prevent scm from moving on startup (#99692)

Author: sbatten

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

@@ -122,7 +122,8 @@ export class CompositeDragAndDrop implements ICompositeDragAndDrop {
 			const draggedViews = this.viewDescriptorService.getViewContainerModel(currentContainer)!.allViewDescriptors;
 
 			// ... all views must be movable
-			return !draggedViews.some(v => !v.canMoveView);
+			// Prevent moving scm explicitly TODO@joaomoreno remove when scm is moveable
+			return !draggedViews.some(v => !v.canMoveView) && currentContainer.id !== 'workbench.view.scm';
 		} else {
 			// Dragging an individual view
 			const viewDescriptor = this.viewDescriptorService.getViewDescriptorById(dragData.id);

src/vs/workbench/browser/parts/views/viewPaneContainer.ts

@@ -913,7 +913,7 @@ export class ViewPaneContainer extends Component implements IViewPaneContainer {
 						const container = this.viewDescriptorService.getViewContainerById(dropData.id)!;
 						const viewsToMove = this.viewDescriptorService.getViewContainerModel(container).allViewDescriptors;
 
-						if (!viewsToMove.some(v => !v.canMoveView)) {
+						if (!viewsToMove.some(v => !v.canMoveView) && viewsToMove.length > 0) {
 							overlay = new ViewPaneDropOverlay(parent, undefined, this.viewDescriptorService.getViewContainerLocation(this.viewContainer)!, this.themeService);
 						}
 					}
@@ -1353,7 +1353,7 @@ export class ViewPaneContainer extends Component implements IViewPaneContainer {
 						const container = this.viewDescriptorService.getViewContainerById(dropData.id)!;
 						const viewsToMove = this.viewDescriptorService.getViewContainerModel(container).allViewDescriptors;
 
-						if (!viewsToMove.some(v => !v.canMoveView)) {
+						if (!viewsToMove.some(v => !v.canMoveView) && viewsToMove.length > 0) {
 							overlay = new ViewPaneDropOverlay(pane.dropTargetElement, this.orientation ?? Orientation.VERTICAL, this.viewDescriptorService.getViewContainerLocation(this.viewContainer)!, this.themeService);
 						}
 					}