Preserve gone state information of RemoteTrackingBranch

src/branch.rs

@@ -33,16 +33,16 @@ impl LocalBranch {
         &self,
         repo: &Repository,
         config: &Config,
-    ) -> Result<Option<RemoteTrackingBranch>> {
+    ) -> Result<RemoteTrackingBranchStatus> {
         let remote_name = if let Some(remote_name) = config::get_remote_name(config, self)? {
             remote_name
         } else {
-            return Ok(None);
+            return Ok(RemoteTrackingBranchStatus::None);
         };
         let merge: String = if let Some(merge) = config::get_merge(config, self)? {
             merge
         } else {
-            return Ok(None);
+            return Ok(RemoteTrackingBranchStatus::None);
         };
 
         RemoteTrackingBranch::from_remote_branch(
@@ -99,7 +99,7 @@ impl RemoteTrackingBranch {
     pub fn from_remote_branch(
         repo: &Repository,
         remote_branch: &RemoteBranch,
-    ) -> Result<Option<RemoteTrackingBranch>> {
+    ) -> Result<RemoteTrackingBranchStatus> {
         let remote = config::get_remote(repo, &remote_branch.remote)?;
         if let Some(remote) = remote {
             let refname = if let Some(expanded) = expand_refspec(
@@ -110,16 +110,18 @@ impl RemoteTrackingBranch {
             )? {
                 expanded
             } else {
-                return Ok(None);
+                return Ok(RemoteTrackingBranchStatus::None);
             };
 
             if repo.find_reference(&refname).is_ok() {
-                return Ok(Some(RemoteTrackingBranch::new(&refname)));
+                return Ok(RemoteTrackingBranchStatus::Exists(
+                    RemoteTrackingBranch::new(&refname),
+                ));
             } else {
-                return Ok(None);
+                return Ok(RemoteTrackingBranchStatus::Gone(refname));
             }
         }
-        Ok(None)
+        Ok(RemoteTrackingBranchStatus::None)
     }
 
     pub fn to_remote_branch(
@@ -173,6 +175,12 @@ impl<'repo> TryFrom<&git2::Reference<'repo>> for RemoteTrackingBranch {
     }
 }
 
+pub enum RemoteTrackingBranchStatus {
+    Exists(RemoteTrackingBranch),
+    Gone(String),
+    None,
+}
+
 #[derive(Eq, PartialEq, Ord, PartialOrd, Clone, Hash, Debug)]
 pub struct RemoteBranch {
     pub remote: String,

src/config.rs

@@ -9,7 +9,7 @@ use git2::{BranchType, Config as GitConfig, Error, ErrorClass, ErrorCode, Remote
 use log::*;
 
 use crate::args::{Args, DeleteFilter, DeleteRange, ScanFilter, ScanRange};
-use crate::branch::LocalBranch;
+use crate::branch::{LocalBranch, RemoteTrackingBranchStatus};
 use std::collections::HashSet;
 
 type GitResult<T> = std::result::Result<T, git2::Error>;
@@ -106,7 +106,9 @@ fn get_branches_tracks_remote_heads(repo: &Repository, config: &GitConfig) -> Re
             let (branch, _) = branch?;
             let branch = LocalBranch::try_from(&branch)?;
 
-            if let Some(upstream) = branch.fetch_upstream(repo, config)? {
+            if let RemoteTrackingBranchStatus::Exists(upstream) =
+                branch.fetch_upstream(repo, config)?
+            {
                 if upstream.refname == refname {
                     result.push(branch.short_name().to_owned());
                 }

src/core.rs

@@ -7,7 +7,7 @@ use log::*;
 use rayon::prelude::*;
 
 use crate::args::DeleteFilter;
-use crate::branch::{LocalBranch, RemoteBranch, RemoteTrackingBranch};
+use crate::branch::{LocalBranch, RemoteBranch, RemoteTrackingBranch, RemoteTrackingBranchStatus};
 use crate::merge_tracker::{MergeState, MergeTracker};
 use crate::subprocess::{self, get_worktrees, RemoteHead};
 use crate::util::ForceSendSync;
@@ -350,7 +350,9 @@ pub fn classify(
     branch: &LocalBranch,
 ) -> Result<Classification> {
     let local = merge_tracker.check_and_track(&git.repo, &base.refname, branch)?;
-    let fetch = if let Some(fetch) = branch.fetch_upstream(&git.repo, &git.config)? {
+    let fetch = if let RemoteTrackingBranchStatus::Exists(fetch) =
+        branch.fetch_upstream(&git.repo, &git.config)?
+    {
         Some(merge_tracker.check_and_track(&git.repo, &base.refname, &fetch)?)
     } else {
         None
@@ -459,7 +461,7 @@ pub fn get_tracking_branches(
         }
 
