Merge fe635735b6 into 09165c15dc

crates/project/src/project.rs

@@ -4625,6 +4625,32 @@ impl Project {
         })
     }
 
+    /// Moves multiple worktrees as a group to `destination`'s position,
+    /// preserving their relative order.
+    pub fn move_worktrees(
+        &mut self,
+        sources: &[WorktreeId],
+        destination: WorktreeId,
+        active_source: Option<WorktreeId>,
+        cx: &mut Context<Self>,
+    ) -> Result<()> {
+        self.worktree_store.update(cx, |worktree_store, cx| {
+            worktree_store.move_worktrees(sources, destination, active_source, cx)
+        })
+    }
+
+    /// Moves multiple worktrees to the end of the worktree list, preserving
+    /// their relative order.
+    pub fn move_worktrees_to_end(
+        &mut self,
+        sources: &[WorktreeId],
+        cx: &mut Context<Self>,
+    ) -> Result<()> {
+        self.worktree_store.update(cx, |worktree_store, cx| {
+            worktree_store.move_worktrees_to_end(sources, cx)
+        })
+    }
+
     /// Attempts to convert the input path to a WSL path if this is a wsl remote project and the input path is a host windows path.
     pub fn try_windows_path_to_wsl(
         &self,

crates/project/src/worktree_store.rs

@@ -1038,42 +1038,159 @@ impl WorktreeStore {
         destination: WorktreeId,
         cx: &mut Context<Self>,
     ) -> Result<()> {
-        if source == destination {
+        self.move_worktrees(&[source], destination, Some(source), cx)
+    }
+
+    /// Moves multiple worktrees as a group to `destination`'s position,
+    /// preserving their relative order. The `active_source` (if provided and
+    /// in `sources`) decides whether the group lands before or after the
+    /// destination, mirroring the single-source semantics: a source originally
+    /// before destination ends up after it, and vice versa. When no usable
+    /// active source is supplied, the earliest source in the current worktree
+    /// order is used as the direction reference.
+    pub fn move_worktrees(
+        &mut self,
+        sources: &[WorktreeId],
+        destination: WorktreeId,
+        active_source: Option<WorktreeId>,
+        cx: &mut Context<Self>,
+    ) -> Result<()> {
+        if sources.is_empty() {
+            return Ok(());
+        }
+        // Self-drop of any selection member is a no-op: the user dropping a
+        // multi-selection onto one of its own roots has no well-defined
+        // intent.
+        if sources.contains(&destination) {
             return Ok(());
         }
 
-        let mut source_index = None;
+        let destination_index = self
-        let mut destination_index = None;
+            .worktrees
-        for (i, worktree) in self.worktrees.iter().enumerate() {
+            .iter()
-            if let Some(worktree) = worktree.upgrade() {
+            .position(|wt| {
-                let worktree_id = worktree.read(cx).id();
+                wt.upgrade()
-                if worktree_id == source {
+                    .is_some_and(|wt| wt.read(cx).id() == destination)
-                    source_index = Some(i);
+            })
-                    if destination_index.is_some() {
+            .with_context(|| format!("Missing worktree for id {destination}"))?;
-                        break;
+
-                    }
+        for &source in sources {
-                } else if worktree_id == destination {
+            if !self
-                    destination_index = Some(i);
+                .worktrees
-                    if source_index.is_some() {
+                .iter()
-                        break;
+                .any(|wt| wt.upgrade().is_some_and(|wt| wt.read(cx).id() == source))
-                    }
+            {
-                }
+                anyhow::bail!("Missing worktree for id {source}");
             }
         }
 
-        let source_index =
+        let source_indices: Vec<usize> = self
-            source_index.with_context(|| format!("Missing worktree for id {source}"))?;
+            .worktrees
-        let destination_index =
+            .iter()
-            destination_index.with_context(|| format!("Missing worktree for id {destination}"))?;
+            .enumerate()
+            .filter_map(|(i, wt)| {
+                let id = wt.upgrade()?.read(cx).id();
+                sources.contains(&id).then_some(i)
+            })
+            .collect();
 
