fix(stacked-panes): better handling of adding new panes to a stack (#4016)

* fix(stacked-panes): better handling of adding new panes to a stack

* style(fmt): rustfmt

* docs(changelog): document

9 files changed, 32 insertions, 16 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index dcdae5fc..829bbd10 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,7 +21,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 * fix(terminal): support setting kitty keyboard protocol with `CSI=` (https://github.com/zellij-org/zellij/pull/3942)
 * fix(floating-panes): handle various errors (https://github.com/zellij-org/zellij/pull/3944)
 * chore(rust): Update Rust toolchain to 1.84.0 (https://github.com/zellij-org/zellij/pull/3945)
-* feat(ux): stacked-resize (https://github.com/zellij-org/zellij/pull/3957, https://github.com/zellij-org/zellij/pull/4003 and https://github.com/zellij-org/zellij/pull/4011)
+* feat(ux): stacked-resize (https://github.com/zellij-org/zellij/pull/3957, https://github.com/zellij-org/zellij/pull/4003, https://github.com/zellij-org/zellij/pull/4011 and https://github.com/zellij-org/zellij/pull/4016)
 * feat(plugins): API to change the position and size of floating pane, as well as know the viewport size (https://github.com/zellij-org/zellij/pull/3958 and https://github.com/zellij-org/zellij/pull/3972)
 * feat(plugins): add `PastedText` event (https://github.com/zellij-org/zellij/pull/3962)
 * feat(plugins): APIs to open panes near plugin (https://github.com/zellij-org/zellij/pull/3966)
diff --git a/zellij-server/src/panes/tiled_panes/mod.rs b/zellij-server/src/panes/tiled_panes/mod.rs
index 40048cfd..42bbe7f7 100644
--- a/zellij-server/src/panes/tiled_panes/mod.rs
+++ b/zellij-server/src/panes/tiled_panes/mod.rs
@@ -355,8 +355,12 @@ impl TiledPanes {
                         self.panes.insert(pane_id, pane); // TODO: is set_geom the right one?
                         return;
                     },
-                    Err(e) => {
-                        log::error!("Failed to add pane to stack: {:?}", e);
+                    Err(_e) => {
+                        return self.add_pane_without_stacked_resize(
+                            pane_id,
+                            pane,
+                            should_relayout,
+                        );
                     },
                 }
             },
diff --git a/zellij-server/src/panes/tiled_panes/stacked_panes.rs b/zellij-server/src/panes/tiled_panes/stacked_panes.rs
index 748e4fc6..81d15ea3 100644
--- a/zellij-server/src/panes/tiled_panes/stacked_panes.rs
+++ b/zellij-server/src/panes/tiled_panes/stacked_panes.rs
@@ -1,4 +1,7 @@
-use crate::{panes::PaneId, tab::Pane};
+use crate::{
+    panes::PaneId,
+    tab::{Pane, MIN_TERMINAL_HEIGHT},
+};
 use std::cell::RefCell;
 use std::collections::{HashMap, HashSet};
 use std::rc::Rc;
@@ -419,7 +422,7 @@ impl<'a> StackedPanes<'a> {
         for stack in all_stacks {
             if let Some((id_of_flexible_pane_in_stack, _flexible_pane_in_stack)) = stack
                 .iter()
-                .find(|(_p_id, p)| !p.rows.is_fixed() && p.rows.as_usize() > 1)
+                .find(|(_p_id, p)| !p.rows.is_fixed() && p.rows.as_usize() > MIN_TERMINAL_HEIGHT)
             {
                 self.make_lowest_pane_in_stack_flexible(id_of_flexible_pane_in_stack)?;
                 let all_stacked_pane_positions =
@@ -452,7 +455,7 @@ impl<'a> StackedPanes<'a> {
         let stack = self.positions_in_stack(pane_id).with_context(err_context)?;
         if let Some((id_of_flexible_pane_in_stack, _flexible_pane_in_stack)) = stack
             .iter()
-            .find(|(_p_id, p)| !p.rows.is_fixed() && p.rows.as_usize() > 1)
+            .find(|(_p_id, p)| !p.rows.is_fixed() && p.rows.as_usize() > MIN_TERMINAL_HEIGHT)
         {
             self.make_lowest_pane_in_stack_flexible(id_of_flexible_pane_in_stack)?;
             let all_stacked_pane_positions =
diff --git a/zellij-server/src/panes/tiled_panes/tiled_pane_grid.rs b/zellij-server/src/panes/tiled_panes/tiled_pane_grid.rs
index 03581f16..5f2bf834 100644
--- a/zellij-server/src/panes/tiled_panes/tiled_pane_grid.rs
+++ b/zellij-server/src/panes/tiled_panes/tiled_pane_grid.rs
@@ -1411,7 +1411,7 @@ impl<'a> TiledPaneGrid<'a> {
             .collect();
         flexible_pane_in_stack
             .iter()
-            .any(|(_p_id, p)| p.current_geom().rows.as_usize() > 1)
+            .any(|(_p_id, p)| p.current_geom().rows.as_usize() > MIN_TERMINAL_HEIGHT)
     }
     pub fn make_room_in_stack_for_pane(&mut self) -> Result<PaneGeom> {
         StackedPanes::new(self.panes.clone()).make_room_for_new_pane()
diff --git a/zellij-server/src/tab/mod.rs b/zellij-server/src/tab/mod.rs
index 71bb3bea..75032fff 100644
