# HG changeset patch
# User Pulkit Goyal <7895pulkit@gmail.com>
# Date 2020-09-08 14:06:40
# Node ID 64de86fd0984ff1e2306de52849be7ebf7dcfd25
# Parent  5523e3e1bc717ac155dcd68803dd861fe62414f6

tags: take lock instead of wlock before writing hgtagsfnodes1 cache

This cache is shared across stores and hence we should take store lock before
writing to it. Otherwise there will be race where one share with wlock is
writing to this cache and other share with wlock is trying to read it
simultaneously.

Differential Revision: https://phab.mercurial-scm.org/D9001

diff --git a/mercurial/tags.py b/mercurial/tags.py
--- a/mercurial/tags.py
+++ b/mercurial/tags.py
@@ -838,7 +838,7 @@ class hgtagsfnodescache(object):
         repo = self._repo
 
         try:
-            lock = repo.wlock(wait=False)
+            lock = repo.lock(wait=False)
         except error.LockError:
             repo.ui.log(
                 b'tagscache',
diff --git a/tests/test-tags.t b/tests/test-tags.t
--- a/tests/test-tags.t
+++ b/tests/test-tags.t
@@ -156,7 +156,7 @@ Tag cache debug info written to blackbox
 Failure to acquire lock results in no write
 
   $ rm -f .hg/cache/tags2-visible .hg/cache/hgtagsfnodes1
-  $ echo 'foo:1' > .hg/wlock
+  $ echo 'foo:1' > .hg/store/lock
   $ hg identify
   b9154636be93 tip
   $ hg blackbox -l 6
@@ -170,7 +170,7 @@ Failure to acquire lock results in no wr
   $ fnodescacheexists
   no fnodes cache
 
-  $ rm .hg/wlock
+  $ rm .hg/store/lock
 
   $ rm -f .hg/cache/tags2-visible .hg/cache/hgtagsfnodes1
   $ hg identify