-        if source_index == destination_index {
+        if source_indices.is_empty() {
             return Ok(());
         }
 
-        let worktree_to_move = self.worktrees.remove(source_index);
+        let direction_index = active_source
-        self.worktrees.insert(destination_index, worktree_to_move);
+            .filter(|id| sources.contains(id))
+            .and_then(|id| {
+                self.worktrees
+                    .iter()
+                    .position(|wt| wt.upgrade().is_some_and(|wt| wt.read(cx).id() == id))
+            })
+            .unwrap_or(source_indices[0]);
+        let insert_after_destination = direction_index < destination_index;
+
+        let mut to_insert = Vec::with_capacity(source_indices.len());
+        for &i in source_indices.iter().rev() {
+            to_insert.push(self.worktrees.remove(i));
+        }
+        to_insert.reverse();
+
+        let removed_before_destination = source_indices
+            .iter()
+            .filter(|&&i| i < destination_index)
+            .count();
+        let new_destination_index = destination_index - removed_before_destination;
+        let insert_at = if insert_after_destination {
+            new_destination_index + 1
+        } else {
+            new_destination_index
+        };
+
+        for (offset, handle) in to_insert.into_iter().enumerate() {
+            self.worktrees.insert(insert_at + offset, handle);
+        }
+
         cx.emit(WorktreeStoreEvent::WorktreeOrderChanged);
         cx.notify();
+        self.send_project_updates(cx);
+        Ok(())
+    }
+
+    /// Removes every source from the worktree list and appends them to the
+    /// end in their original relative order. Returns early when the sources
+    /// already form a contiguous suffix.
+    pub fn move_worktrees_to_end(
+        &mut self,
+        sources: &[WorktreeId],
+        cx: &mut Context<Self>,
+    ) -> Result<()> {
+        if sources.is_empty() {
+            return Ok(());
+        }
+
+        for &source in sources {
+            if !self
+                .worktrees
+                .iter()
+                .any(|wt| wt.upgrade().is_some_and(|wt| wt.read(cx).id() == source))
+            {
+                anyhow::bail!("Missing worktree for id {source}");
+            }
+        }
+
+        let source_indices: Vec<usize> = self
+            .worktrees
+            .iter()
+            .enumerate()
+            .filter_map(|(i, wt)| {
+                let id = wt.upgrade()?.read(cx).id();
+                sources.contains(&id).then_some(i)
+            })
+            .collect();
+
+        if source_indices.is_empty() {
+            return Ok(());
+        }
+
+        // Already a contiguous suffix → nothing to do.
+        let len = self.worktrees.len();
+        let already_at_end = source_indices
+            .iter()
+            .enumerate()
+            .all(|(offset, &i)| i == len - source_indices.len() + offset);
+        if already_at_end {
+            return Ok(());
+        }
+
+        let mut to_append = Vec::with_capacity(source_indices.len());
+        for &i in source_indices.iter().rev() {
+            to_append.push(self.worktrees.remove(i));
+        }
+        to_append.reverse();
+        self.worktrees.extend(to_append);
+
+        cx.emit(WorktreeStoreEvent::WorktreeOrderChanged);
+        cx.notify();
+        self.send_project_updates(cx);
         Ok(())
     }
 

crates/project/tests/integration/project_tests.rs

@@ -9019,6 +9019,130 @@ async fn test_reordering_worktrees(cx: &mut gpui::TestAppContext) {
     });
 }
 
