X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=blobdiff_plain;f=git-debrebase;h=5fabfd6762e7a3d407521cafe17047ad5bb242e0;hp=8fa5adb73b34f29054f4bd043551e3143f1a724a;hb=542f874e8973e59e1dc3c2aa87584e05b8d1bbad;hpb=d806e898308acbaca5685a4dec6688c0164ea642

diff --git a/git-debrebase b/git-debrebase
index 8fa5adb7..5fabfd67 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -50,11 +50,9 @@ usages:
 See git-debrebase(1), git-debrebase(5), dgit-maint-debrebase(7) (in dgit).
 END
 
-our ($opt_force, $opt_careful, $opt_noop_ok, @opt_anchors);
+our ($opt_force, $opt_noop_ok, $opt_merges, @opt_anchors);
 our ($opt_defaultcmd_interactive);
 
-$opt_careful = 0;
-
 our $us = qw(git-debrebase);
 
 our $wrecknoteprefix = 'refs/debrebase/wreckage';
@@ -183,19 +181,34 @@ sub run_deferred_updates ($) {
     @deferred_update_messages = ();
 }
 
-sub get_tree ($) {
+sub get_tree ($;$$) {
     # tree object name => ([ $name, $info ], ...)
     # where $name is the sort key, ie has / at end for subtrees
     # $info is the LHS from git-ls-tree (<mode> <type> <hash>)
-    # will crash if $x does not exist, so don't do that
-    my ($x) = @_;
+    # without $precheck, will crash if $x does not exist, so don't do that;
+    # instead pass '' to get ().
+    my ($x, $precheck, $recurse) = @_;
+
+    return () if !length $x;
+
+    if ($precheck) {
+	my ($type, $dummy) = git_cat_file $x, [qw(tree missing)];
+	return () if $type eq 'missing';
+    }
+
+    $recurse = !!$recurse;
+
+    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};
+    my $memo = $get_tree_memo{$recurse,$x};
     return @$memo if $memo;
 
     local $Debian::Dgit::debugcmd_when_debuglevel = 3;
     my @l;
-    my @cmd = (qw(git ls-tree -z --full-tree --), $x);
+    my @cmd = (qw(git ls-tree -z --full-tree));
+    push @cmd, qw(-r) if $recurse;
+    push @cmd, qw(--), $x;
     my $o = cmdoutput @cmd;
     $o =~ s/\0$//s;
     my $last = '';
@@ -205,7 +218,7 @@ sub get_tree ($) {
 	push @l, [ $n, $i ];
 	confess "$x need $last < $n ?" unless $last lt $n;
     }
-    $get_tree_memo{$x} = \@l;
+    $get_tree_memo{$recurse,$x} = \@l;
     push @get_tree_memo, $x;
     if (@get_tree_memo > 10) {
 	delete $get_tree_memo{ shift @get_tree_memo };
@@ -214,15 +227,18 @@ sub get_tree ($) {
 }
 
 sub trees_diff_walk ($$$;$) {
-    # trees_diff_walk [$all,] $x, $y, sub {... }
-    # calls sub->($name, $ix, $iy) for each difference (with $all, each name)
+    # trees_diff_walk [{..opts...},] $x, $y, sub {... }
+    # calls sub->($name, $ix, $iy) for each difference
     # $x and $y are as for get_tree
     # where $name, $ix, $iy are $name and $info from get_tree
-    my $all = shift @_ if @_>=4;
+    # opts are   all       call even for names same in both
+    #            recurse   call even for names same in both
+    my $opts = shift @_ if @_>=4;
     my ($x,$y,$call) = @_;
+    my $all = $opts->{all};
     return if !$all and $x eq $y;
-    my @x = get_tree $x;
-    my @y = get_tree $y;
+    my @x = get_tree $x, 0, $opts->{recurse};
+    my @y = get_tree $y, 0, $opts->{recurse};
     printdebug "trees_diff_walk(..$x,$y..) ".Dumper(\@x,\@y)
 	if $debuglevel >= 3;
     while (@x || @y) {
@@ -245,70 +261,78 @@ sub trees_diff_walk ($$$;$) {
 