--- a/zellij-server/src/tab/mod.rs
+++ b/zellij-server/src/tab/mod.rs
@@ -825,7 +825,7 @@ impl Tab {
             .swap_layouts
             .swap_tiled_panes(&self.tiled_panes, search_backwards)
         {
-            LayoutApplier::new(
+            let application_res = LayoutApplier::new(
                 &self.viewport,
                 &self.senders,
                 &self.sixel_image_store,
@@ -846,8 +846,13 @@ impl Tab {
                 self.styled_underlines,
                 self.explicitly_disable_kitty_keyboard_protocol,
             )
-            .apply_tiled_panes_layout_to_existing_panes(&layout_candidate)
-            .non_fatal();
+            .apply_tiled_panes_layout_to_existing_panes(&layout_candidate);
+            if application_res.is_err() {
+                self.swap_layouts.set_is_tiled_damaged();
+                application_res.non_fatal();
+            }
+        } else {
+            self.swap_layouts.set_is_tiled_damaged();
         }
         self.tiled_panes.reapply_pane_frames();
         let display_area = *self.display_area.borrow();
diff --git a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__screen_can_move_pane_to_a_new_tab_left-4.snap b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__screen_can_move_pane_to_a_new_tab_left-4.snap
index 112a5705..77c5a5a3 100644
--- a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__screen_can_move_pane_to_a_new_tab_left-4.snap
+++ b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__screen_can_move_pane_to_a_new_tab_left-4.snap
@@ -1,9 +1,9 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 3636
+assertion_line: 3649
 expression: "format!(\"{}\", snapshot)"
 ---
-00 (C): ┌ pane_to_break_free ──────────────────┐┌ pane_to_stay ────────────────────────┐
+00 (C): ┌ pane_to_stay ────────────────────────┐┌ pane_to_break_free ──────────────────┐
 01 (C): │                                      ││                                      │
 02 (C): │                                      ││                                      │
 03 (C): │                                      ││                                      │
diff --git a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__screen_can_move_pane_to_a_new_tab_right-4.snap b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__screen_can_move_pane_to_a_new_tab_right-4.snap
index 8a3cfe42..ef8a4d90 100644
--- a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__screen_can_move_pane_to_a_new_tab_right-4.snap
+++ b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__screen_can_move_pane_to_a_new_tab_right-4.snap
@@ -1,9 +1,9 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 3587
+assertion_line: 3601
 expression: "format!(\"{}\", snapshot)"
 ---
-00 (C): ┌ pane_to_break_free ──────────────────┐┌ pane_to_stay ────────────────────────┐
+00 (C): ┌ pane_to_stay ────────────────────────┐┌ pane_to_break_free ──────────────────┐
 01 (C): │                                      ││                                      │
 02 (C): │                                      ││                                      │
 03 (C): │                                      ││                                      │
diff --git a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_toggle_pane_embed_or_float-3.snap b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_toggle_pane_embed_or_float-3.snap
index f2bcd76f..5a16d92e 100644
--- a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_toggle_pane_embed_or_float-3.snap
+++ b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_toggle_pane_embed_or_float-3.snap
@@ -1,9 +1,9 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 2569
+assertion_line: 2583
 expression: "format!(\"{}\", snapshot)"
 ---
-00 (C): ┌ Pane #1 ─────────────────────────────┐┌ Pane #2 ─────────────────────────────┐
+00 (C): ┌ Pane #2 ─────────────────────────────┐┌ Pane #1 ─────────────────────────────┐
 01 (C): │                                      ││                                      │
 02 (C): │                                      ││                                      │
 03 (C): │                                      ││                                      │
diff --git a/zellij-utils/src/input/layout.rs b/zellij-utils/src/input/layout.rs
index f69975fc..8e3dbd53 100644
--- a/zellij-utils/src/input/layout.rs
+++ b/zellij-utils/src/input/layout.rs
@@ -1631,6 +1631,10 @@ fn split_space(
         } else if let Some(last_size) = sizes.last_mut() {
             *last_size = None;
         }
+        if sizes.len() > space_to_split.rows.as_usize().saturating_sub(4) {
+            // 4 is MIN_TERMINAL_HEIGHT
+            return Err("Not enough room for stacked panes in this layout");
+        }
         sizes
     } else if ignore_percent_split_sizes {
         layout