+#[gpui::test]
+async fn test_move_worktrees_to_end(cx: &mut gpui::TestAppContext) {
+    init_test(cx);
+
+    let fs = FakeFs::new(cx.executor());
+    fs.insert_tree(
+        "/dir",
+        json!({
+            "a.rs": "",
+            "b.rs": "",
+            "c.rs": "",
+            "d.rs": "",
+        }),
+    )
+    .await;
+
+    let project = Project::test(
+        fs,
+        [
+            "/dir/a.rs".as_ref(),
+            "/dir/b.rs".as_ref(),
+            "/dir/c.rs".as_ref(),
+            "/dir/d.rs".as_ref(),
+        ],
+        cx,
+    )
+    .await;
+
+    let (a_id, b_id, c_id, d_id) = project.update(cx, |project, cx| {
+        let worktrees = project.visible_worktrees(cx).collect::<Vec<_>>();
+        (
+            worktrees[0].read(cx).id(),
+            worktrees[1].read(cx).id(),
+            worktrees[2].read(cx).id(),
+            worktrees[3].read(cx).id(),
+        )
+    });
+
+    // Non-contiguous selection [a, c] → group lands at end as [b, d, a, c].
+    project
+        .update(cx, |project, cx| {
+            project.move_worktrees_to_end(&[a_id, c_id], cx)
+        })
+        .expect("moving non-contiguous group to end");
+    project.update(cx, |project, cx| {
+        let order: Vec<_> = project
+            .visible_worktrees(cx)
+            .map(|wt| wt.read(cx).id())
+            .collect();
+        assert_eq!(order, vec![b_id, d_id, a_id, c_id]);
+    });
+
+    // Already-suffix selection [a, c] → no-op (current order is [b, d, a, c]).
+    project
+        .update(cx, |project, cx| {
+            project.move_worktrees_to_end(&[a_id, c_id], cx)
+        })
+        .expect("contiguous-suffix call should still succeed");
+    project.update(cx, |project, cx| {
+        let order: Vec<_> = project
+            .visible_worktrees(cx)
+            .map(|wt| wt.read(cx).id())
+            .collect();
+        assert_eq!(order, vec![b_id, d_id, a_id, c_id]);
+    });
+
+    // Single source [b] → moves to end: [d, a, c, b].
+    project
+        .update(cx, |project, cx| {
+            project.move_worktrees_to_end(&[b_id], cx)
+        })
+        .expect("moving a single source to end");
+    project.update(cx, |project, cx| {
+        let order: Vec<_> = project
+            .visible_worktrees(cx)
+            .map(|wt| wt.read(cx).id())
+            .collect();
+        assert_eq!(order, vec![d_id, a_id, c_id, b_id]);
+    });
+
+    // Invalid source id → error.
+    project.update(cx, |project, cx| {
+        let invalid = worktree::WorktreeId::from_usize(99_999);
+        assert!(
+            project.move_worktrees_to_end(&[invalid], cx).is_err(),
+            "moving an unknown source should error"
+        );
+    });
+}
+
+#[gpui::test]
+async fn test_move_worktree_with_invalid_source_errors(cx: &mut gpui::TestAppContext) {
+    use worktree::WorktreeId;
+
+    init_test(cx);
+
+    let fs = FakeFs::new(cx.executor());
+    fs.insert_tree(
+        "/dir",
+        json!({
+            "a.rs": "",
+            "b.rs": "",
+        }),
+    )
+    .await;
+
+    let project =
+        Project::test(fs, ["/dir/a.rs".as_ref(), "/dir/b.rs".as_ref()], cx).await;
+
+    project.update(cx, |project, cx| {
+        let valid_id = project.visible_worktrees(cx).next().unwrap().read(cx).id();
+        let invalid_id = WorktreeId::from_usize(99_999);
+
+        assert!(
+            project.move_worktree(invalid_id, valid_id, cx).is_err(),
+            "moving an unknown source worktree should error"
+        );
+        assert!(
+            project.move_worktree(valid_id, invalid_id, cx).is_err(),
+            "moving onto an unknown destination should error"
+        );
+    });
+}
+
 #[gpui::test]
 async fn test_unstaged_diff_for_buffer(cx: &mut gpui::TestAppContext) {
     init_test(cx);

