex = current.index < next.index ? sortedCursorIndex + 1 : sortedCursorIndex;
 

src/vs/editor/contrib/find/test/common/findController.test.ts

@@ -11,7 +11,7 @@ import { EditOperation } from 'vs/editor/common/core/editOperation';
 import { Position } from 'vs/editor/common/core/position';
 import { Selection } from 'vs/editor/common/core/selection';
 import { Range } from 'vs/editor/common/core/range';
-import { EndOfLineSequence, ICommonCodeEditor } from 'vs/editor/common/editorCommon';
+import { EndOfLineSequence, ICommonCodeEditor, Handler } from 'vs/editor/common/editorCommon';
 import {
 	CommonFindController, FindStartFocusAction, IFindStartOptions,
 	NextMatchFindAction, StartFindAction, SelectHighlightsAction,
@@ -412,6 +412,53 @@ suite('FindController', () => {
 		});
 	});
 
+	test('issue #6661: AddSelectionToNextFindMatchAction can work with touching ranges', () => {
+		withMockCodeEditor([
+			'abcabc',
+			'abc',
+			'abcabc',
+		], { serviceCollection: serviceCollection }, (editor, cursor) => {
+
+			let findController = editor.registerAndInstantiateContribution<TestFindController>(TestFindController);
+			let addSelectionToNextFindMatch = new AddSelectionToNextFindMatchAction();
+
+			editor.setSelection(new Selection(1, 1, 1, 4));
+
+			addSelectionToNextFindMatch.run(null, editor);
+			assert.deepEqual(editor.getSelections().map(fromRange), [
+				[1, 1, 1, 4],
+				[1, 4, 1, 7]
+			]);
+
+			addSelectionToNextFindMatch.run(null, editor);
+			addSelectionToNextFindMatch.run(null, editor);
+			addSelectionToNextFindMatch.run(null, editor);
+			assert.deepEqual(editor.getSelections().map(fromRange), [
+				[1, 1, 1, 4],
+				[1, 4, 1, 7],
+				[2, 1, 2, 4],
+				[3, 1, 3, 4],
+				[3, 4, 3, 7]
+			]);
+
+			editor.trigger('test', Handler.Type, { text: 'z' });
+			assert.deepEqual(editor.getSelections().map(fromRange), [
+				[1, 2, 1, 2],
+				[1, 3, 1, 3],
+				[2, 2, 2, 2],
+				[3, 2, 3, 2],
+				[3, 3, 3, 3]
+			]);
+			assert.equal(editor.getValue(), [
+				'zz',
+				'z',
+				'zz',
+			].join('\n'));
+
+			findController.dispose();
+		});
+	});
+
 	test('issue #23541: Multiline Ctrl+D does not work in CRLF files', () => {
 		withMockCodeEditor([
 			'',