git-debrebase: capture breakwater tip

[dgit.git] / git-debrebase

diff --git a/git-debrebase b/git-debrebase
index ddfff481edac844cccb4e99534ac2b52fe84dbfe..fbb97329d549328ef775fc087e528904d462e872 100755 (executable)
--- a/git-debrebase
+++ b/git-debrebase
@@ -22,9 +22,26 @@
 #    git-debrebase launder     # prints breakwater tip
 #    git-debrebase analyse
 #    git-debrebase start       # like ffrebase start + debrebase launder
-#    git-debrebase new-upstream [-f] UPSTREAM[,...]
+#    git-debrebase create-new-upstream [-f] <upstreaminfo>
+#    git-debrebase new-upstream [-f] <upstreaminfo>
 #    git-debrebase <git-rebase options>  # does debrebase start if necessary
 #
+# <upstreaminfo> is
+#    [,][<subdir>:][+]<commitid>[,...]
+#
+# if initial comma is supplied, entries are not positional.  Unspecified
+# <subdir> means root (and there may be only one).
+# xxx want auto branch names
+# xxx too complicated
+# how about for now
+#    [+]<commit> [<subdir:> [+]<commit>...]
+# ?  plus options
+#     --new-upstream-different-subtrees
+
+#    UPSTREAM[,[[SUBDIR:]SUBUPSTREAM]
+#    default for SUBDIR: is from previous upstream merge[xxx terminology]
+#    
+#
 #xxx
 # when starting must record original start (for ff)
 # and new rebase basis
@@ -205,7 +222,7 @@ sub launder ($$$) {
     my ($input, $pseudos_must_overwrite_this, $wantdebonly) = @_;
     # go through commits backwards
     # we generate two lists of commits to apply
-    my (@deb_cl, @ups_cl);
+    my (@deb_cl, @ups_cl, @processed);
     my %found;
     my @pseudomerges;
 
@@ -217,6 +234,9 @@ sub launder ($$$) {
        $ms .= "\n\n[git-debrebase $appendinfo]\n";
        return (Msg => $ms);
     };
+    my $rewrite_from_here = sub {
+       push @processed, { SpecialMethod => 'StartRewrite' };
+    };
 
     my $cur = $input;
 
@@ -228,13 +248,16 @@ sub launder ($$$) {
        my $p0 = $cl->{Parents}[0]{CommitId};
        if ($ty eq 'AddPatches') {
            $cur = $p0;
+           $rewrite_from_here->();
            next;
        } elsif ($ty eq 'Packaging') {
            push @deb_cl, $cl;
+           push @processed, $cl;
            $cur = $p0;
            next;
        } elsif ($ty eq 'Upstream') {
            push @ups_cl, $cl;
+           push @processed, $cl;
            $cur = $p0;
            next;
        } elsif ($ty eq 'Mixed') {
@@ -245,12 +268,14 @@ sub launder ($$$) {
            };
            $queue->(\@deb_cl, "debian");
            $queue->(\@ups_cl, "upstream");
+           $rewrite_from_here->();
            next;
        } elsif ($ty eq 'Pseudomerge') {
            if (defined $pseudos_must_overwrite_this) {
                confess 'xxx actually check this';
            }
            push @pseudomerges, $cl;
+           $rewrite_from_here->();
            $cur = $ty->{Contributor};
            next;
        } elsif ($ty eq 'BreakwaterUpstreamMerge') {
@@ -282,6 +307,7 @@ sub launder ($$$) {
            };
            my $differs = get_differs $previous_breakwater, $cl->{Tree};
            $basis = launder $pseudomerges[0]{Overwritten}, undef, 1;
+           $rewrite_from_here->();
            last;
        } else {
            die "Reached difficult commit $cur: ".Dumper($cl);
@@ -292,6 +318,8 @@ sub launder ($$$) {
     workarea_fresh();
     in_workarea sub { xxx attributes xxx };
 
+    my $rewriting = 1;
+
     my $build = $basis;
 
     my $rm_tree_cached = sub {
@@ -313,9 +341,10 @@ sub launder ($$$) {
 
     in_workarea sub {
        mkdir $rd or $!==EEXIST or die $!;
-
        my $current_method;
-       foreach my $cl (qw(Debian), @deb_cl, qw(Upstream), @ups_cl) {
+       foreach my $cl (qw(Debian), (reverse @deb_cl),
+                       { SpecialMethod => 'RecordBreakwaterTip' },
+                       qw(Upstream), (reverse @ups_cl)) {
            if (!ref $cl) {
                $current_method = $cl;
                next;
@@ -327,6 +356,13 @@ sub launder ($$$) {
                $read_tree_debian->($cltree);
            } elsif ($method eq 'Upstream') {
                $read_tree_upstream->($cltree);
+           } elsif ($method eq 'StartRewrite') {
+               $rewriting = 1;
+               next;
+           } elsif ($method eq 'RecordBreakwaterTip') {
+               last if $wantdebonly;
+               $breakwater = $build;
+               next;
            } elsif ($method eq 'DgitImportDebianUpdate') {
                $read_tree_debian->($cltree);
                $rm_tree_cached(qw(debian/patches));
@@ -336,14 +372,27 @@ sub launder ($$$) {
            } else {
                confess "$method ?";
            }
+           $rewriting ||= $cl ne pop @processed;
            my $newtree = cmdoutput @git, qw(write-tree);
-           my $ch = $cl->{Msg};
+           my $ch = $cl->{Hdr};
            $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
-           $ch =~ s{^committer .*$}{$committer_authline}m or confess "$ch ?";
-           open CD, ">", "$rd/m" or die $!;
+           $ch =~ s{^parent .*\n}{}m;
+           $ch =~ s{(?=^author}{
+               map { "parent $_\n" } @parents
+           }me or confess "$ch ?";
+           if ($rewrite) {
+               $ch =~ s{^committer .*$}{$committer_authline}m
+                   or confess "$ch ?";
+           }
+           my $cf = "$rd/m$rewrite"
+               open CD, ">", $cf or die $!;
            print CD $ch, "\n", $cl->{Msg}; or die $!;
            close CD or die $!;
-           my $newcommit = cmdoutput @git, qw(hash-object -t commit), "$rd/m";
+           my @cmd = (@git, qw(hash-object));
+           push @cmd, qw(-w) if $rewrite;
+           push @cmd, qw(-t commit), $cf;
+           my $newcommit = cmdoutput @cmd;
+           confess "$ch ?" unless $rewrite or $newcommit eq $cl->{CommitId};
            $build = $newcommit;
        }
     };
@@ -352,7 +401,7 @@ sub launder ($$$) {
        map { $wantdebonly ? "$_:debian" : $_ },
        $input, $build;
 
-    return $build;
+    return ($build, $breakwater);
 }
 
 sub get_head () { return git_rev_parse qw(HEAD); }
@@ -364,8 +413,9 @@ sub update_head ($$) {
 
 sub cmd_launder () {
     my $old = get_head();
-    my $got = launder $old, 0, undef, 0;
-    update_head $old, $new, 'launder'; # no tree changes!
+    my ($tip,$breakwater) = launder $old, 0, undef, 0;
+    update_head $old, $tip, 'launder'; # no tree changes!
+    printf "# breakwater tip:\n%s\n", $breakwater;
 }
 
 my $toplevel = runcmd @git, qw(rev-parse --show-toplevel);