[PATCH 2/4] v2writable: initializing an existing inbox is idempotent

["Eric Wong (Contractor, The Linux Foundation)" <e@80x24.org>]

And we do not want to start making confused repos if somebody
leaves out "-V2" the second time around.
---
 lib/PublicInbox/V2Writable.pm |  1 -
 script/public-inbox-init      | 17 ++++++++++++++++-
 t/init.t                      | 32 ++++++++++++++++++++++++++++++--
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index b516278..4e7d6de 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -360,7 +360,6 @@ sub git_init {
 	my ($self, $new) = @_;
 	my $pfx = "$self->{-inbox}->{mainrepo}/git";
 	my $git_dir = "$pfx/$new.git";
-	die "$git_dir exists\n" if -e $git_dir;
 	my @cmd = (qw(git init --bare -q), $git_dir);
 	PublicInbox::Import::run_die(\@cmd);
 
diff --git a/script/public-inbox-init b/script/public-inbox-init
index 86cf8b5..d6a6482 100755
--- a/script/public-inbox-init
+++ b/script/public-inbox-init
@@ -15,7 +15,7 @@ use Cwd qw/abs_path/;
 
 sub x { system(@_) and die join(' ', @_). " failed: $?\n" }
 sub usage { print STDERR "Usage: $usage\n"; exit 1 }
-my $version = 1;
+my $version = undef;
 my %opts = ( 'V|version=i' => \$version );
 GetOptions(%opts) or usage();
 my $name = shift @ARGV or usage();
@@ -71,6 +71,21 @@ my $pfx = "publicinbox.$name";
 my @x = (qw/git config/, "--file=$pi_config_tmp");
 
 $mainrepo = abs_path($mainrepo);
+if (-f "$mainrepo/inbox.lock") {
+	if (!defined $version) {
+		$version = 2;
+	} elsif ($version != 2) {
+		die "$mainrepo is a -V2 repo, -V$version specified\n"
+	}
+} elsif (-d "$mainrepo/objects") {
+	if (!defined $version) {
+		$version = 1;
+	} elsif ($version != 1) {
+		die "$mainrepo is a -V1 repo, -V$version specified\n"
+	}
+}
+
+$version = 1 unless defined $version;
 
 if ($version >= 2) {
 	require PublicInbox::V2Writable;
diff --git a/t/init.t b/t/init.t
index 6ae608e..59f5481 100644
--- a/t/init.t
+++ b/t/init.t
@@ -7,6 +7,23 @@ use PublicInbox::Config;
 use File::Temp qw/tempdir/;
 my $tmpdir = tempdir('pi-init-XXXXXX', TMPDIR => 1, CLEANUP => 1);
 use constant pi_init => 'blib/script/public-inbox-init';
+use PublicInbox::Import;
+use File::Basename;
+open my $null, '>>', '/dev/null';
+my $rdr = { 2 => fileno($null) };
+sub quiet_fail {
+	my ($cmd, $msg) = @_;
+	# run_die doesn't take absolute paths:
+	my $path = $ENV{PATH};
+	if (index($cmd->[0], '/') >= 0) {
+		my ($dir, $base) = ($cmd->[0] =~ m!\A(.+)/([^/]+)\z!);
+		$path = "$dir:$path";
+		$cmd->[0] = $base;
+	}
+	local $ENV{PATH} = $path;
+	eval { PublicInbox::Import::run_die($cmd, undef, $rdr) };
+	isnt($@, '', $msg);
+}
 
 {
 	local $ENV{PI_DIR} = "$tmpdir/.public-inbox/";
@@ -23,6 +40,10 @@ use constant pi_init => 'blib/script/public-inbox-init';
 		   qw(http://example.com/clist clist@example.com));
 	is(system(@cmd), 0, 'public-inbox-init clist OK');
 	is((stat($cfgfile))[2] & 07777, 0666, "permissions preserved");
+
+	@cmd = (pi_init, 'clist', '-V2', "$tmpdir/clist",
+		   qw(http://example.com/clist clist@example.com));
+	quiet_fail(\@cmd, 'attempting to init V2 from V1 fails');
 }
 
 SKIP: {
@@ -38,8 +59,15 @@ SKIP: {
 	ok(-d "$tmpdir/v2list", 'v2list directory exists');
 	ok(-f "$tmpdir/v2list/msgmap.sqlite3", 'msgmap exists');
 	ok(-d "$tmpdir/v2list/all.git", 'catch-all.git directory exists');
-	@cmd = (qw(git config), "--file=$tmpdir/v2list/all.git/config",
-		qw(core.sharedRepository 0644));
+	@cmd = (pi_init, 'v2list', "$tmpdir/v2list",
+		   qw(http://example.com/v2list v2list@example.com));
+	is(system(@cmd), 0, 'public-inbox-init is idempotent');
+	ok(! -d "$tmpdir/public-inbox" && !-d "$tmpdir/objects",
+		'idempotent invocation w/o -V2 does not make inbox v1');
+
+	@cmd = (pi_init, 'v2list', "-V1", "$tmpdir/v2list",
+		   qw(http://example.com/v2list v2list@example.com));
+	quiet_fail(\@cmd, 'initializing V2 as V1 fails');
 }
 
 done_testing();
-- 
EW