X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=git-debrebase;h=4f9a9bb98e21bbe6a5e46ddbc3adc262173d7fce;hb=cfbec7a706fd1f631ebbed0c545980590eb26656;hp=5049ca6d5948d94837a28e3d5cdf12b6d445c721;hpb=55b32c7177b49f38528dabff534a743c28339844;p=dgit.git

diff --git a/git-debrebase b/git-debrebase
index 5049ca6d..4f9a9bb9 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -36,6 +36,8 @@ use Dpkg::Version;
 use File::FnMatch qw(:fnmatch);
 use File::Copy;
 
+$debugcmd_when_debuglevel = 2;
+
 our ($usage_message) = <<'END';
 usages:
   git-debrebase [<options>] [--|-i <git rebase options...>]
@@ -226,7 +228,7 @@ sub get_differs ($$) {
 	    unless $differs & (D_PAT_ADD|D_PAT_OTH);
     }
 
-    printdebug sprintf "get_differs %s, %s = %#x\n", $x, $y, $differs;
+    printdebug sprintf "get_differs %s %s = %#x\n", $x, $y, $differs;
 
     return $differs;
 }
@@ -261,11 +263,15 @@ sub read_tree_debian ($) {
     rm_subdir_cached 'debian/patches';
 }
 
-sub read_tree_upstream ($;$) {
-    my ($treeish, $keep_patches) = @_;
-    my $save = cmdoutput @git, qw(write-tree --prefix=debian/);
+sub read_tree_upstream ($;$$) {
+    my ($treeish, $keep_patches, $tree_with_debian) = @_;
+    # if $tree_with_debian is supplied, will use that for debian/
+    # otherwise will save and restore it.
+    my $debian =
+	$tree_with_debian ? "$tree_with_debian:debian"
+	: cmdoutput @git, qw(write-tree --prefix=debian/);
     runcmd @git, qw(read-tree), $treeish;
-    read_tree_subdir 'debian', $save;
+    read_tree_subdir 'debian', $debian;
     rm_subdir_cached 'debian/patches' unless $keep_patches;
 };
 
@@ -342,11 +348,11 @@ sub gbp_pq_export ($$$) {
 }
 
 
-# xxx allow merge separately from laundering
+# xxx allow merge resolution separately from laundering, before git merge
 #
-# xxx docs highlight forbidden things
-# xxx docs list allowable things ?
-# xxx docs explicitly forbid some rebase
+# xxx general gdr docs highlight forbidden things
+# xxx general gdr docs list allowable things ?
+# xxx general gdr docs explicitly forbid some rebase
 #
 # xxx provide a way for the user to help
 # xxx (eg, provide wreckage provide way to continue)
@@ -393,6 +399,7 @@ sub merge_series ($$;@) {
 		my @earlier;
 		while (my $patch = <S>) {
 		    chomp $patch or die $!;
+		    $prereq{$patch} //= {};
 		    foreach my $earlier (@earlier) {
 			$prereq{$patch}{$earlier}{$s}++ and die;
 		    }
@@ -526,6 +533,13 @@ sub merge_series ($$;@) {
 	}
 	$result = $build;
 	runcmd @git, qw(update-ref refs/heads/result), $result;
+
+	runcmd @git, qw(checkout -q -b debug);
+	runcmd @git, qw(commit --allow-empty -q -m M-INDEX);
+	runcmd @git, qw(add .);
+	runcmd @git, qw(commit --allow-empty -q -m M-WORKTREE);
+	printdebug sprintf "merge_series done debug=%s\n",
+	    git_rev_parse 'HEAD';
     };
     printdebug "merge_series returns $result\n";
     return $result;
@@ -807,8 +821,23 @@ sub classify ($) {
     return $classify->("VanillaMerge");
 }
 
-sub keycommits ($;$$$$) {
-    my ($head, $furniture, $unclean, $trouble, $fatal) = @_;
+sub keycommits ($;$$$$$);
+
+sub mergedbreakwaters_anchor ($) {
+    my ($cl) = @_;
+    my $best_anchor;
+    foreach my $p (@{ $cl->{Parents} }) {
+	my ($panchor, $pbw) = keycommits $p->{CommitId},
+	    undef,undef,undef,undef, 1;
+	$best_anchor = $panchor
+	    if !defined $best_anchor
+	    or is_fast_fwd $best_anchor, $panchor;
+    }
+    return $best_anchor;
+}
+
+sub keycommits ($;$$$$$) {
+    my ($head, $furniture, $unclean, $trouble, $fatal, $claimed_bw) = @_;
     # => ($anchor, $breakwater)
 
