Fixes #23541: Multiline Ctrl+D does not work in CRLF files

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

@@ -525,7 +525,7 @@ function multiCursorFind(editor: editorCommon.ICommonCodeEditor, input: IMultiCu
 			searchText = word.word;
 			currentMatch = new Selection(s.startLineNumber, word.startColumn, s.startLineNumber, word.endColumn);
 		} else {
-			searchText = editor.getModel().getValueInRange(s);
+			searchText = editor.getModel().getValueInRange(s).replace(/\r\n/g, '\n');
 		}
 		if (input.changeFindSearchString) {
 			controller.setSearchString(searchText);

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

@@ -9,7 +9,7 @@ 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 { IRange } from 'vs/editor/common/editorCommon';
+import { IRange, EndOfLineSequence } from 'vs/editor/common/editorCommon';
 import {
 	CommonFindController, FindStartFocusAction, IFindStartOptions,
 	NextMatchFindAction, StartFindAction, SelectHighlightsAction,
@@ -350,6 +350,40 @@ suite('FindController', () => {
 		});
 	});
 
+	test('issue #23541: Multiline Ctrl+D does not work in CRLF files', () => {
+		withMockCodeEditor([
+			'',
+			'qwe',
+			'rty',
+			'',
+			'qwe',
+			'',
+			'rty',
+			'qwe',
+			'rty'
+		], {}, (editor, cursor) => {
+
+			editor.getModel().setEOL(EndOfLineSequence.CRLF);
+
+			let findController = editor.registerAndInstantiateContribution<TestFindController>(TestFindController);
+			let addSelectionToNextFindMatch = new AddSelectionToNextFindMatchAction();
+
+			editor.setSelection(new Selection(2, 1, 3, 4));
+
+			addSelectionToNextFindMatch.run(null, editor);
+			assert.deepEqual(editor.getSelections().map(fromRange), [
+				[2, 1, 3, 4],
+				[8, 1, 9, 4]
+			]);
+
+			editor.trigger('test', 'removeSecondaryCursors', null);
+
+			assert.deepEqual(fromRange(editor.getSelection()), [2, 1, 3, 4]);
+
+			findController.dispose();
+		});
+	});
+
 	test('issue #18111: Regex replace with single space replaces with no space', () => {
 		withMockCodeEditor([
 			'HRESULT OnAmbientPropertyChange(DISPID   dispid);'