fix(layouts): recover from resurrection crash and pick up swap layouts properly (#3249)

* fix(layouts): recover from issues in the constraint system

* fix(keybinds): pick up swap layouts for new tab keybinding

zellij-server/src/tab/layout_applier.rs

@@ -124,11 +124,19 @@ impl<'a> LayoutApplier<'a> {
         refocus_pane: bool,
         client_id: Option<ClientId>,
     ) -> Result<()> {
-        let err_context = || format!("failed to apply tiled panes layout");
         let free_space = self.total_space_for_tiled_panes();
         let tiled_panes_count = self.tiled_panes.visible_panes_count();
-        match layout.position_panes_in_space(&free_space, Some(tiled_panes_count)) {
-            Ok(positions_in_layout) => {
+        let positions_in_layout =
+            match layout.position_panes_in_space(&free_space, Some(tiled_panes_count), false) {
+                Ok(positions_in_layout) => positions_in_layout,
+                // in the error branch, we try to recover by positioning the panes in the space but
+                // ignoring the percentage sizes (passing true as the third argument), this is a hack
+                // around some issues with the constraint system that should be addressed in a systemic
+                // manner
+                Err(_e) => layout
+                    .position_panes_in_space(&free_space, Some(tiled_panes_count), true)
+                    .map_err(|e| anyhow!(e))?,
+            };
         let currently_focused_pane_id =
             client_id.and_then(|client_id| self.tiled_panes.focused_pane_id(client_id));
         let mut existing_tab_state =
@@ -149,8 +157,7 @@ impl<'a> LayoutApplier<'a> {
                         Some(position_and_size),
                     );
                     pane_focuser.set_pane_id_in_focused_location(layout.focus, &pane);
-                            pane_focuser
-                                .set_expanded_stacked_pane(layout.is_expanded_in_stack, &pane);
+                    pane_focuser.set_expanded_stacked_pane(layout.is_expanded_in_stack, &pane);
                     resize_pty!(pane, self.os_api, self.senders, self.character_cell_size)?;
                     self.tiled_panes
                         .add_pane_with_existing_geom(pane.pid(), pane);
@@ -168,11 +175,7 @@ impl<'a> LayoutApplier<'a> {
                 layout.focus.unwrap_or(false),
                 true,
             ) {
-                        self.apply_layout_properties_to_pane(
-                            &mut pane,
-                            &layout,
-                            Some(position_and_size),
-                        );
+                self.apply_layout_properties_to_pane(&mut pane, &layout, Some(position_and_size));
                 pane_focuser.set_pane_id_in_focused_location(layout.focus, &pane);
                 pane_focuser.set_expanded_stacked_pane(layout.is_expanded_in_stack, &pane);
                 resize_pty!(pane, self.os_api, self.senders, self.character_cell_size)?;
@@ -193,13 +196,6 @@ impl<'a> LayoutApplier<'a> {
             self.tiled_panes,
             self.draw_pane_frames,
         );
-            },
-            Err(e) => {
-                Err::<(), _>(anyError::msg(e))
-                    .with_context(err_context)
-                    .non_fatal(); // TODO: propagate this to the user
-            },
-        };
         Ok(())
     }
     fn apply_tiled_panes_layout(
@@ -211,8 +207,17 @@ impl<'a> LayoutApplier<'a> {
     ) -> Result<()> {
         let err_context = || format!("failed to apply tiled panes layout");
         let free_space = self.total_space_for_tiled_panes();
-        match layout.position_panes_in_space(&free_space, None) {
-            Ok(mut positions_in_layout) => {
+        let mut positions_in_layout = match layout.position_panes_in_space(&free_space, None, false)
+        {
+            Ok(positions_in_layout) => positions_in_layout,
+            // in the error branch, we try to recover by positioning the panes in the space but
+            // ignoring the percentage sizes (passing true as the third argument), this is a hack
+            // around some issues with the constraint system that should be addressed in a systemic
+            // manner
+            Err(_e) => layout
+                .position_panes_in_space(&free_space, None, true)
+                .map_err(|e| anyhow!(e))?,
+        };
         let mut run_instructions_to_ignore = layout.run_instructions_to_ignore.clone();
         let mut new_terminal_ids = new_terminal_ids.iter();
 
@@ -337,10 +342,8 @@ impl<'a> LayoutApplier<'a> {
                     if let Some(held_command) = hold_for_command {
                         new_pane.hold(None, true, held_command.clone());
                     }
-                            self.tiled_panes.add_pane_with_existing_geom(
-                                PaneId::Terminal(*pid),
-                                Box::new(new_pane),
-                            );
+                    self.tiled_panes
+                        .add_pane_with_existing_geom(PaneId::Terminal(*pid), Box::new(new_pane));
                     set_focus_pane_id(layout, PaneId::Terminal(*pid));
                 }
             }
@@ -352,18 +355,6 @@ impl<'a> LayoutApplier<'a> {
         }
         self.adjust_viewport().with_context(err_context)?;
         self.set_focused_tiled_pane(focus_pane_id, client_id);
-            },
-            Err(e) => {
-                for (unused_pid, _) in new_terminal_ids {
-                    self.senders
-                        .send_to_pty(PtyInstruction::ClosePane(PaneId::Terminal(unused_pid)))
-                        .with_context(err_context)?;
-                }
-                Err::<(), _>(anyError::msg(e))
-                    .with_context(err_context)
-                    .non_fatal(); // TODO: propagate this to the user
-            },
-        };
         Ok(())
     }
     fn apply_floating_panes_layout(