     # $unclean->("unclean-$tagsfx", $msg, $cl)
@@ -824,6 +853,8 @@ sub keycommits ($;$$$$) {
     # $fatal is for unprocessable commits, and should normally cause
     #    a failure.  If ignored, agaion, (undef, undef) is returned.
     #
+    # If $claimed_bw, this is supposed to be a breakwater commit.
+    #
     # If a callback is undef, fail is called instead.
     # If a callback is defined but false, the situation is ignored.
     # Callbacks may say:
@@ -831,6 +862,7 @@ sub keycommits ($;$$$$) {
     # if the answer is no longer wanted.
 
     my ($anchor, $breakwater);
+    $breakwater = $head if $claimed_bw;
     my $clogonly;
     my $cl;
     my $found_pm;
@@ -843,6 +875,13 @@ sub keycommits ($;$$$$) {
 	return unless $cb;
 	$cb->("unclean-$tagsfx", $why, $cl, $mainwhy);
     };
+    my $found_anchor = sub {
+	($anchor) = @_;
+	$breakwater //= $clogonly;
+	$breakwater //= $head;
+	no warnings qw(exiting);
+	last;
+    };
     for (;;) {
 	$cl = classify $head;
 	my $ty = $cl->{Type};
@@ -856,10 +895,7 @@ sub keycommits ($;$$$$) {
 	} elsif ($ty eq 'Anchor' or
 		 $ty eq 'TreatAsAnchor' or
 		 $ty eq 'BreakwaterStart') {
-	    $anchor = $head;
-	    $breakwater //= $clogonly;
-	    $breakwater //= $head;
-	    last;
+	    $found_anchor->($head);
 	} elsif ($ty eq 'Upstream') {
 	    $x->($unclean, 'ordering',
  "packaging change ($breakwater) follows upstream change"," (eg $head)")
@@ -891,6 +927,8 @@ sub keycommits ($;$$$$) {
 	    $x->($trouble, 'vanillamerge',
 		 "found vanilla merge"," ($head)");
 	    return (undef,undef);
+	} elsif ($ty eq 'MergedBreakwaters') {
+	    $found_anchor->(mergedbreakwaters_anchor $cl);
 	} else {
 	    $x->($fatal, 'unprocessable',
 		 "found unprocessable commit, cannot cope: $cl->{Why}",
@@ -1079,8 +1117,16 @@ sub walk ($;$$$) {
 	    }
 	    die "$ty ?";
 	} elsif ($ty eq 'VanillaMerge' or $ty eq 'MergedBreakwaters') {
-	    # xxx need to handle ffq if one side was unstitched
-	    # wait both of them may be!
+	    # User may have merged unstitched branch(es).  We will
+	    # have now lost what ffq-prev was then (since the later
+	    # pseudomerge may introduce further changes).  The effect
+	    # of resolving such a merge is that we may have to go back
+	    # further in history to find a merge base, since the one
+	    # which was reachable via ffq-prev is no longer findable.
+	    # This is suboptimal, but if it all works we'll have done
+	    # the right thing.
+	    # xxx we should warn the user in the docs about this
+
 	    my $ok=1;
 	    my $best_anchor;
 	    # We expect to find a dominating anchor amongst the
@@ -1204,7 +1250,8 @@ sub walk ($;$$$) {
 	    push @brw_cl, {
                 %$cl,
                 SpecialMethod => 'MergeCreateMergedBreakwaters',
-                $xmsg->('construct merged breakwater from vanilla merge'),
+                $xmsg->('constructed from vanilla merge',
+			' merged-breakwater'),
             };
 	    push @upp_cl, {
                 %$cl,
@@ -1285,7 +1332,16 @@ sub walk ($;$$$) {
 		    $cl->{MergeInterchangeBaseInfo},
 		    @{ $cl->{Parents} };
 		$last_anchor = $cl->{MergeBestAnchor};
-		# xxx need to check the tree somehow
+		my $check_differs = get_differs $build, $cl->{CommitId};
+		# Breakwater changes which were in each side of the
+		# merge should be in MergeCreateMergedBreakwaters
+		# output.  Upstream changes are exactly the result
+		# of merge_series.  So the only difference should
+		# be potential laundry results.
+		$nomerge->(sprintf
+                    "merge misresolved: tree is not the same (%s %s d.%#x)",
+			   $cl->{CommitId}, $build, $check_differs)
+		    if $check_differs & ~D_PAT_ADD;
 		print "Merge resolution successful.\n";
 		next;
 	    } else {