fix #50670

src/vs/workbench/browser/parts/editor/editor.ts

@@ -35,7 +35,7 @@ export const DEFAULT_EDITOR_PART_OPTIONS: IEditorPartOptions = {
 	showIcons: true,
 	enablePreview: true,
 	openPositioning: 'right',
-	openSideBySideDirection: 'horizontal',
+	openSideBySideDirection: 'right',
 	closeEmptyGroups: true,
 	labelFormat: 'default',
 	iconTheme: 'vs-seti'

src/vs/workbench/common/editor.ts

@@ -947,7 +947,7 @@ export interface IWorkbenchEditorPartConfiguration {
 	enablePreviewFromQuickOpen?: boolean;
 	closeOnFileDelete?: boolean;
 	openPositioning?: 'left' | 'right' | 'first' | 'last';
-	openSideBySideDirection?: 'horizontal' | 'vertical';
+	openSideBySideDirection?: 'right' | 'down';
 	closeEmptyGroups?: boolean;
 	revealIfOpen?: boolean;
 	swipeToNavigate?: boolean;

src/vs/workbench/electron-browser/main.contribution.ts

@@ -218,9 +218,9 @@ configurationRegistry.registerConfiguration({
 		},
 		'workbench.editor.openSideBySideDirection': {
 			'type': 'string',
-			'enum': ['horizontal', 'vertical'],
-			'default': 'horizontal',
-			'description': nls.localize('sideBySideDirection', "Controls the default direction of editors that are opened side by side (e.g. from the explorer). By default, editors will open horizontally on the rigth hand side of the currently active one. If changed to open vertically, the editors will open below the currently active one.")
+			'enum': ['right', 'down'],
+			'default': 'right',
+			'description': nls.localize('sideBySideDirection', "Controls the default direction of editors that are opened side by side (e.g. from the explorer). By default, editors will open on the rigth hand side of the currently active one. If changed to open down, the editors will open below the currently active one.")
 		},
 		'workbench.editor.closeEmptyGroups': {
 			'type': 'boolean',

src/vs/workbench/services/group/common/editorGroupsService.ts

@@ -22,9 +22,9 @@ export enum GroupDirection {
 }
 
 export function preferredSideBySideGroupDirection(configurationService: IConfigurationService): GroupDirection.DOWN | GroupDirection.RIGHT {
-	const openSideBySideDirection = configurationService.getValue<'horizontal' | 'vertical'>('workbench.editor.openSideBySideDirection');
+	const openSideBySideDirection = configurationService.getValue<'right' | 'down'>('workbench.editor.openSideBySideDirection');
 
-	if (openSideBySideDirection === 'vertical') {
+	if (openSideBySideDirection === 'down') {
 		return GroupDirection.DOWN;
 	}