crates/project_panel/src/project_panel.rs

@@ -3596,48 +3596,94 @@ impl ProjectPanel {
         }
     }
 
-    fn move_entry(
+    fn reorder_worktree_roots(
         &mut self,
-        entry_to_move: ProjectEntryId,
+        source_entries: &[ProjectEntryId],
-        destination: ProjectEntryId,
-        destination_is_file: bool,
-        cx: &mut Context<Self>,
-    ) -> Option<Task<Result<CreatedEntry>>> {
-        if self
-            .project
-            .read(cx)
-            .entry_is_worktree_root(entry_to_move, cx)
-        {
-            self.move_worktree_root(entry_to_move, destination, cx);
-            None
-        } else {
-            self.move_worktree_entry(entry_to_move, destination, destination_is_file, cx)
-        }
-    }
-
-    fn move_worktree_root(
-        &mut self,
-        entry_to_move: ProjectEntryId,
         destination: ProjectEntryId,
+        active_entry_id: ProjectEntryId,
         cx: &mut Context<Self>,
     ) {
         self.project.update(cx, |project, cx| {
-            let Some(worktree_to_move) = project.worktree_for_entry(entry_to_move, cx) else {
+            // Only reorder when the destination resolves to a worktree root.
+            // Nested entries are rejected; the empty area below the panel
+            // resolves to the last worktree's root, which still satisfies
+            // this check.
+            if !project.entry_is_worktree_root(destination, cx) {
                 return;
-            };
+            }
             let Some(destination_worktree) = project.worktree_for_entry(destination, cx) else {
                 return;
             };
-
-            let worktree_id = worktree_to_move.read(cx).id();
             let destination_id = destination_worktree.read(cx).id();
 
+            let source_ids: Vec<WorktreeId> = source_entries
+                .iter()
+                .filter_map(|entry_id| {
+                    project
+                        .worktree_for_entry(*entry_id, cx)
+                        .map(|wt| wt.read(cx).id())
+                })
+                .collect();
+            if source_ids.is_empty() {
+                return;
+            }
+
+            let active_source = project
+                .worktree_for_entry(active_entry_id, cx)
+                .map(|wt| wt.read(cx).id());
+
             project
-                .move_worktree(worktree_id, destination_id, cx)
+                .move_worktrees(&source_ids, destination_id, active_source, cx)
                 .log_err();
         });
     }
 
+    /// Moves all root-only entries in the drag to the end of the worktree
+    /// list. Used by the blank-area drop handler so dropping a multi-root
+    /// selection that already contains the last worktree (e.g. `[A, D]` in
+    /// `[A, B, C, D]`) settles the group at the end instead of falling on
+    /// the self-drop guard in `move_worktrees`.
+    fn reorder_worktree_roots_to_end(
+        &mut self,
+        selections: &DraggedSelection,
+        cx: &mut Context<Self>,
+    ) {
+        self.project.update(cx, |project, cx| {
+            let source_ids: Vec<WorktreeId> = selections
+                .items()
+                .filter_map(|entry| {
+                    project
+                        .worktree_for_entry(entry.entry_id, cx)
+                        .map(|wt| wt.read(cx).id())
+                })
+                .collect();
+            if source_ids.is_empty() {
+                return;
+            }
+            project.move_worktrees_to_end(&source_ids, cx).log_err();
+        });
+    }
+
+    fn drag_includes_last_worktree(&self, selections: &DraggedSelection, cx: &App) -> bool {
+        let project = self.project.read(cx);
+        let drag_is_root_only = selections
+            .items()
+            .all(|entry| project.entry_is_worktree_root(entry.entry_id, cx));
+        if !drag_is_root_only {
+            return false;
+        }
+        let Some(last_worktree_id) = project
+            .visible_worktrees(cx)
+            .next_back()
+            .map(|wt| wt.read(cx).id())
+        else {
+            return false;
+        };
+        selections
+            .items()
+            .any(|entry| entry.worktree_id == last_worktree_id)
+    }
+
     fn move_worktree_entry(
         &mut self,
         entry_to_move: ProjectEntryId,
@@ -3698,7 +3744,13 @@ impl ProjectPanel {
     }
 
