test_line_count = 2 new # There is one new pack and its .idx
'
+run_and_wait_for_auto_gc () {
+ # We read stdout from gc for the side effect of waiting until the
+ # background gc process exits, closing its fd 9. Furthermore, the
+ # variable assignment from a command substitution preserves the
+ # exit status of the main gc process.
+ # Note: this fd trickery doesn't work on Windows, but there is no
+ # need to, because on Win the auto gc always runs in the foreground.
+ doesnt_matter=$(git gc --auto 9>&1)
+}
+
+test_expect_success 'background auto gc does not run if gc.log is present and recent but does if it is old' '
+ test_commit foo &&
+ test_commit bar &&
+ git repack &&
+ test_config gc.autopacklimit 1 &&
+ test_config gc.autodetach true &&
+ echo fleem >.git/gc.log &&
+ test_must_fail git gc --auto 2>err &&
+ test_i18ngrep "^error:" err &&
+ test_config gc.logexpiry 5.days &&
+ test-chmtime =-345600 .git/gc.log &&
+ test_must_fail git gc --auto &&
+ test_config gc.logexpiry 2.days &&
+ run_and_wait_for_auto_gc &&
+ ls .git/objects/pack/pack-*.pack >packs &&
+ test_line_count = 1 packs
+'
+
+test_expect_success 'background auto gc respects lock for all operations' '
+ # make sure we run a background auto-gc
+ test_commit make-pack &&
+ git repack &&
+ test_config gc.autopacklimit 1 &&
+ test_config gc.autodetach true &&
+
+ # create a ref whose loose presence we can use to detect a pack-refs run
+ git update-ref refs/heads/should-be-loose HEAD &&
+ test_path_is_file .git/refs/heads/should-be-loose &&
+
+ # now fake a concurrent gc that holds the lock; we can use our
+ # shell pid so that it looks valid.
+ hostname=$(hostname || echo unknown) &&
+ printf "$$ %s" "$hostname" >.git/gc.pid &&
+
+ # our gc should exit zero without doing anything
+ run_and_wait_for_auto_gc &&
+ test_path_is_file .git/refs/heads/should-be-loose
+'
+
+# DO NOT leave a detached auto gc process running near the end of the
+# test script: it can run long enough in the background to racily
+# interfere with the cleanup in 'test_done'.
test_done