 sub get_differs ($$) {
     my ($x,$y) = @_;
-    # This resembles quiltify_trees_differ, in dgit, a bit.
+    # This does a similar job to quiltify_trees_differ, in dgit, a bit.
     # But we don't care about modes, or dpkg-source-unrepresentable
     # changes, and we don't need the plethora of different modes.
     # Conversely we need to distinguish different kinds of changes to
     # debian/ and debian/patches/.
+    # Also, here we have, and want to use, trees_diff_walk, because
+    # we may be calling this an awful lot and we want it to be fast.
 
     my $differs = 0;
+    my @debian_info;
 
-    my $rundiff = sub {
-	my ($opts, $limits, $fn) = @_;
-	my @cmd = (@git, qw(diff-tree -z --no-renames));
-	push @cmd, @$opts;
-	push @cmd, "$_:" foreach $x, $y;
-	push @cmd, '--', @$limits;
-	my $diffs = cmdoutput @cmd;
-	foreach (split /\0/, $diffs) { $fn->(); }
-    };
+    no warnings qw(exiting);
 
-    $rundiff->([qw(--name-only)], [], sub {
-        $differs |= $_ eq 'debian' ? DS_DEB : D_UPS;
-    });
+    my $plain = sub { $_[0] =~ m{^(100|0*)644 blob }s; };
 
-    if ($differs & DS_DEB) {
-	$differs &= ~DS_DEB;
-	$rundiff->([qw(--name-only -r)], [qw(debian)], sub {
-            $differs |=
-		m{^debian/patches/}      ? D_PAT_OTH  :
-		$_ eq 'debian/changelog' ? D_DEB_CLOG :
-		                           D_DEB_OTH;
-	});
-	die "mysterious debian changes $x..$y"
-	    unless $differs & (D_PAT_OTH|DS_DEB);
-    }
-
-    if ($differs & D_PAT_OTH) {
-	my $mode;
-	$differs &= ~D_PAT_OTH;
-	my $pat_oth = sub {
-	    $differs |= D_PAT_OTH;
-	    no warnings qw(exiting);  last;
-	};
-	$rundiff->([qw(--name-status -r)], [qw(debian/patches/)], sub {
-            no warnings qw(exiting);
-            if (!defined $mode) {
-		$mode = $_;  next;
+    trees_diff_walk "$x:", "$y:", sub {
+	my ($n,$ix,$iy) = @_;
+
+	# analyse difference at the toplevel
+
+	if ($n ne 'debian/') {
+	    $differs |= D_UPS;
+	    next;
+	}
+	if ($n eq 'debian') {
+	    # one side has a non-tree for ./debian !
+	    $differs |= D_DEB_OTH;
+	    next;
+	}
+
+	my $xd = $ix && "$x:debian";
+	my $yd = $iy && "$y:debian";
+	trees_diff_walk $xd, $yd, sub {
+	    my ($n,$ix,$iy) = @_;
+	    
+	    # analyse difference in debian/
+
+	    if ($n eq 'changelog' && (!$ix || $plain->($ix))
+                                  &&          $plain->($iy) ) {
+		$differs |= D_DEB_CLOG;
+		next;
 	    }
-	    die unless s{^debian/patches/}{};
-	    my $ok;
-	    if ($mode eq 'A' && !m/\.series$/s) {
-		$ok = 1;
-	    } elsif ($mode eq 'M' && $_ eq 'series') {
-		my $x_s = (git_cat_file "$x:debian/patches/series", 'blob');
-		my $y_s = (git_cat_file "$y:debian/patches/series", 'blob');
-		chomp $x_s;  $x_s .= "\n";
-		$ok = $x_s eq substr($y_s, 0, length $x_s);
-	    } else {
-		# nope
+	    if ($n ne 'patches/') {
+		$differs |= D_DEB_OTH;
+		next;
 	    }
-	    $mode = undef;
-	    $differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
-        });
-	die "mysterious debian/patches changes $x..$y"
-	    unless $differs & (D_PAT_ADD|D_PAT_OTH);
-    }
+
+	    my $xp = $ix && "$xd/patches";
+	    my $yp = $iy && "$yd/patches";
+	    trees_diff_walk { recurse=>1 }, $xp, $yp, sub {
+		my ($n,$ix,$iy) = @_;
+
+		# analyse difference in debian/patches
+
+		my $ok;
+		if ($n =~ m{/$}s) {
+		    # we are recursing; directories may appear and disappear
+		    $ok = 1;
+		} elsif ($n !~ m/\.series$/s && !$ix && $plain->($iy)) {
+		    $ok = 1;
+		} elsif ($n eq 'series' && $plain->($ix) && $plain->($iy)) {
+		    my $x_s = (git_cat_file "$xp/series", 'blob');
+		    my $y_s = (git_cat_file "$yp/series", 'blob');
+		    chomp $x_s;  $x_s .= "\n";
+		    $ok = $x_s eq substr($y_s, 0, length $x_s);
+		} else {
+		    # nope
+		}
+		$differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
+	    };    
+	};
+    };
 
