config: reject `\n' in `inboxdir'

"\n" and other characters requiring quoting and/or escaping in
in $GIT_DIR/objects/info/alternates was not supported in git 2.11
and earlier; nor does it seem supported at all in libgit2.

This will allow us to support sharing git-cat-file or similar
endpoints across multiple inboxes via alternates.

This breaks an existing use case for anybody wacky
enough to put `\n' in the `inboxdir' pathname; but I doubt
this affects anybody.

1 files changed, 13 insertions, 3 deletions

diff --git a/t/config.t b/t/config.t
index ad543ad3..d7fd9446 100644
--- a/t/config.t
+++ b/t/config.t
@@ -10,13 +10,23 @@ my ($tmpdir, $for_destroy) = tmpdir();
 
 {
         PublicInbox::Import::init_bare($tmpdir);
-        my @cmd = ('git', "--git-dir=$tmpdir", qw(config foo.bar), "hi\nhi");
+        my $inboxdir = "$tmpdir/new\nline";
+        my @cmd = ('git', "--git-dir=$tmpdir",
+                qw(config publicinbox.foo.inboxdir), $inboxdir);
         is(xsys(@cmd), 0, "set config");
 
         my $tmp = PublicInbox::Config->new("$tmpdir/config");
 
-        is("hi\nhi", $tmp->{"foo.bar"}, "config read correctly");
-        is("true", $tmp->{"core.bare"}, "used --bare repo");
+        is($tmp->{'publicinbox.foo.inboxdir'}, $inboxdir,
+                'config read correctly');
+        is($tmp->{'core.bare'}, 'true', 'init used --bare repo');
+
+        my @warn;
+        local $SIG{__WARN__} = sub { push @warn, @_ };
+        $tmp = PublicInbox::Config->new("$tmpdir/config");
+        is($tmp->lookup_name('foo'), undef, 'reject invalid inboxdir');
+        like("@warn", qr/^E:.*must not contain `\\n'/sm,
+                'warned about newline');
 }
 
 {