git-debrebase: WIP

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

1 files changed, 217 insertions, 29 deletions

diff --git a/git-debrebase b/git-debrebase
index bb2d91a..0fb7c3c 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -19,9 +19,11 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 use strict;
+
 use Memoize;
+use Data::Dumper;
 
-use Debian::Dgit;
+use Debian::Dgit qw(:DEFAULT $wa);
 
 sub cfg ($) {
     my ($k) = @_;
@@ -51,6 +53,22 @@ sub D_UPS ()     { return 0x2; }
 sub D_PAT_ADD () { return 0x4; }
 sub D_PAT_OTH () { return 0x8; }
 
+our $rd = ".git/git-debrebase";
+our $ud = "$rd/work";
+
+sub commit_pr_info ($) {
+    my ($r) = @_;
+    return Data::Dumper->dump([$r], [qw(commit)]);
+}
+
+sub calculate_committer_authline () {
+    my $c = cmdoutput @git, qw(commit-tree --no-gpg-sign -m),
+	'XXX DUMMY COMMIT (git-debrebase)', "$basis:";
+    my ($h,$m) = get_commit $c;
+    $h =~ m/^committer .*$/m or confess "($h) ?";
+    return $&;
+}
+
 sub classify ($) {
     my ($objid) = @_;
 
@@ -64,6 +82,7 @@ sub classify ($) {
 	CommitId => $objid,
 	Hdr => $hdr,
 	Msg => $m,
+        Tree => $t,
 	Parents => \@p,
     };
 
@@ -75,6 +94,17 @@ sub classify ($) {
         };
     }
 
+    my $classify = sub {
+	my ($type, @rest) = @_;
+	$r = { %r, Type => $type, @rest };
+	return $r;
+    };
+    my $unknown = sub {
+	my ($why) = @_;
+	$r = { %r, Type => Unknown };
+	return $r;
+    }
+
     if (@p == 1) {
 	my $d = $r->{Parents}[0]{Differs};
 	if ($d == D_DPAT_ADD) {
@@ -112,26 +142,34 @@ sub classify ($) {
 	    $1;
 	} @p;
 	return $classify->(qw(Pseudomerge),
-			   Xtype => qw(Ambiguous),
+			   SubType => qw(Ambiguous),
 			   Overwritten => $bytime[0],
-			   Contributyor => $bytime[1]);
-    }
+			   Contributor => $bytime[1]);
+    }!
     foreach my $p (@p) {
-	my ($type) = git_cat_file "$p^1";
-	$p->{IsOrigin} = $type eq 'missing';
+	my ($p_h, $p_m) = get_commit $p;
+	$p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
+	($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
     }
-    if (!grep { !$_->{IsOrigin} } @p
-	&& $m =~ m{^\[dgit import unpatched .*\]$}m) {
-	return $classify->(qw(DgitImport));
+    my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' };
+    my $m2 = $m;
+    if (!(grep { !$_->{IsOrigin} } @p) and
+	(@origs >= @p - 1) and
+	$m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
+	$r->{NewMsg} = $m2;
+	return $classify->(qw(DgitImportUnpatched),
+			   OrigParents => \@orig_ps);
     }
 
     my ($stype, $series) = git_cat_file "$t:debian/patches/series";
     my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
 
-    # how to decide about l/r ordering of breakwater merges
-    # git --topo-order prefers to expand 2nd parent first
-    # easy rune to look for debian/ history so that should
-    # be 1st parent.
+    # How to decide about l/r ordering of breakwater merges ?  git
+    # --topo-order prefers to expand 2nd parent first.  There's
+    # already an easy rune to look for debian/ history anyway (git log
+    # debian/) so debian breakwater branch should be 1st parent; that
+    # way also there's also an easy rune to look for the upstream
+    # patches (--topo-order).
     if (@p == 2 &&
 	!$haspatches &&
 	!$p[0]{IsOrigin} && # breakwater merge never starts with an origin
@@ -144,6 +182,172 @@ sub classify ($) {
     return $unknown->("complex merge");
 }
 