     printdebug sprintf "get_differs %s %s = %#x\n", $x, $y, $differs;
 
@@ -412,6 +436,59 @@ 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 ($$;$) {
+    my ($gdrlast, $newvalue, $oldvalue) = @_;
+    $oldvalue ||= $git_null_obj;
+    push @deferred_updates, "update $gdrlast $newvalue $oldvalue";
+}
+
+sub fail_unprocessable ($) {
+    my ($msg) = @_;
+    changedir $maindir;
+    my ($ffqs, $ffqm, $symref, $ffq_prev, $gdrlast) = ffq_prev_branchinfo();
+
+    my $mangled = <<END;
+Branch/history seems mangled - no longer in gdr format.
+See ILLEGAL OPERATIONS in git-debrebase(5).
+END
+    chomp $mangled;
+
+    if (defined $ffqm) {
+	fail <<END;
+$msg
+Is this meant to be a gdr branch?  $ffqm
+END
+    } elsif (git_get_ref $ffq_prev) {
+	fail <<END;
+$msg
+$mangled
+Consider git-debrebase scrap, to throw away your recent work.
+END
+    } elsif (!git_get_ref $gdrlast) {
+	fail <<END;
+$msg
+Branch does not seem to be meant to be a git-debrebase branch?
+Wrong branch, or maybe you needed git-debrebase convert-from-*.
+END
+    } elsif (is_fast_fwd $gdrlast, git_rev_parse 'HEAD') {
+	fail <<END;
+$msg
+$mangled
+END
+    } else {
+	fail <<END;
+$msg
+Branch/history mangled, and diverged since last git-debrebase.
+Maybe you reset to, or rebased from, somewhere inappropriate.
+END
+    }
+};
+
 sub gbp_pq_export ($$$) {
     my ($bname, $base, $tip) = @_;
     # must be run in a workarea.  $bname and patch-queue/$bname
@@ -430,11 +507,7 @@ sub gbp_pq_export ($$$) {
 }
 
 
-# xxx allow merge resolution separately from laundering, before git merge
-#
-# xxx general gdr docs highlight forbidden things
-# xxx general gdr docs list allowable things ?
-# xxx general gdr docs explicitly forbid some rebase
+# MERGE-TODO allow merge resolution separately from laundering, before git merge
 
