Autosave: a recovery listing judges each key once, so an autosave in progress isn't listed twice (#9324)

* Autosave: a recovery listing judges each key once, so an autosave in progress isn't listed twice

* Autosave: the recovery listing builds for the browser too

crates/format/src/autosave.rs

@@ -9,6 +9,7 @@
 //! [`RecoveryStore`] is the app-facing lifecycle: an entry is only deleted once
 //! the document is saved or closed, never just because it was recovered.
 
+use std::collections::BTreeSet;
 #[cfg(not(target_arch = "wasm32"))]
 use std::collections::HashMap;
 use std::path::{Path, PathBuf};
@@ -247,41 +248,51 @@ fn read_sidecar_bounded(path: &Path, max: usize) -> Option<Vec<u8>> {
 
 /// Recoverable documents in `recovery_dir`, newest first. A sidecar must be named after its own
 /// (sanitized) key, so a stray or hand-edited one can never point outside the directory.
+///
+/// Each key is looked at once, after the directory has been read: an autosave may publish a
+/// document's first sidecar while the listing runs, and judging the bundle and the sidecar as
+/// each name came up listed that bundle twice, or not at all.
 pub fn list_recovery(recovery_dir: &Path) -> Vec<RecoveryEntry> {
-    let mut out = Vec::new();
     let Ok(rd) = std::fs::read_dir(recovery_dir) else {
-        return out;
+        return Vec::new();
     };
-    for e in rd.flatten() {
-        let p = e.path();
-        if e.file_type().is_ok_and(|ft| ft.is_file())
-            && p.extension().is_some_and(|x| x == "json")
-            && let Some(bytes) = read_sidecar_bounded(&p, 1 << 20)
-            && let Ok(info) = serde_json::from_slice::<RecoveryInfo>(&bytes)
-            && sanitize(&info.key) == info.key
-            && p.file_stem().is_some_and(|stem| *stem == *info.key)
-        {
-            let bundle = recovery_dir.join(format!("{}.pcraft", info.key));
-            if bundle.join(crate::store::MANIFEST).is_file() {
-                out.push(RecoveryEntry { info, bundle });
-            }
-        } else if e.file_type().is_ok_and(|ft| ft.is_dir())
-            && let Some(entry) = sidecarless_entry(recovery_dir, &p)
-        {
-            out.push(entry);
-        }
-    }
+    let keys: BTreeSet<String> = rd
+        .flatten()
+        .filter_map(|e| {
+            let name = e.file_name().into_string().ok()?;
+            name.strip_suffix(".json").or_else(|| name.strip_suffix(".pcraft")).map(str::to_string)
+        })
+        .collect();
+    let mut out: Vec<RecoveryEntry> = keys.iter().filter_map(|key| recovery_entry(recovery_dir, key)).collect();
     out.sort_by(|a, b| b.info.saved_at.cmp(&a.info.saved_at).then(a.info.key.cmp(&b.info.key)));
     out
 }
 
+/// `key`'s entry. The sidecar is tried again last: it can appear after the first look, once the
+/// bundle it describes is committed, and is never removed by a save.
+fn recovery_entry(recovery_dir: &Path, key: &str) -> Option<RecoveryEntry> {
+    let bundle = recovery_dir.join(format!("{key}.pcraft"));
+    sidecar_entry(recovery_dir, key, &bundle).or_else(|| sidecarless_entry(recovery_dir, &bundle)).or_else(|| sidecar_entry(recovery_dir, key, &bundle))
+}
+
+fn sidecar_entry(recovery_dir: &Path, key: &str, bundle: &Path) -> Option<RecoveryEntry> {
+    let bytes = read_sidecar_bounded(&recovery_dir.join(format!("{key}.json")), 1 << 20)?;
+    let info = serde_json::from_slice::<RecoveryInfo>(&bytes).ok()?;
+    (sanitize(&info.key) == info.key && info.key == key && bundle.join(crate::store::MANIFEST).is_file())
+        .then(|| RecoveryEntry { info, bundle: bundle.to_path_buf() })
+}
+
 /// A committed `<key>.pcraft` bundle (its manifest is written last) whose sidecar was never
 /// published, e.g. a crash during a document's first autosave. The metadata is rebuilt from the
 /// manifest (read like a load reads it) and its modification time. Incomplete bundles (no
 /// readable manifest) and bundles with anything at the sidecar's path are not entries.
 fn sidecarless_entry(recovery_dir: &Path, bundle: &Path) -> Option<RecoveryEntry> {
     let key = bundle.file_name()?.to_str()?.strip_suffix(".pcraft")?;
-    if key.is_empty() || sanitize(key) != key || std::fs::symlink_metadata(recovery_dir.join(format!("{key}.json"))).is_ok() {
+    if !std::fs::symlink_metadata(bundle).is_ok_and(|m| m.is_dir())
+        || key.is_empty()
+        || sanitize(key) != key
+        || std::fs::symlink_metadata(recovery_dir.join(format!("{key}.json"))).is_ok()
+    {
         return None;
     }
     let meta = std::fs::symlink_metadata(bundle.join(crate::store::MANIFEST)).ok().filter(|m| m.is_file())?;