X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=blobdiff_plain;f=git-debrebase;h=9d0bda0b41b4cc6ccce0c1f6bd87144bb36dd77d;hp=706af5425130298c9968fa3b298842db0dd6bf4b;hb=625ef9cc461653073175be47c4b6a2a9e25c13d1;hpb=7bc6dfb448ed6279adb7a3eafa3dcc86a2c111b5

diff --git a/git-debrebase b/git-debrebase
index 706af542..9d0bda0b 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -196,6 +196,8 @@ sub get_tree ($;$$) {
 	return () if $type eq 'missing';
     }
 
+    confess "get_tree needs object not $x ?" unless $x =~ m{^[0-9a-f]+\:};
+
     our (@get_tree_memo, %get_tree_memo);
     my $memo = $get_tree_memo{$x};
     return @$memo if $memo;
@@ -426,6 +428,17 @@ sub any_snags () {
     return $snags_forced || $snags_tripped;
 }
 
+sub ffq_prev_branchinfo () {
+    my $current = git_get_symref();
+    return gdr_ffq_prev_branchinfo($current);
+}
+
+sub record_gdrlast ($$;$) {
+    my ($gdrlast, $newvalue, $oldvalue) = @_;
+    $oldvalue ||= $git_null_obj;
+    push @deferred_updates, "update $gdrlast $newvalue $oldvalue";
+}
+
 sub gbp_pq_export ($$$) {
     my ($bname, $base, $tip) = @_;
     # must be run in a workarea.  $bname and patch-queue/$bname
@@ -681,6 +694,8 @@ sub merge_series_patchqueue_convert ($$$) {
 	runcmd @git, qw(checkout -q -b mergec), $merged_pq;
 
 	merge_attempt_cmd($wrecknotes, qw(gbp pq import));
+	# MERGE-TODO consider git-format-patch etc. instead,
+	# since gbp pq doesn't always round-trip :-/
 
 	# OK now we are on patch-queue/merge, and we need to rebase
 	# onto the intended parent and drop the patches from each one
@@ -1731,11 +1746,6 @@ sub cmd_analyse () {
     STDOUT->error and die $!;
 }
 
-sub ffq_prev_branchinfo () {
-    my $current = git_get_symref();
-    return gdr_ffq_prev_branchinfo($current);
-}
-
 sub ffq_check ($;$$) {
     # calls $ff and/or $notff zero or more times
     # then returns either (status,message) where status is
@@ -1877,8 +1887,7 @@ sub stitch ($$$$$) {
 	    # ffq-prev is ahead of us, and the only tree changes it has
 	    # are possibly addition of things in debian/patches/.
 	    # Just wind forwards rather than making a pointless pseudomerge.
-	    push @deferred_updates,
-		"update $gdrlast $ffq_prev_commitish $git_null_obj";
+	    record_gdrlast $gdrlast, $ffq_prev_commitish;
 	    update_head_checkout $old_head, $ffq_prev_commitish,
 		"stitch (fast forward)";
 	    return;
@@ -1891,7 +1900,7 @@ sub stitch ($$$$$) {
 	'Declare fast forward / record previous work',
         "[git-debrebase pseudomerge: $prose]",
     ];
-    push @deferred_updates, "update $gdrlast $new_head $git_null_obj";
+    record_gdrlast $gdrlast, $new_head;
     update_head $old_head, $new_head, "stitch: $prose";
 }
 
@@ -2401,6 +2410,29 @@ sub check_series_has_all_patches ($) {
     }
 }
 
+sub begin_convert_from () {
+    my $head = get_head();
+    my ($ffqs, $ffqm, $symref, $ffq_prev, $gdrlast) = ffq_prev_branchinfo();
+
+    fail "ffq-prev exists, this is already managed by git-debrebase!"
+	if $ffq_prev && git_get_ref $ffq_prev;
+
+    my $gdrlast_obj = $gdrlast && git_get_ref $gdrlast;
+    snag 'already-converted',
+	"ahead of debrebase-last, this is already managed by git-debrebase!"
+	if $gdrlast_obj && is_fast_fwd $gdrlast_obj, $head;
+    return ($head, { LastRef => $gdrlast, LastObj => $gdrlast_obj });
+}
+
+sub complete_convert_from ($$$$) {
+    my ($old_head, $new_head, $gi, $mrest) = @_;
+    ffq_check $new_head;
+    record_gdrlast $gi->{LastRef}, $new_head, $gi->{LastObj}
+	if $gi->{LastRef};
+    snags_maybe_bail();
+    update_head_checkout $old_head, $new_head, $mrest;
+}
+
 sub cmd_convert_from_gbp () {
     badusage "want only 1 optional argument, the upstream git commitish"
 	unless @ARGV<=1;
@@ -2415,7 +2447,7 @@ sub cmd_convert_from_gbp () {
     my $upstream =
 	resolve_upstream_version($upstream_spec, $upstream_version);
 
-    my $old_head = get_head();
+    my ($old_head, $gdrlastinfo) = begin_convert_from();
 
     my $upsdiff = get_differs $upstream, $old_head;
     if ($upsdiff & D_UPS) {
@@ -2529,9 +2561,7 @@ END
 	}
     };
 
-    ffq_check $work;
-    snags_maybe_bail();
-    update_head_checkout $old_head, $work, 'convert-from-gbp';
+    complete_convert_from $old_head, $work, $gdrlastinfo, 'convert-from-gbp';
     print <<END or die $!;
 git-debrebase: converted from patched-unapplied (gbp) branch format, OK
 END
@@ -2591,7 +2621,7 @@ sub cmd_convert_from_dgit_view () {
 			 };
     }
 
-    my $head = get_head();
+    my ($head, $gdrlastinfo) = begin_convert_from();
 
     if (!$always) {
 	my $troubles = 0;
@@ -2747,9 +2777,7 @@ END
 
     printf STDERR "Yes, will base new branch on %s\n", $result->{Source};
 
-    ffq_check $result->{Result};
-    snags_maybe_bail();
-    update_head_checkout $head, $result->{Result},
+    complete_convert_from $head, $result->{Result}, $gdrlastinfo,
 	'convert-from-dgit-view';
 }