zellij-server/src/tab/swap_layouts.rs

@@ -249,7 +249,7 @@ impl SwapLayouts {
                             let pane_count = tiled_panes.visible_panes_count();
                             let display_area = PaneGeom::from(&*display_area);
                             if layout
-                                .position_panes_in_space(&display_area, Some(pane_count))
+                                .position_panes_in_space(&display_area, Some(pane_count), false)
                                 .is_ok()
                             {
                                 return Some(layout.clone());
@@ -279,7 +279,7 @@ impl SwapLayouts {
                 let pane_count = tiled_panes.visible_panes_count();
                 let display_area = PaneGeom::from(&*display_area);
                 if layout
-                    .position_panes_in_space(&display_area, Some(pane_count))
+                    .position_panes_in_space(&display_area, Some(pane_count), false)
                     .is_ok()
                 {
                     return Some(layout.clone());

zellij-utils/src/input/layout.rs

@@ -849,6 +849,7 @@ impl TiledPaneLayout {
         &self,
         space: &PaneGeom,
         max_panes: Option<usize>,
+        ignore_percent_split_sizes: bool,
     ) -> Result<Vec<(TiledPaneLayout, PaneGeom)>, &'static str> {
         let layouts = match max_panes {
             Some(max_panes) => {
@@ -874,9 +875,9 @@ impl TiledPaneLayout {
                     layout_to_split.focus_deepest_pane();
                 }
 
-                split_space(space, &layout_to_split, space)?
+                split_space(space, &layout_to_split, space, ignore_percent_split_sizes)?
             },
-            None => split_space(space, self, space)?,
+            None => split_space(space, self, space, ignore_percent_split_sizes)?,
         };
         for (_pane_layout, pane_geom) in layouts.iter() {
             if !pane_geom.is_at_least_minimum_size() {
@@ -1426,6 +1427,7 @@ fn split_space(
     space_to_split: &PaneGeom,
     layout: &TiledPaneLayout,
     total_space_to_split: &PaneGeom,
+    ignore_percent_split_sizes: bool,
 ) -> Result<Vec<(TiledPaneLayout, PaneGeom)>, &'static str> {
     let sizes: Vec<Option<SplitSize>> = if layout.children_are_stacked {
         let index_of_expanded_pane = layout.children.iter().position(|p| p.is_expanded_in_stack);
@@ -1440,6 +1442,15 @@ fn split_space(
             *last_size = None;
         }
         sizes
+    } else if ignore_percent_split_sizes {
+        layout
+            .children
+            .iter()
+            .map(|part| match part.split_size {
+                Some(SplitSize::Percent(_)) => None,
+                split_size => split_size,
+            })
+            .collect()
     } else {
         layout.children.iter().map(|part| part.split_size).collect()
     };
@@ -1539,8 +1550,12 @@ fn split_space(
     for (i, part) in layout.children.iter().enumerate() {
         let part_position_and_size = split_geom.get(i).unwrap();
         if !part.children.is_empty() {
-            let mut part_positions =
-                split_space(part_position_and_size, part, total_space_to_split)?;
+            let mut part_positions = split_space(
+                part_position_and_size,
+                part,
+                total_space_to_split,
+                ignore_percent_split_sizes,
+            )?;
             pane_positions.append(&mut part_positions);
         } else {
             let part = part.clone();

zellij-utils/src/kdl/mod.rs

@@ -860,6 +860,9 @@ impl TryFrom<(&KdlNode, &Options)> for Action {
                     )
                 })?;
 
+                let swap_tiled_layouts = Some(layout.swap_tiled_layouts.clone());
+                let swap_floating_layouts = Some(layout.swap_floating_layouts.clone());
+
                 let mut tabs = layout.tabs();
                 if tabs.len() > 1 {
                     return Err(ConfigError::new_kdl_error(
@@ -874,8 +877,8 @@ impl TryFrom<(&KdlNode, &Options)> for Action {
                     Ok(Action::NewTab(
                         Some(layout),
                         floating_panes_layout,
-                        None,
-                        None,
+                        swap_tiled_layouts,
+                        swap_floating_layouts,
                         name,
                     ))
                 } else {
@@ -884,8 +887,8 @@ impl TryFrom<(&KdlNode, &Options)> for Action {
                     Ok(Action::NewTab(
                         Some(layout),
                         floating_panes_layout,
-                        None,
-                        None,
+                        swap_tiled_layouts,
+                        swap_floating_layouts,
                         name,
                     ))
                 }

zellij-utils/src/pane_size.rs

@@ -122,7 +122,7 @@ impl Dimension {
         self.inner += by;
     }
     pub fn decrease_inner(&mut self, by: usize) {
-        self.inner -= by;
+        self.inner = self.inner.saturating_sub(by);
     }
 
     pub fn is_fixed(&self) -> bool {