Fixes #80736

src/vs/editor/common/commands/shiftCommand.ts

@@ -179,7 +179,7 @@ export class ShiftCommand implements ICommand {
 				}
 
 				this._addEditOperation(builder, new Range(lineNumber, 1, lineNumber, indentationEndIndex + 1), desiredIndent);
-				if (lineNumber === startLine) {
+				if (lineNumber === startLine && !this._selection.isEmpty()) {
 					// Force the startColumn to stay put because we're inserting after it
 					this._selectionStartColumnStaysPut = (this._selection.startColumn <= indentationEndIndex + 1);
 				}
@@ -226,7 +226,7 @@ export class ShiftCommand implements ICommand {
 					this._addEditOperation(builder, new Range(lineNumber, 1, lineNumber, indentationEndIndex + 1), '');
 				} else {
 					this._addEditOperation(builder, new Range(lineNumber, 1, lineNumber, 1), oneIndent);
-					if (lineNumber === startLine) {
+					if (lineNumber === startLine && !this._selection.isEmpty()) {
 						// Force the startColumn to stay put because we're inserting after it
 						this._selectionStartColumnStaysPut = (this._selection.startColumn === 1);
 					}

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

@@ -928,6 +928,28 @@ suite('Editor Contrib - Line Operations', () => {
 		model.dispose();
 	});
 
+	test('issue #80736: Indenting while the cursor is at the start of a line of text causes the added spaces or tab to be selected', () => {
+		const model = createTextModel(
+			[
+				'Some text'
+			].join('\n'),
+			{
+				insertSpaces: false,
+			}
+		);
+
+		withTestCodeEditor(null, { model: model }, (editor) => {
+			const indentLinesAction = new IndentLinesAction();
+			editor.setPosition(new Position(1, 1));
+
+			indentLinesAction.run(null!, editor);
+			assert.equal(model.getLineContent(1), '\tSome text');
+			assert.deepEqual(editor.getSelection(), new Selection(1, 2, 1, 2));
+		});
+
+		model.dispose();
+	});
+
 	test('issue #62112: Delete line does not work properly when multiple cursors are on line', () => {
 		const TEXT = [
 			'a',

src/vs/editor/test/browser/commands/shiftCommand.test.ts

@@ -92,7 +92,7 @@ suite('Editor Commands - ShiftCommand', () => {
 				'',
 				'123'
 			],
-			new Selection(1, 1, 1, 2)
+			new Selection(1, 2, 1, 2)
 		);
 	});