+sub launder ($;$) {
+    my ($cur, $wantdebonly) = @_;
+    # go through commits backwards
+    # we generate two lists of commits to apply
+    my (@deb_cl, @ups_cl);
+    my %found;
+    my @pseudomerges;
+
+    my $cl;
+    my $xmsg = sub {
+	my ($appendinfo) = @_;
+	my $ms = $cl->{Msg};
+	chomp $ms;
+	$ms .= "\n\n[git-debrebase $appendinfo]\n";
+	return (Msg => $ms);
+    };
+
+    for (;;) {
+	$cl = classify $cur;
+	my $ty = $cl->{Type};
+	my $st = $cl->{SubType};
+	$found{$ty. ( defined($st) ? "-$st" : '' )}++;
+	my $p0 = $cl->{Parents}[0]{CommitId};
+	if ($ty eq 'AddPatches') {
+	    $cur = $p0;
+	    next;
+	} elsif ($ty eq 'Packaging') {
+	    push @deb_cl, $cl;
+	    $cur = $p0;
+	    next;
+	} elsif ($ty eq 'Upstream') {
+	    push @ups_cl, $cl;
+	    $cur = $p0;
+	    next;
+	} elsif ($ty eq 'Mixed') {
+	    my $queue = sub {
+		my ($q, $wh) = @_;
+		my $cls = { $cl, $xmsg->("split mixed commit: $wh part") };
+		push @$q, $cls;
+	    };
+	    $queue->(\@deb_cl, "debian");
+	    $queue->(\@ups_cl, "upstream");
+	    next;
+	} elsif ($ty eq 'Pseudomerge') {
+	    push @pseudomerges, $cl;
+	    $cur = $ty->{Contributor};
+	    next;
+	} elsif ($ty eq 'BreakwaterUpstreamMerge') {
+	    $basis = $cur;
+	    last;
+	} elsif ($ty eq 'DgitImportUnpatched' &&
+		 @pseudomerges == 1) {
+	    # This import has a tree which is just like a breakwater
+	    # tree, but it has the wrong history.  Its ought to have
+	    # the previous breakwater (which dgit ought to have
+	    # generated a pseudomerge to overwrite) as an ancestor.
+	    # That will make the history of the debian/ files correct.
+	    # As for the upstream version: either it's the same upstream
+	    # as the previous breakwater, in which case that history is
+	    # precisely right.  Otherwise, it was a non-gitish upload
+	    # of a new upstream version.  We can tell these apart
+	    # by looking at the tree of the supposed upstream.
+	    if ($differs & D_UPS) {
+		push @deb_cl, {
+                    %r,
+                    SpecialMethod => 'DgitImportUpstreamUpdate',
+                    $xmsg->("convert dgit import: debian changes")
+                };
+	    }
+	    push @deb_cl, {
+		%r,
+		SpecialMethod => 'DgitImportDebianUpdate',
+                $xmsg->("convert dgit import: upstream changes")
+	    };
+	    my $differs = get_differs $previous_breakwater, $cl->{Tree};
+	    $basis = launder $pseudomerges[0]{Overwritten}, 1;
+	    last;
+	} else {
+	    die "Reached difficult commit $cur: ".Dumper($cl);
+	}
+    }
+    # Now we build it back up again
+
+    workarea_fresh();
+    in_workarea sub { xxx attributes xxx };
+
+    my $build = $basis;
+
+    my $rm_tree_cached = sub {
+	my ($subdir) = @_;
+	runcmd @git, qw(rm --quiet -rf --cached), $subdir;
+    };
+    my $read_tree_debian = sub {
+	my ($treeish) = @_;
+	$rm_tree_cached->(qw(debian));
+	runcmd @git, qw(read-tree --prefix=debian/), "$treeish:debian";
+    };
+    my $read_tree_upstream = sub {
+	my ($treeish) = @_;
+	runcmd @git, qw(read-tree), $treeish;
+	$read_tree_debian->($build);
+    };
+ 
+    my $committer_authline = calculate_committer_authline();
+
+    in_workarea sub {
+	my $current_method;
+	foreach my $cl (qw(Debian), @deb_cl, qw(Upstream), @ups_cl) {
+	    if (!ref $cl) {
+		$current_method = $cl;
+		next;
+	    }
+	    $method = $cl->{SpecialMethod} // $current_method;
+	    my @parents = ($build);
+	    my $cltree = $cl->{CommitId}
+	    if ($method eq 'Debian') {
+		$read_tree_debian->($cltree);
+	    } elsif ($method eq 'Upstream') {
+		$read_tree_upstream->($cltree);
+	    } elsif ($method eq 'DgitImportDebianUpdate') {
+		$read_tree_debian->($cltree);
+		$rm_tree_cached(qw(debian/patches));
+	    } elsif ($method eq 'DgitImportUpstreamUpdate') {
+		$read_tree_upstream->($cltree);
+		push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
+	    } else {
+		confess "$method ?";
+	    }
+	    my $newtree = cmdoutput @git, qw(write-tree);
+	    my $ch = $cl->{Msg};
+	    $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
+	    $ch =~ s{^committer .*$}{$committer_authline}m or confess "$ch ?";
+	    my $newcommit = cmdoutput @git, qw(hash-object -t commit),
+		$ch."\n".$cl->{Msg};
+	    
+
+	    #my $cdata = <<END;
+tree $newtree
+author $
+    };
+
+		$r->{FixupUpstreamMerge} = $
+
+		push @deb_cl, {
+                    $cl,
+                    Type => NonGitNewUpstreamDgitImport,
+                    PreviousBreakwaterMerge => 
+		
+
+	    push @phases, [ @deb_cl, @ups_cl ];
+	    
+	    if (@pseudomerges != 1) {
+}   
+
+
+chdir $GIT_DIR
+
+			       
+if ($ARGV[0] eq 'launder') {
+    launder();
+}
+
+use Data::Dumper;
+print Dumper(cfg('wombat.foo.bar'));
+
+
 	((git_cat_file "$t:debian/patches/series"
 	
     
@@ -167,22 +371,6 @@ sub classify ($) {
     
 		    
 
-sub launder () {
-    # go through commits backwards
-    # we generate two lists of commits to apply
-    my (@deb_cl, @ups_cl);
-    my $cur = git_rev_parse('HEAD');
-    for (;;) {
-}   
-
-if ($ARGV[0] eq 'launder') {
-    launder();
-}
-
-use Data::Dumper;
-print Dumper(cfg('wombat.foo.bar'));
-
-