# HG changeset patch
# User Pulkit Goyal <7895pulkit@gmail.com>
# Date 1600392533 25200
# Node ID bddc4f2ef317f14dff9626553ba08d33f3fd6550
# Parent  8ceb5b4b2728181162986c842a4a5ee7983ec285
remotefilelog: acquire lock before writing requirements on clone

Performing a shallow clone in remotefilelog does not acquire lock. This leads to
following warning when we try to write some requirements in store:

```
--- /home/gps/src/hg-committed/tests/test-remotefilelog-share.t
+++ /home/gps/src/hg-committed/tests/test-remotefilelog-share.t#safe.err
@@ -28,6 +28,7 @@


   $ hgcloneshallow ssh://user@dummy/master source --noupdate -q
+  devel-warn: write with no lock: "requires" at: /home/gps/src/hg-committed/mercurial/scmutil.py:1505 (writerequires)
   $ hg share source dest
   updating working directory
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
```

Let's lock before writing the requirements file.

Another solution which I can think of is not warn about missing lock when
writing to requires file in store.

Differential Revision: https://phab.mercurial-scm.org/D8952

diff -r 8ceb5b4b2728 -r bddc4f2ef317 hgext/remotefilelog/__init__.py
--- a/hgext/remotefilelog/__init__.py	Thu Sep 10 14:23:12 2020 +0900
+++ b/hgext/remotefilelog/__init__.py	Thu Sep 17 18:28:53 2020 -0700
@@ -362,7 +362,10 @@
                         self.unfiltered().__class__,
                     )
                 self.requirements.add(constants.SHALLOWREPO_REQUIREMENT)
-                scmutil.writereporequirements(self)
+                with self.lock():
+                    # acquire store lock before writing requirements as some
+                    # requirements might be written to .hg/store/requires
+                    scmutil.writereporequirements(self)
 
                 # Since setupclient hadn't been called, exchange.pull was not
                 # wrapped. So we need to manually invoke our version of it.