T14c, T15 review fixes: Tab steps past merges, empty charts lay out nothing, flat domains widen by size, pointed parts let go of shrunk data, signed waterfall totals, sunburst children take their share, today stays on the timeline

src/charts/network.rs

@@ -173,7 +173,10 @@ impl RenderOnce for NetworkGraph {
         if !settled {
             window.request_animation_frame();
         }
-        let (bounds, hover) = (graph.read(cx).bounds, graph.read(cx).hover);
+        let (bounds, hover) = (
+            graph.read(cx).bounds,
+            graph.read(cx).hover.filter(|ix| *ix < self.nodes.len()),
+        );
         let theme = cx.theme();
         let (colors, sizes, rem) = (theme.colors.clone(), theme.chart(), window.rem_size());
         let pixels = |length: gpui::Rems| f32::from(length.to_pixels(rem));
@@ -275,6 +278,7 @@ impl RenderOnce for NetworkGraph {
             let offset = position - bounds.origin;
             (f32::from(offset.x), f32::from(offset.y))
         };
+        let count = self.nodes.len();
         let (moved, pressed, released, left, measured) = (
             graph.clone(),
             graph.clone(),
@@ -299,7 +303,8 @@ impl RenderOnce for NetworkGraph {
             .on_mouse_move(move |event: &MouseMoveEvent, _, cx| {
                 let place = local(event.position, moved.read(cx).bounds);
                 moved.update(cx, |graph, cx| {
-                    if let (Some(ix), Some(MouseButton::Left)) = (graph.drag, event.pressed_button)
+                    if let (Some(ix), Some(MouseButton::Left)) =
+                        (graph.drag.filter(|ix| *ix < count), event.pressed_button)
                     {
                         graph
                             .force