 # later/rework?
 #  use git-format-patch?
@@ -671,6 +744,8 @@ 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
@@ -966,7 +1041,6 @@ sub classify ($) {
 
     if (@p == 2 and
 	$r->{Msg} =~ m{^\[git-debrebase merged-breakwater.*\]$}m) {
-	# xxx ^ metadata tag needs adding to (5)
 	return $classify->("MergedBreakwaters");
     }
     if ($r->{Msg} =~ m{^\[(git-debrebase|dgit)[: ].*\]$}m) {
@@ -976,7 +1050,7 @@ sub classify ($) {
 	return $unknown->("octopus merge");
     }
 
-    if (!$ENV{GIT_DEBREBASE_EXPERIMENTAL_MERGE}) {
+    if (!$opt_merges) {
 	return $unknown->("general two-parent merge");
     }
 
@@ -1030,7 +1104,7 @@ sub keycommits ($;$$$$$) {
     my $clogonly;
     my $cl;
     my $found_pm;
-    $fatal //= sub { fail $_[1]; };
+    $fatal //= sub { fail_unprocessable $_[1]; };
     my $x = sub {
 	my ($cb, $tagsfx, $mainwhy, $xwhy) = @_;
 	my $why = $mainwhy.$xwhy;
@@ -1155,7 +1229,7 @@ sub walk ($;$$$) {
 	if ($nogenerate) {
 	    return (undef,undef);
 	}
-	fail "found unprocessable commit, cannot cope".
+	fail_unprocessable "found unprocessable commit, cannot cope".
 	    (defined $cl->{Why} ? "; $cl->{Why}:": ':').
 	    " (commit $cur) (d.".
 	    (join ' ', map { sprintf "%#x", $_->{Differs} }
@@ -1297,7 +1371,7 @@ sub walk ($;$$$) {
 	    # 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
+	    # MERGE-TODO we should warn the user in the docs about this
 
 	    my $ok=1;
 	    my $best_anchor;
@@ -1589,7 +1663,7 @@ sub walk ($;$$$) {
 		    printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
 		}
 	    }
-	    if ($rewriting || $opt_careful) {
+	    if ($rewriting) {
 		read_tree_upstream $want_upstream, 0, $want_debian;
 
 		my $newtree = cmdoutput @git, qw(write-tree);
@@ -1663,7 +1737,7 @@ sub update_head_checkout ($$$) {
 
 sub update_head_postlaunder ($$$) {
     my ($old, $tip, $reflogmsg) = @_;
-    return if $tip eq $old;
+    return if $tip eq $old && !@deferred_updates;
     print "git-debrebase: laundered (head was $old)\n";
     update_head $old, $tip, $reflogmsg;
     # no tree changes except debian/patches
@@ -1722,11 +1796,6 @@ 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 ($;$$) {
     # calls $ff and/or $notff zero or more times
     # then returns either (status,message) where status is
@@ -1868,8 +1937,7 @@ sub stitch ($$$$$) {
 	    # ffq-prev is ahead of us, and the only tree changes it has
 	    # are possibly addition of things in debian/patches/.
 	    # Just wind forwards rather than making a pointless pseudomerge.
-	    push @deferred_updates,
-		"update $gdrlast $ffq_prev_commitish $git_null_obj";
+	    record_gdrlast $gdrlast, $ffq_prev_commitish;
 	    update_head_checkout $old_head, $ffq_prev_commitish,
 		"stitch (fast forward)";
 	    return;
@@ -1882,7 +1950,7 @@ sub stitch ($$$$$) {
 	'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";
 }
 
@@ -2266,7 +2334,10 @@ sub cmd_stitch () {
     badusage "no arguments allowed" if @ARGV;
     do_stitch $prose, 0;
 }
-sub cmd_prepush () { cmd_stitch(); }
+sub cmd_prepush () {
+    $opt_noop_ok = 1;
+    cmd_stitch();
+}
 
 sub cmd_quick () {
     badusage "no arguments allowed" if @ARGV;
@@ -2371,6 +2442,54 @@ sub cmd_make_patches () {
     }
 }
 
