Merge branch 'hy/read-cache-lock-error-fix'

A failure to open the index file for writing due to conflicting
access did not state what went wrong, which has been corrected.

* hy/read-cache-lock-error-fix:
  read-cache: report lock error when refreshing index

Author: gitster

read-cache.c

@@ -1456,7 +1456,8 @@ int repo_refresh_and_write_index(struct repository *repo,
 	struct lock_file lock_file = LOCK_INIT;
 	int fd, ret = 0;
 
-	fd = repo_hold_locked_index(repo, &lock_file, 0);
+	fd = repo_hold_locked_index(repo, &lock_file,
+				    gentle ? 0 : LOCK_REPORT_ON_ERROR);
 	if (!gentle && fd < 0)
 		return -1;
 	if (refresh_index(repo->index, refresh_flags, pathspec, seen, header_msg))

t/t3903-stash.sh

@@ -1672,11 +1672,9 @@ test_expect_success 'stash create reports a locked index' '
 		echo change >A.file &&
 		touch .git/index.lock &&
 
-		cat >expect <<-EOF &&
-		error: could not write index
-		EOF
 		test_must_fail git stash create 2>err &&
-		test_cmp expect err
+		test_grep "error: could not write index" err &&
+		test_grep "error: Unable to create '.*index.lock'" err
 	)
 '
 
@@ -1689,11 +1687,9 @@ test_expect_success 'stash push reports a locked index' '
 		echo change >A.file &&
 		touch .git/index.lock &&
 
-		cat >expect <<-EOF &&
-		error: could not write index
-		EOF
 		test_must_fail git stash push 2>err &&
-		test_cmp expect err
+		test_grep "error: could not write index" err &&
+		test_grep "error: Unable to create '.*index.lock'" err
 	)
 '
 
@@ -1707,11 +1703,9 @@ test_expect_success 'stash apply reports a locked index' '
 		git stash push &&
 		touch .git/index.lock &&
 
-		cat >expect <<-EOF &&
-		error: could not write index
-		EOF
 		test_must_fail git stash apply 2>err &&
-		test_cmp expect err
+		test_grep "error: could not write index" err &&
+		test_grep "error: Unable to create '.*index.lock'" err
 	)
 '