git: Fix panic in git2 due to empty repo paths (#42304)

Fixes ZED-1VR

Release Notes:

- Fixed sporadic panic in git features

crates/git/src/repository.rs

@@ -14,7 +14,6 @@ use rope::Rope;
 use schemars::JsonSchema;
 use serde::Deserialize;
 use smol::io::{AsyncBufReadExt, AsyncReadExt, BufReader};
-use std::borrow::Cow;
 use std::ffi::{OsStr, OsString};
 use std::process::{ExitStatus, Stdio};
 use std::{
@@ -848,7 +847,7 @@ impl GitRepository for RealGitRepository {
                 }
 
                 files.push(CommitFile {
-                    path: rel_path.into(),
+                    path: RepoPath(Arc::from(rel_path)),
                     old_text,
                     new_text,
                 })
@@ -2049,6 +2048,11 @@ fn git_status_args(path_prefixes: &[RepoPath]) -> Vec<OsString> {
         OsString::from("--no-renames"),
         OsString::from("-z"),
     ];
+    args.extend(
+        path_prefixes
+            .iter()
+            .map(|path_prefix| path_prefix.as_std_path().into()),
+    );
     args.extend(path_prefixes.iter().map(|path_prefix| {
         if path_prefix.is_empty() {
             Path::new(".").into()
@@ -2304,23 +2308,43 @@ async fn run_askpass_command(
     }
 }
 
-#[derive(Clone, Debug, Ord, Hash, PartialOrd, Eq, PartialEq)]
-pub struct RepoPath(pub Arc<RelPath>);
+#[derive(Clone, Ord, Hash, PartialOrd, Eq, PartialEq)]
+pub struct RepoPath(Arc<RelPath>);
+
+impl std::fmt::Debug for RepoPath {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
 
 impl RepoPath {
     pub fn new<S: AsRef<str> + ?Sized>(s: &S) -> Result<Self> {
         let rel_path = RelPath::unix(s.as_ref())?;
-        Ok(rel_path.into())
-    }
-
-    pub fn from_proto(proto: &str) -> Result<Self> {
-        let rel_path = RelPath::from_proto(proto)?;
-        Ok(rel_path.into())
+        Ok(Self::from_rel_path(rel_path))
     }
 
     pub fn from_std_path(path: &Path, path_style: PathStyle) -> Result<Self> {
         let rel_path = RelPath::new(path, path_style)?;
-        Ok(Self(rel_path.as_ref().into()))
+        Ok(Self::from_rel_path(&rel_path))
+    }
+
+    pub fn from_proto(proto: &str) -> Result<Self> {
+        let rel_path = RelPath::from_proto(proto)?;
+        Ok(Self(rel_path))
+    }
+
+    pub fn from_rel_path(path: &RelPath) -> RepoPath {
+        Self(Arc::from(path))
+    }
+
+    pub fn as_std_path(&self) -> &Path {
+        // git2 does not like empty paths and our RelPath infra turns `.` into ``
+        // so undo that here
+        if self.is_empty() {
+            Path::new(".")
+        } else {
+            self.0.as_std_path()
+        }
     }
 }
 
@@ -2329,27 +2353,9 @@ pub fn repo_path<S: AsRef<str> + ?Sized>(s: &S) -> RepoPath {
     RepoPath(RelPath::unix(s.as_ref()).unwrap().into())
 }
 
-impl From<&RelPath> for RepoPath {
-    fn from(value: &RelPath) -> Self {
-        RepoPath(value.into())
-    }
-}
-
-impl<'a> From<Cow<'a, RelPath>> for RepoPath {
-    fn from(value: Cow<'a, RelPath>) -> Self {
-        value.as_ref().into()
-    }
-}
-
-impl From<Arc<RelPath>> for RepoPath {
-    fn from(value: Arc<RelPath>) -> Self {
-        RepoPath(value)
-    }
-}
-
-impl Default for RepoPath {
-    fn default() -> Self {
-        RepoPath(RelPath::empty().into())
+impl AsRef<Arc<RelPath>> for RepoPath {
+    fn as_ref(&self) -> &Arc<RelPath> {
+        &self.0
     }
 }
 
@@ -2361,12 +2367,6 @@ impl std::ops::Deref for RepoPath {
     }
 }
 
-// impl AsRef<Path> for RepoPath {
-//     fn as_ref(&self) -> &Path {
-//         RelPath::as_ref(&self.0)
-//     }
-// }
-
 #[derive(Debug)]
 pub struct RepoPathDescendants<'a>(pub &'a RepoPath);
 

crates/git/src/status.rs

@@ -454,7 +454,7 @@ impl FromStr for GitStatus {
                 let status = entry.as_bytes()[0..2].try_into().unwrap();
                 let status = FileStatus::from_bytes(status).log_err()?;
                 // git-status outputs `/`-delimited repo paths, even on Windows.
-                let path = RepoPath(RelPath::unix(path).log_err()?.into());
+                let path = RepoPath::from_rel_path(RelPath::unix(path).log_err()?);
                 Some((path, status))
             })
             .collect::<Vec<_>>();
@@ -539,7 +539,7 @@ impl FromStr for TreeDiff {
         let mut fields = s.split('\0');
         let mut parsed = HashMap::default();
         while let Some((status, path)) = fields.next().zip(fields.next()) {
-            let path = RepoPath(RelPath::unix(path)?.into());
+            let path = RepoPath::from_rel_path(RelPath::unix(path)?);
 
             let mut fields = status.split(" ").skip(2);
             let old_sha = fields