fetch: ignore non-writable epoch dirs

This will eventually be useful for maintaing partial mirrors.

Keeping inline with the original public-inbox-fetch philosophy,
there are no additional config files to manage:
the user merely needs to remove write permissions to an $N.git
directory to prevent it from being updated.

Re-enabling updates just requires restoring write permission.

1 files changed, 29 insertions, 1 deletions

diff --git a/t/v2mirror.t b/t/v2mirror.t
index 3df5d053..665a4d59 100644
--- a/t/v2mirror.t
+++ b/t/v2mirror.t
@@ -3,7 +3,7 @@
 use strict;
 use v5.10.1;
 use PublicInbox::TestCommon;
-use File::Path qw(remove_tree);
+use File::Path qw(remove_tree make_path);
 use Cwd qw(abs_path);
 require_git(2.6);
 require_cmd('curl');
@@ -235,6 +235,34 @@ for my $d (@new_epochs) {
                 'include.path set');
 }
 
+if ('test read-only epoch dirs') {
+        my @git = ('git', "--git-dir=$new_epochs[0]");
+        my $get_objs = [@git,
+                qw(cat-file --buffer --batch-check --batch-all-objects)];
+        my $before = [sort xqx($get_objs)];
+
+        remove_tree(map { "$new_epochs[0]/$_" } qw(objects refs/heads));
+        chmod(0555, $new_epochs[0]) or xbail "chmod: $!";
+
+        # force a refetch
+        unlink("$tmpdir/m/manifest.js.gz") or xbail "unlink: $!";
+
+        run_script([qw(-fetch -q)], undef, {-C => "$tmpdir/m"}) or
+                xbail '-fetch failed';
+
+        ok(!-d "$new_epochs[0]/objects", 'no objects after fetch to R/O dir');
+
+        chmod(0755, $new_epochs[0]) or xbail "chmod: $!";
+        mkdir("$new_epochs[0]/objects") or xbail "mkdir: $!";
+        mkdir("$new_epochs[0]/refs/heads") or xbail "mkdir: $!";
+
+        my $err = '';
+        run_script([qw(-fetch -q)], undef, {-C => "$tmpdir/m", 2 => \$err}) or
+                xbail '-fetch failed '.$err;
+        is_deeply([ sort xqx($get_objs) ], $before,
+                'fetch restored objects once GIT_DIR became writable');
+}
+
 ok($td->kill, 'killed httpd');
 $td->join;