From fcf066aff5eb44802865b532a1163b495916304a Mon Sep 17 00:00:00 2001
From: Smit Barmase <heysmitbarmase@gmail.com>
Date: Thu, 8 May 2025 03:12:32 -0700
Subject: [PATCH] fs: Fall back from atomic write to regular fs write when file
 handle is in use on Windows (#30222)

Closes #30054

For reference, another way to work around this is to drop the file
handle which we can't do in this case, as it would require reopening the
settings.json worktree, which is a rather unpleasant fix.

Another approach might be to open the file handle with some special
flags, but I couldn't get that to work at the time of writing.

Release Notes:

- Fixed "Backup and Update" in settings migration not working on
Windows.
---
 crates/fs/src/fs.rs | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/crates/fs/src/fs.rs b/crates/fs/src/fs.rs
index 93cd1eb593977d73060e26655ac69f1ac2b5115e..d1c59a2b58c9026fd5722ea41035daeab565820b 100644
--- a/crates/fs/src/fs.rs
+++ b/crates/fs/src/fs.rs
@@ -546,7 +546,24 @@ impl Fs for RealFs {
                 NamedTempFile::new()
             }?;
             tmp_file.write_all(data.as_bytes())?;
-            tmp_file.persist(path)?;
+
+            let result = tmp_file.persist(&path);
+            if cfg!(target_os = "windows") {
+                // If file handle is already in used we receive error:
+                //
+                // failed to persist temporary file:
+                // Access is denied. (os error 5)
+                //
+                // So we use direct fs write instead to avoid it.
+                // https://github.com/zed-industries/zed/issues/30054
+                if let Err(persist_err) = &result {
+                    if persist_err.error.raw_os_error() == Some(5) {
+                        return std::fs::write(&path, data.as_bytes()).map_err(Into::into);
+                    }
+                }
+            }
+            result?;
+
             Ok::<(), anyhow::Error>(())
         })
         .await?;