     fn disjoint_effective_entries(&self, cx: &App) -> BTreeSet<SelectedEntry> {
-        self.disjoint_entries(self.effective_entries(), cx)
+        let project = self.project.read(cx);
+        let entries = self
+            .effective_entries()
+            .into_iter()
+            .filter(|entry| !project.entry_is_worktree_root(entry.entry_id, cx))
+            .collect();
+        self.disjoint_entries(entries, cx)
     }
 
     fn disjoint_entries(
@@ -3712,22 +3764,25 @@ impl ProjectPanel {
         }
 
         let project = self.project.read(cx);
-        let entries_by_worktree: HashMap<WorktreeId, Vec<SelectedEntry>> = entries
+        let entries_by_worktree: HashMap<WorktreeId, Vec<SelectedEntry>> =
-            .into_iter()
+            entries
-            .filter(|entry| !project.entry_is_worktree_root(entry.entry_id, cx))
+                .into_iter()
-            .fold(HashMap::default(), |mut map, entry| {
+                .fold(HashMap::default(), |mut map, entry| {
-                map.entry(entry.worktree_id).or_default().push(entry);
+                    map.entry(entry.worktree_id).or_default().push(entry);
-                map
+                    map
-            });
+                });
 
         for (worktree_id, worktree_entries) in entries_by_worktree {
             if let Some(worktree) = project.worktree_for_id(worktree_id, cx) {
                 let worktree = worktree.read(cx);
+                // Skip the worktree root: its empty path would consume every
+                // other selected entry in the same worktree as "nested inside
+                // a selected directory" and silently drop them.
                 let dir_paths = worktree_entries
                     .iter()
                     .filter_map(|entry| {
                         worktree.entry_for_id(entry.entry_id).and_then(|entry| {
-                            if entry.is_dir() {
+                            if entry.is_dir() && !entry.path.is_empty() {
                                 Some(entry.path.as_ref())
                             } else {
                                 None
@@ -4420,6 +4475,22 @@ impl ProjectPanel {
         .detach();
     }
 
+    fn handle_drag_modifiers_changed(
+        &mut self,
+        modifiers: &Modifiers,
+        window: &mut Window,
+        cx: &mut Context<Self>,
+    ) {
+        self.refresh_drag_cursor_style(modifiers, window, cx);
+        // The copy modifier flips highlight semantics for worktree-root
+        // drags. Drop the cached target so the next drag-move event
+        // recomputes under the new mode — otherwise the on_drag_move
+        // fast path skips the recomputation while the pointer stays put.
+        if self.drag_target_entry.take().is_some() {
+            cx.notify();
+        }
+    }
+
     fn refresh_drag_cursor_style(
         &self,
         modifiers: &Modifiers,
@@ -4461,6 +4532,18 @@ impl ProjectPanel {
         let entries = self.disjoint_entries(resolved_selections, cx);
 