         let fetch_upstream = branch.fetch_upstream(&git.repo, &git.config)?;
-        if let Some(upstream) = &fetch_upstream {
+        if let RemoteTrackingBranchStatus::Exists(upstream) = &fetch_upstream {
             if base_upstreams.contains(&upstream) {
                 debug!("Skip: the branch tracks the base: {:?}", branch);
                 continue;
@@ -509,7 +511,7 @@ pub fn get_non_upstream_remote_tracking_branches(
     let tracking_branches = get_tracking_branches(git, base_upstreams)?;
     for tracking_branch in tracking_branches {
         let upstream = tracking_branch.fetch_upstream(&git.repo, &git.config)?;
-        if let Some(upstream) = upstream {
+        if let RemoteTrackingBranchStatus::Exists(upstream) = upstream {
             upstreams.insert(upstream);
         }
     }

src/lib.rs

@@ -17,6 +17,7 @@ use glob::Pattern;
 use log::*;
 
 use crate::args::{DeleteFilter, ScanFilter};
+use crate::branch::RemoteTrackingBranchStatus;
 pub use crate::branch::{LocalBranch, RemoteBranch, RemoteBranchError, RemoteTrackingBranch};
 use crate::core::{
     get_non_tracking_local_branches, get_non_upstream_remote_tracking_branches, get_remote_heads,
@@ -225,7 +226,9 @@ fn resolve_base_and_upstream_refs(
         if reference.is_branch() {
             let refname = reference.name().context("non utf-8 base refname")?;
             let branch = LocalBranch::new(refname);
-            if let Some(upstream) = branch.fetch_upstream(repo, config)? {
+            if let RemoteTrackingBranchStatus::Exists(upstream) =
+                branch.fetch_upstream(repo, config)?
+            {
                 result.insert(upstream.refname);
             }
         }
@@ -256,7 +259,9 @@ fn resolve_base_upstreams(
             };
 
             if let Ok(branch) = LocalBranch::try_from(&reference) {
-                if let Some(upstream) = branch.fetch_upstream(repo, config)? {
+                if let RemoteTrackingBranchStatus::Exists(upstream) =
+                    branch.fetch_upstream(repo, config)?
+                {
                     result.push(upstream);
                     continue;
                 }
@@ -314,7 +319,9 @@ fn resolve_protected_refs(
             if Pattern::new(protected_branch)?.matches(branch_name) {
                 let branch = LocalBranch::try_from(&branch)?;
                 result.insert(branch.refname.to_string());
-                if let Some(upstream) = branch.fetch_upstream(repo, config)? {
+                if let RemoteTrackingBranchStatus::Exists(upstream) =
+                    branch.fetch_upstream(repo, config)?
+                {
                     result.insert(upstream.refname);
                 }
             }

src/subprocess.rs

@@ -5,7 +5,7 @@ use anyhow::{Context, Result};
 use git2::{Config, Reference, Repository};
 use log::*;
 
-use crate::branch::{LocalBranch, RemoteBranch, RemoteTrackingBranch};
+use crate::branch::{LocalBranch, RemoteBranch, RemoteTrackingBranch, RemoteTrackingBranchStatus};
 
 fn git(repo: &Repository, args: &[&str], level: log::Level) -> Result<()> {
     let workdir = repo.workdir().context("Bare repository is not supported")?;
@@ -103,8 +103,10 @@ pub fn get_noff_merged_locals(
             }
             let branch = LocalBranch::new(refname);
             let upstream = branch.fetch_upstream(repo, config)?;
-            if Some(base) == upstream.as_ref() {
-                continue;
+            if let RemoteTrackingBranchStatus::Exists(upstream) = upstream {
+                if base == &upstream {
+                    continue;
+                }
             }
             let reference = repo.find_reference(&refname)?;
             if reference.symbolic_target().is_some() {