From f28cc5ca0c7224f1fed578c2a081c1579edb795a Mon Sep 17 00:00:00 2001
From: Antonio Scandurra <me@as-cii.com>
Date: Thu, 13 Oct 2022 09:10:10 +0200
Subject: [PATCH] Preserve buffer identity when underlying entry temporarily
 disappears

---
 crates/project/src/project.rs       | 13 +++++++------
 crates/project/src/project_tests.rs |  1 +
 crates/project/src/worktree.rs      | 23 ++++++++++++++++-------
 crates/rpc/proto/zed.proto          |  3 ++-
 4 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/crates/project/src/project.rs b/crates/project/src/project.rs
index 17e0d5fafe..ea74dda434 100644
--- a/crates/project/src/project.rs
+++ b/crates/project/src/project.rs
@@ -4298,34 +4298,35 @@ impl Project {
                             return;
                         }
 
-                        let new_file = if let Some(entry) = old_file
-                            .entry_id
-                            .and_then(|entry_id| snapshot.entry_for_id(entry_id))
+                        let new_file = if let Some(entry) = snapshot.entry_for_id(old_file.entry_id)
                         {
                             File {
                                 is_local: true,
-                                entry_id: Some(entry.id),
+                                entry_id: entry.id,
                                 mtime: entry.mtime,
                                 path: entry.path.clone(),
                                 worktree: worktree_handle.clone(),
+                                is_deleted: false,
                             }
                         } else if let Some(entry) =
                             snapshot.entry_for_path(old_file.path().as_ref())
                         {
                             File {
                                 is_local: true,
-                                entry_id: Some(entry.id),
+                                entry_id: entry.id,
                                 mtime: entry.mtime,
                                 path: entry.path.clone(),
                                 worktree: worktree_handle.clone(),
+                                is_deleted: false,
                             }
                         } else {
                             File {
                                 is_local: true,
-                                entry_id: None,
+                                entry_id: old_file.entry_id,
                                 path: old_file.path().clone(),
                                 mtime: old_file.mtime(),
                                 worktree: worktree_handle.clone(),
+                                is_deleted: true,
                             }
                         };
 
diff --git a/crates/project/src/project_tests.rs b/crates/project/src/project_tests.rs
index 702f28fc59..72f4778a38 100644
--- a/crates/project/src/project_tests.rs
+++ b/crates/project/src/project_tests.rs
@@ -2457,6 +2457,7 @@ async fn test_buffer_is_dirty(cx: &mut gpui::TestAppContext) {
         .await
         .unwrap();
     cx.foreground().run_until_parked();
+    buffer2.read_with(cx, |buffer, _| assert!(buffer.is_dirty()));
     assert_eq!(
         *events.borrow(),
         &[
diff --git a/crates/project/src/worktree.rs b/crates/project/src/worktree.rs
index f0e9aa7934..383c9ac35b 100644
--- a/crates/project/src/worktree.rs
+++ b/crates/project/src/worktree.rs
@@ -688,11 +688,12 @@ impl LocalWorktree {
 
             Ok((
                 File {
-                    entry_id: Some(entry.id),
+                    entry_id: entry.id,
                     worktree: handle,
                     path: entry.path,
                     mtime: entry.mtime,
                     is_local: true,
+                    is_deleted: false,
                 },
                 text,
                 diff_base,
@@ -715,11 +716,12 @@ impl LocalWorktree {
         cx.as_mut().spawn(|mut cx| async move {
             let entry = save.await?;
             let file = File {
-                entry_id: Some(entry.id),
+                entry_id: entry.id,
                 worktree: handle,
                 path: entry.path,
                 mtime: entry.mtime,
                 is_local: true,
+                is_deleted: false,
             };
 
             buffer_handle.update(&mut cx, |buffer, cx| {
@@ -1813,8 +1815,9 @@ pub struct File {
     pub worktree: ModelHandle<Worktree>,
     pub path: Arc<Path>,
     pub mtime: SystemTime,
-    pub(crate) entry_id: Option<ProjectEntryId>,
+    pub(crate) entry_id: ProjectEntryId,
     pub(crate) is_local: bool,
+    pub(crate) is_deleted: bool,
 }
 
 impl language::File for File {
@@ -1852,7 +1855,7 @@ impl language::File for File {
     }
 
     fn is_deleted(&self) -> bool {
-        self.entry_id.is_none()
+        self.is_deleted
     }
 
     fn save(
@@ -1912,9 +1915,10 @@ impl language::File for File {
     fn to_proto(&self) -> rpc::proto::File {
         rpc::proto::File {
             worktree_id: self.worktree.id() as u64,
-            entry_id: self.entry_id.map(|entry_id| entry_id.to_proto()),
+            entry_id: self.entry_id.to_proto(),
             path: self.path.to_string_lossy().into(),
             mtime: Some(self.mtime.into()),
+            is_deleted: self.is_deleted,
         }
     }
 }
@@ -1983,8 +1987,9 @@ impl File {
             worktree,
             path: Path::new(&proto.path).into(),
             mtime: proto.mtime.ok_or_else(|| anyhow!("no timestamp"))?.into(),
-            entry_id: proto.entry_id.map(ProjectEntryId::from_proto),
+            entry_id: ProjectEntryId::from_proto(proto.entry_id),
             is_local: false,
+            is_deleted: proto.is_deleted,
         })
     }
 
@@ -1997,7 +2002,11 @@ impl File {
     }
 
     pub fn project_entry_id(&self, _: &AppContext) -> Option<ProjectEntryId> {
-        self.entry_id
+        if self.is_deleted {
+            None
+        } else {
+            Some(self.entry_id)
+        }
     }
 }
 
diff --git a/crates/rpc/proto/zed.proto b/crates/rpc/proto/zed.proto
index 283b11fd78..1248bb0551 100644
--- a/crates/rpc/proto/zed.proto
+++ b/crates/rpc/proto/zed.proto
@@ -868,9 +868,10 @@ message User {
 
 message File {
     uint64 worktree_id = 1;
-    optional uint64 entry_id = 2;
+    uint64 entry_id = 2;
     string path = 3;
     Timestamp mtime = 4;
+    bool is_deleted = 5;
 }
 
 message Entry {