Fixes #5400

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

@@ -803,16 +803,31 @@ export class MoveSelectionToPreviousFindMatchAction extends SelectPreviousFindMa
 
 export abstract class AbstractSelectHighlightsAction extends EditorAction {
 	public run(accessor: ServicesAccessor, editor: editorCommon.ICommonCodeEditor): void {
-		let r = multiCursorFind(editor, {
-			changeFindSearchString: true,
-			allowMultiline: true,
-			highlightFindOptions: true
-		});
-		if (!r) {
-			return;
+		let controller = CommonFindController.get(editor);
+		if (!controller) {
+			return null;
 		}
 
-		let matches = editor.getModel().findMatches(r.searchText, true, false, r.matchCase, r.wholeWord, false).map(m => m.range);
+		let matches: Range[] = null;
+
+		const findState = controller.getState();
+		if (findState.isRegex && findState.searchString.length > 0) {
+
+			matches = editor.getModel().findMatches(findState.searchString, true, findState.isRegex, findState.matchCase, findState.wholeWord, false).map(m => m.range);
+
+		} else {
+
+			let r = multiCursorFind(editor, {
+				changeFindSearchString: true,
+				allowMultiline: true,
+				highlightFindOptions: true
+			});
+			if (!r) {
+				return;
+			}
+
+			matches = editor.getModel().findMatches(r.searchText, true, false, r.matchCase, r.wholeWord, false).map(m => m.range);
+		}
 
 		if (matches.length > 0) {
 			let editorSelection = editor.getSelection();

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

@@ -215,6 +215,33 @@ suite('FindController', () => {
 		});
 	});
 
+	test('issue #5400: "Select All Occurences of Find Match" does not select all if find uses regex', () => {
+		withMockCodeEditor([
+			'something',
+			'someething',
+			'someeething',
+			'nothing'
+		], { serviceCollection: serviceCollection }, (editor, cursor) => {
+
+			let findController = editor.registerAndInstantiateContribution<TestFindController>(TestFindController);
+			let selectHighlightsAction = new SelectHighlightsAction();
+
+			editor.setSelection(new Selection(1, 1, 1, 1));
+			findController.getState().change({ searchString: 'some+thing', isRegex: true }, false);
+
+			selectHighlightsAction.run(null, editor);
+			assert.deepEqual(editor.getSelections().map(fromRange), [
+				[1, 1, 1, 10],
+				[2, 1, 2, 11],
+				[3, 1, 3, 12],
+			]);
+
+			assert.equal(findController.getState().searchString, 'some+thing');
+
+			findController.dispose();
+		});
+	});
+
 	test('issue #9043: Clear search scope when find widget is hidden', () => {
 		withMockCodeEditor([
 			'var x = (3 * 5)',