         if Self::is_copy_modifier_set(&window.modifiers()) {
+            // Worktree roots can't be copied — leaving them in would make
+            // `create_paste_path` return None and `?` would abort the whole copy.
+            let entries: BTreeSet<SelectedEntry> = {
+                let project = self.project.read(cx);
+                entries
+                    .into_iter()
+                    .filter(|entry| !project.entry_is_worktree_root(entry.entry_id, cx))
+                    .collect()
+            };
+            if entries.is_empty() {
+                return;
+            }
             let _ = maybe!({
                 let project = self.project.read(cx);
                 let target_worktree = project.worktree_for_entry(target_entry_id, cx)?;
@@ -4521,6 +4604,27 @@ impl ProjectPanel {
         } else {
             let update_marks = !self.marked_entries.is_empty();
             let active_selection = selections.active_selection;
+            let active_entry_id = self.resolve_entry(active_selection.entry_id);
+
+            // Reorder marked worktree roots together so their relative order is
+            // preserved; non-roots fall through to the normal per-entry move flow.
+            let (root_entry_ids, entries) = {
+                let project = self.project.read(cx);
+                let mut roots = Vec::new();
+                let mut non_roots = BTreeSet::new();
+                for entry in entries {
+                    if project.entry_is_worktree_root(entry.entry_id, cx) {
+                        roots.push(entry.entry_id);
+                    } else {
+                        non_roots.insert(entry);
+                    }
+                }
+                (roots, non_roots)
+            };
+
+            if !root_entry_ids.is_empty() {
+                self.reorder_worktree_roots(&root_entry_ids, target_entry_id, active_entry_id, cx);
+            }
 
             // For folded selections, track the leaf suffix relative to the resolved
             // entry so we can refresh it after the move completes.
@@ -4577,7 +4681,9 @@ impl ProjectPanel {
             // results with folded selections that need refreshing.
             let mut move_tasks: Vec<(ProjectEntryId, Task<Result<CreatedEntry>>)> = Vec::new();
             for entry in entries {
-                if let Some(task) = self.move_entry(entry.entry_id, target_entry_id, is_file, cx) {
+                if let Some(task) =
+                    self.move_worktree_entry(entry.entry_id, target_entry_id, is_file, cx)
+                {
                     move_tasks.push((entry.entry_id, task));
                 }
             }
@@ -5191,8 +5297,36 @@ impl ProjectPanel {
         target_entry: &Entry,
         target_worktree: &Worktree,
         drag_state: &DraggedSelection,
+        is_copy_mode: bool,
         cx: &Context<Self>,
     ) -> Option<ProjectEntryId> {
+        // Pure worktree-root drags are only meaningful when dropped on
+        // another worktree's root; suppress highlights elsewhere. Mixed drags
+        // (e.g. a root with a marked file) fall through so the file portion
+        // can still receive feedback on directory targets.
+        let project = self.project.read(cx);
+        let drag_is_root_only = drag_state
+            .items()
+            .all(|entry| project.entry_is_worktree_root(entry.entry_id, cx));
+        if drag_is_root_only {
+            // Worktree roots can't be copied; in copy mode the drop is a
+            // guaranteed no-op, so don't highlight any target.
+            if is_copy_mode {
+                return None;
+            }
+            let root_id = target_worktree.root_entry()?.id;
+            // Hovering any worktree that's part of the drag (active or just
+            // marked) is a no-op in `move_worktrees`, so don't highlight it.
+            let target_worktree_id = target_worktree.id();
+            let target_in_drag = drag_state
+                .items()
+                .any(|entry| entry.worktree_id == target_worktree_id);
+            if target_entry.id == root_id && !target_in_drag {
+                return Some(root_id);
+            }
+            return None;
+        }
+
         let target_parent_path = target_entry.path.parent();
 
         // In case of single item drag, we do not highlight existing
@@ -5232,19 +5366,28 @@ impl ProjectPanel {
         &self,
         drag_state: &DraggedSelection,
         last_root_id: ProjectEntryId,
+        is_copy_mode: bool,
         cx: &App,
     ) -> bool {
+        let project = self.project.read(cx);
+
+        // Worktree roots can't be copied, so a pure-root copy drag is a
+        // guaranteed no-op — don't advertise the background as a target.
+        if is_copy_mode
+            && drag_state
+                .items()
+                .all(|entry| project.entry_is_worktree_root(entry.entry_id, cx))
+        {
+            return false;
+        }
+
         // Always highlight for multiple entries
         if drag_state.items().count() > 1 {
             return true;
         }
 
