From 4826fff7346f831d5bd7d17ef3218ac3dd7e1012 Mon Sep 17 00:00:00 2001
From: dotCooCoo <RobertLeeLW@gmail.com>
Date: Mon, 26 Oct 2026 11:34:06 -0700
Subject: [PATCH] Originals: a Windows file index of 0 does not identify a file

same_file::is_same_file treats two files with the same volume serial
number and file index as one file, also when both report index 0. The
Windows comparison now reads both identities through winapi-util and
accepts a match only when both file indexes are nonzero; otherwise the
resolved paths are compared, as for a volume without file indexes.
---
 Cargo.lock                      |  2 +-
 Cargo.toml                      |  2 +-
 crates/catalog/Cargo.toml       |  2 +-
 crates/catalog/src/safe_file.rs | 33 +++++++++++++++++++++++++++++----
 4 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 3e9acf98c..0fcf8a35c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3221,11 +3221,11 @@ dependencies = [
  "lightcraft-testkit",
  "log",
  "proptest",
- "same-file",
  "serde",
  "serde_json",
  "thiserror 2.0.21",
  "web-time",
+ "winapi-util",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index fc2d90d2e..4e122eb24 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -53,7 +53,7 @@ log = "0.4"
 # All date/time conversion goes through chrono (no hand-rolled calendar code beyond the 400-year range extension; AGENTS.md).
 chrono = { version = "0.4.45", default-features = false, features = ["std"] }
 rayon = "1"
-same-file = "1" # lightcraft-catalog reads a file's volume serial number and file index with it on Windows
+winapi-util = "0.1" # lightcraft-catalog reads a file's volume serial number and file index with it on Windows
 proptest = "1"
 bytemuck = { version = "1", features = ["derive"] }
 crc32fast = "1"
diff --git a/crates/catalog/Cargo.toml b/crates/catalog/Cargo.toml
index 7a9c80439..b12e18803 100644
--- a/crates/catalog/Cargo.toml
+++ b/crates/catalog/Cargo.toml
@@ -21,7 +21,7 @@ chrono = { workspace = true }
 web-time = { workspace = true }
 
 [target.'cfg(windows)'.dependencies]
-same-file = { workspace = true }
+winapi-util = { workspace = true }
 
 [dev-dependencies]
 lightcraft-geom = { workspace = true }
diff --git a/crates/catalog/src/safe_file.rs b/crates/catalog/src/safe_file.rs
index 9b8bf5bcd..bc05d4139 100644
--- a/crates/catalog/src/safe_file.rs
+++ b/crates/catalog/src/safe_file.rs
@@ -301,13 +301,13 @@ fn compare_files(a: &Path, b: &Path, strict: bool) -> io::Result<bool> {
             return Ok(false);
         }
         // A hard link has its own path but shares the volume serial number and file index with
-        // its original. A volume that does not report them is compared by resolved path below.
+        // its original. A volume that reports file index 0 is compared by resolved path below.
         // On ReFS two files can share the 64-bit file index, so the lengths are compared first.
         #[cfg(windows)]
         {
-            match ::same_file::is_same_file(a, b) {
-                Ok(true) => return Ok(true),
-                Ok(false) => {}
+            match file_ids(a, b) {
+                Ok((ia, ib)) if same_file_id(ia, ib) => return Ok(true),
+                Ok(_) => {}
                 Err(e) if strict => return Err(e),
                 Err(_) => {}
             }
@@ -319,6 +319,22 @@ fn compare_files(a: &Path, b: &Path, strict: bool) -> io::Result<bool> {
     }
 }
 
+/// The volume serial number and file index of `a` and `b`, read while both files are open.
+#[cfg(windows)]
+fn file_ids(a: &Path, b: &Path) -> io::Result<((u64, u64), (u64, u64))> {
+    use winapi_util::{Handle, file::information};
+    let (ha, hb) = (Handle::from_path_any(a)?, Handle::from_path_any(b)?);
+    let (ia, ib) = (information(&ha)?, information(&hb)?);
+    Ok(((ia.volume_serial_number(), ia.file_index()), (ib.volume_serial_number(), ib.file_index())))
+}
+
+/// Whether two (volume serial number, file index) pairs name one file. A file index of 0 is not
+/// an identity and matches nothing.
+#[cfg(any(windows, test))]
+fn same_file_id(a: (u64, u64), b: (u64, u64)) -> bool {
+    a.1 != 0 && b.1 != 0 && a == b
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -480,4 +496,13 @@ mod tests {
         assert!(!same_file_strict(&p.join("under-a-file.jpg"), &p).unwrap());
         let _ = fs::remove_dir_all(&d);
     }
+
+    #[test]
+    fn a_zero_file_index_is_not_a_file_identity() {
+        assert!(same_file_id((7, 42), (7, 42)));
+        assert!(!same_file_id((7, 42), (7, 43)));
+        assert!(!same_file_id((7, 42), (8, 42)));
+        assert!(!same_file_id((7, 0), (7, 0)), "two files on a volume that reports index 0 are not the same file");
+        assert!(!same_file_id((0, 0), (0, 0)));
+    }
 }