From a6392a11f9efc7a2227730b2da0a0a922b2c9dd8 Mon Sep 17 00:00:00 2001
From: Andrew Stein <steinlink@gmail.com>
Date: Fri, 6 Feb 2026 13:42:11 -0500
Subject: [PATCH 1/2] Normalize wheel `RECORD` paths (on Windows)

---
 src/module_writer/wheel_writer.rs |  8 ++++++--
 tests/common/other.rs             | 13 +++++++++++++
 tests/run.rs                      | 11 +++++++++++
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/module_writer/wheel_writer.rs b/src/module_writer/wheel_writer.rs
index c3874f888..541f9a1d5 100644
--- a/src/module_writer/wheel_writer.rs
+++ b/src/module_writer/wheel_writer.rs
@@ -110,11 +110,15 @@ impl WheelWriter {
         self.zip.start_file_from_path(&record_filename, options)?;
 
         for (filename, (hash, len)) in self.record {
-            let filename = filename.to_string_lossy();
+            let filename = filename.to_string_lossy().replace("\\", "/");
             writeln!(self.zip, "{filename},sha256={hash},{len}")?;
         }
         // Write the record for the RECORD file itself
-        writeln!(self.zip, "{},,", record_filename.display())?;
+        writeln!(
+            self.zip,
+            "{},,",
+            record_filename.to_string_lossy().replace("\\", "/")
+        )?;
 
         let file = self.zip.finish()?;
         Ok(file.into_path())
diff --git a/tests/common/other.rs b/tests/common/other.rs
index e67dc0c3a..a293393bb 100644
--- a/tests/common/other.rs
+++ b/tests/common/other.rs
@@ -307,6 +307,19 @@ pub fn check_wheel_mtimes(
     Ok(())
 }
 
+pub fn check_wheel_paths(
+    package: impl AsRef<Path>,
+    record_file: &str,
+    unique_name: &str,
+) -> Result<()> {
+    let mut wheel = build_wheel_files(package, unique_name)?;
+    let mut f = wheel.by_path(record_file)?;
+    let mut s = String::new();
+    f.read_to_string(&mut s)?;
+    assert!(!s.contains("\\"));
+    Ok(())
+}
+
 pub fn check_wheel_files(
     package: impl AsRef<Path>,
     expected_files: Vec<&str>,
diff --git a/tests/run.rs b/tests/run.rs
index 26819c125..0066a181f 100644
--- a/tests/run.rs
+++ b/tests/run.rs
@@ -951,6 +951,17 @@ fn pyo3_mixed_include_exclude_wheel_files() {
     ))
 }
 
+// Tests that paths in the wheel `RECORD` use `/` instead of `\\`. Even
+// (especially, exclusively) on Windows.
+#[test]
+fn pyo3_wheel_record_has_normalized_paths() {
+    handle_result(other::check_wheel_paths(
+        "test-crates/pyo3-mixed-include-exclude",
+        "pyo3_mixed_include_exclude-2.1.3.dist-info/RECORD",
+        "wheel-files-pyo3-mixed-include-exclude",
+    ))
+}
+
 #[test]
 fn workspace_sdist() {
     handle_result(other::test_source_distribution(

From 0312f0558ce6020a55dce9194c65ab1e6a39659b Mon Sep 17 00:00:00 2001
From: messense <messense@icloud.com>
Date: Sat, 7 Feb 2026 19:05:01 +0800
Subject: [PATCH 2/2] Use path-slash

---
 src/module_writer/wheel_writer.rs | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/module_writer/wheel_writer.rs b/src/module_writer/wheel_writer.rs
index 541f9a1d5..f47ee4c24 100644
--- a/src/module_writer/wheel_writer.rs
+++ b/src/module_writer/wheel_writer.rs
@@ -8,6 +8,7 @@ use std::path::PathBuf;
 use anyhow::Context as _;
 use anyhow::Result;
 use fs_err::File;
+use path_slash::PathBufExt as _;
 use tracing::debug;
 use zip::ZipWriter;
 use zip::write::SimpleFileOptions;
@@ -110,15 +111,11 @@ impl WheelWriter {
         self.zip.start_file_from_path(&record_filename, options)?;
 
         for (filename, (hash, len)) in self.record {
-            let filename = filename.to_string_lossy().replace("\\", "/");
+            let filename = filename.to_slash_lossy();
             writeln!(self.zip, "{filename},sha256={hash},{len}")?;
         }
         // Write the record for the RECORD file itself
-        writeln!(
-            self.zip,
-            "{},,",
-            record_filename.to_string_lossy().replace("\\", "/")
-        )?;
+        writeln!(self.zip, "{},,", record_filename.to_slash_lossy())?;
 
         let file = self.zip.finish()?;
         Ok(file.into_path())