         // Since root will always have empty relative path
-        if let Some(entry_path) = self
+        if let Some(entry_path) = project.path_for_entry(drag_state.active_selection.entry_id, cx) {
-            .project
-            .read(cx)
-            .path_for_entry(drag_state.active_selection.entry_id, cx)
-        {
             if let Some(parent_path) = entry_path.path.parent() {
                 if !parent_path.is_empty() {
                     return true;
@@ -5253,11 +5396,7 @@ impl ProjectPanel {
         }
 
         // If parent is empty, check if different worktree
-        if let Some(last_root_worktree_id) = self
+        if let Some(last_root_worktree_id) = project.worktree_id_for_entry(last_root_id, cx) {
-            .project
-            .read(cx)
-            .worktree_id_for_entry(last_root_id, cx)
-        {
             if drag_state.active_selection.worktree_id != last_root_worktree_id {
                 return true;
             }
@@ -5525,6 +5664,7 @@ impl ProjectPanel {
                                 this.marked_entries.push(drag_state.active_selection);
                             }
 
+                            let is_copy_mode = Self::is_copy_modifier_set(&window.modifiers());
                             let Some((entry_id, highlight_entry_id)) = maybe!({
                                 let target_worktree = this
                                     .project
@@ -5537,6 +5677,7 @@ impl ProjectPanel {
                                     target_entry,
                                     target_worktree,
                                     drag_state,
+                                    is_copy_mode,
                                     cx,
                                 )?;
                                 Some((target_entry.id, highlight_entry_id))
@@ -6639,7 +6780,7 @@ impl Render for ProjectPanel {
                 .relative()
                 .on_modifiers_changed(cx.listener(
                     |this, event: &ModifiersChangedEvent, window, cx| {
-                        this.refresh_drag_cursor_style(&event.modifiers, window, cx);
+                        this.handle_drag_modifiers_changed(&event.modifiers, window, cx);
                     },
                 ))
                 .key_context(self.dispatch_context(window, cx))
@@ -6982,16 +7123,23 @@ impl Render for ProjectPanel {
                                     },
                                 ))
                                 .on_drag_move::<DraggedSelection>(cx.listener(
-                                    move |this, event: &DragMoveEvent<DraggedSelection>, _, cx| {
+                                    move |this,
+                                          event: &DragMoveEvent<DraggedSelection>,
+                                          window,
+                                          cx| {
                                         let Some(last_root_id) = this.state.last_worktree_root_id
                                         else {
                                             return;
                                         };
                                         if event.bounds.contains(&event.event.position) {
                                             let drag_state = event.drag(cx);
+                                            let is_copy_mode = Self::is_copy_modifier_set(
+                                                &window.modifiers(),
+                                            );
                                             if this.should_highlight_background_for_selection_drag(
                                                 &drag_state,
                                                 last_root_id,
+                                                is_copy_mode,
                                                 cx,
                                             ) {
                                                 this.drag_target_entry =
@@ -7025,7 +7173,20 @@ impl Render for ProjectPanel {
                                     move |this, selections: &DraggedSelection, window, cx| {
                                         this.drag_target_entry = None;
                                         this.hover_scroll_task.take();
-                                        if let Some(entry_id) = this.state.last_worktree_root_id {
+                                        let is_copy_mode =
+                                            Self::is_copy_modifier_set(&window.modifiers());
+                                        // For move drags whose root group includes the last
+                                        // worktree, route to the move-to-end path so we don't
+                                        // hit the self-drop guard in `move_worktrees`. Copy
+                                        // drags fall through to `drag_onto`, which will
+                                        // filter the roots out as a no-op.
+                                        if !is_copy_mode
+                                            && this.drag_includes_last_worktree(selections, cx)
+                                        {
+                                            this.reorder_worktree_roots_to_end(selections, cx);
+                                        } else if let Some(entry_id) =
+                                            this.state.last_worktree_root_id
+                                        {
                                             this.drag_onto(selections, entry_id, false, window, cx);
                                         }
                                         cx.stop_propagation();