+sub check_series_has_all_patches ($) {
+    my ($head) = @_;
+    my $seriesfn = 'debian/patches/series';
+    my ($dummy, $series) = git_cat_file "$head:$seriesfn",
+	[qw(blob missing)];
+    $series //= '';
+    my %series;
+    our $comments_snagged;
+    foreach my $f (grep /\S/, grep {!m/^\s\#/} split /\n/, $series) {
+	if ($f =~ m/^\s*\#/) {
+	    snag 'series-comments',
+		"$seriesfn contains comments, which will be discarded"
+		unless $comments_snagged++;
+	    next;
+	}
+	fail "patch $f repeated in $seriesfn !" if $series{$f}++;
+    }
+    foreach my $patchfile (get_tree "$head:debian/patches", 1,1) {
+	my ($f,$i) = @$patchfile;
+	next if $series{$f};
+	next if $f eq 'series';
+	snag 'unused-patches', "Unused patch file $f will be discarded";
+    }
+}
+
+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;
@@ -2385,7 +2504,7 @@ 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) {
@@ -2418,6 +2537,8 @@ END
 	    "upstream ($upstream) contains debian/ directory";
     }
 
+    check_series_has_all_patches $old_head;
+
     my $previous_dgit_view = eval {
 	my @clogcmd = qw(dpkg-parsechangelog --format rfc822 -n2);
 	my ($lvsn, $suite);
@@ -2438,19 +2559,25 @@ END
 	my $mtag = cmdoutput @git, qw(describe --always --abbrev=0 --match),
 	    $mtag_pat;
 	die "could not find suitable maintainer view tag $mtag_pat\n"
-	    unless $mtag_pat =~ m{/};
+	    unless $mtag =~ m{/};
 	is_fast_fwd $mtag, 'HEAD' or
 	    die "HEAD is not FF from maintainer tag $mtag!";
 	my $dtag = "archive/$mtag";
+	git_get_ref "refs/tags/$dtag" or
+	    die "dgit view tag $dtag not found\n";
 	is_fast_fwd $mtag, $dtag or
-	    die "dgit view tag $dtag is not FF from maintainer tag $mtag";
+	    die "dgit view tag $dtag is not FF from maintainer tag $mtag\n";
 	print "will stitch in dgit view, $dtag\n";
 	git_rev_parse $dtag;
     };
     if (!$previous_dgit_view) {
 	$@ =~ s/^\n+//;
 	chomp $@;
-	print STDERR "cannot stitch in dgit view: $@\n";
+	print STDERR <<END;
+Cannot confirm dgit view: $@
+Failed to stitch in dgit view (see messages above).
+dgit --overwrite will be needed on the first dgit push after conversion.
+END
     }
 
     snags_maybe_bail_early();
@@ -2491,9 +2618,10 @@ 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
 }
 
 sub cmd_convert_to_gbp () {
@@ -2550,7 +2678,7 @@ sub cmd_convert_from_dgit_view () {
 			 };
     }
 
-    my $head = get_head();
+    my ($head, $gdrlastinfo) = begin_convert_from();
 
     if (!$always) {
 	my $troubles = 0;
@@ -2568,6 +2696,8 @@ END
 	}
     }
 
+    check_series_has_all_patches $head;
+
     snags_maybe_bail_early();
 
     my $version = upstreamversion $clogp->{Version};
@@ -2704,15 +2834,13 @@ 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';
 }
 
 sub cmd_record_resolved_merge () {
     badusage "record-resolved-merge takes no further arguments" if @ARGV;
-    # xxx needs documentation
+    # MERGE-TODO needs documentation
     my $new = get_head();
     my $method;
 
@@ -2807,6 +2935,7 @@ getoptions_main
 	   'anchor=s' => \@opt_anchors,
 	   '--dgit=s' => \($dgit[0]),
 	   'force!',
+	   'experimental-merge-resolution!', \$opt_merges,
 	   '-i:s' => sub {
 	       my ($opt,$val) = @_;
 	       badusage "git-debrebase: no cuddling to -i for git-rebase"