dgit-badcommit-fixup: Instructions comment

[dgit.git] / dgit-badcommit-fixup

diff --git a/dgit-badcommit-fixup b/dgit-badcommit-fixup
index cd62e6820f9155f29d299aa4b3a2b5cd266857c1..d1bca74dc23f245e2d4b88dec1455df1400bbb55 100755 (executable)
--- a/dgit-badcommit-fixup
+++ b/dgit-badcommit-fixup
@@ -6,6 +6,19 @@
 #   dgit-badcommit-fixup --test
 #   dgit-badcommit-fixup --real
 
+# Update procedure, from server operator's point of view:
+#
+# 1. Test in an offline tree that this DTRT
+#
+# 2. Announce a transition time.  Tell everyone that between
+#    the transition time and their next upload, they must
+#    run this script.
+#
+# 3. At the transition time, run this script in every repo.
+#
+# 4. Run the mirror script to push changes, if necessary.
+
+
 use strict;
 
 use POSIX;
@@ -97,8 +110,10 @@ sub rewrite_commit ($) {
     if ($newdata eq $olddata) {
        $newobj = $obj;
        $count{unchanged}++;
+#print STDERR "UNCHANGED $obj\n";
     } else {
        $newobj = hashobj $newdata, 'commit';
+#print STDERR "REWRITTEN $obj $newobj\n";
     }
     $$m= $newobj;
     return $newobj;
@@ -129,9 +144,12 @@ sub rewrite_tag ($) {
     return hashobj $_, 'tag';
 }
 
-sub rewrite_rewrite_map ($) {
+sub edit_rewrite_map ($) {
     my ($old) = @_;
 
+    filter_updates();
+    return $old unless @updates;
+
     my $td = 'dgit-broken-fixup.tmp';
     runcmd qw(rm -rf), $td;
     mkdir $td, 0700 or die "$td $!";
@@ -155,18 +173,26 @@ sub rewrite_rewrite_map ($) {
        close M or die $!;
     }
 
-    filter_updates();
-    foreach my $up (@updates) {
-       $map{ $_->[1] } = $_->[2];
+    foreach my $oldc (keys %memo) {
+       my $newc = $memo{$oldc};
+       next if $oldc eq $newc;
+       $map{$oldc} = $newc;
+    }
+    foreach my $up (@updates) { # catches tags
+       $map{ $up->[1] } = $up->[2];
     }
 
     open M, ">", "map" or die $!;
-    print M "%s%s\n",
+    printf M "%s%s\n",
        $_, (defined $map{$_} ? " $map{$_}" : "")
-       or die $!;
+       or die $!
        foreach keys %map;
     close M or die $!;
 
+    if (!$old) {
+       runcmd qw(git add map);
+    }
+
     runcmd qw(git commit -q), 
        qw(-m), 'dgit-badcommit-fixup',
        qw(map);
@@ -196,7 +222,7 @@ foreach my $rline (split /\n/, $refs) {
     my ($obj, $type, $refname) = 
        $rline =~ m/^(\w+)\s+(\w+)\s+(\S.*)/
        or die "$_ ?";
-    if ($refname eq 'refs/dgit-rewrite-map') {
+    if ($refname eq 'refs/dgit-rewrite/map') {
        $org_rewrite_map = $obj;
        continue;
     }
@@ -214,29 +240,32 @@ foreach my $rline (split /\n/, $refs) {
 
 if ($bare eq 'true') {
     my $new_rewrite_map = edit_rewrite_map($org_rewrite_map);
-    push @updates, [ 'refs/dgit-rewrite-map',
+    push @updates, [ 'refs/dgit-rewrite/map',
                     ($org_rewrite_map // '0'x40),
-                    $new_rewrite_map ];
+                    ($new_rewrite_map // '0'x40),
+                    1 ];
 }
 
 filter_updates();
 
+if (!@updates) {
+    print Dumper(\%count), "nothing to do\n";
+    exit 0;
+}
+
 #print Dumper(\@updates);
 
 open U, "|git update-ref -m 'dgit bad commit fixup' --stdin" or die $!;
 
-if ($real && $bare eq 'false') {
-    print "detaching your HEAD\n" or die $!;
-    runcmd 'git checkout --detach';
-}
-
 for my $up (@updates) {
-    my ($ref, $old, $new) = @$up;
+    my ($ref, $old, $new, $nobackup) = @$up;
     my $otherref = $ref;
     $otherref =~ s{^refs/}{};
     if ($real) {
-       print U <<END or die $!;
+       print U <<END or die $! unless $nobackup;
 create refs/dgit-badcommit/$otherref $old
+END
+       print U <<END or die $!;
 update $ref $new $old
 END
     } else {