# Script helping make fast-forwarding histories while still rebasing
# upstream deltas when working on Debian packaging
#
-# Copyright (C)2017 Ian Jackson
+# Copyright (C)2017,2018 Ian Jackson
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
-# git-debrebase new-upstreams-v0 \
-# NEW-VERSION ORIG-COMMITISH
-# [EXTRA-ORIG-NAME EXTRA-ORIG-COMMITISH ...]
# usages:
-# git-debrebase status
-# git-debrebase start # like ffqrebase start + debrebase launder
-# git-debrebase new-upstream [stuff] # see below
-# git-debrebase <git-rebase options> # does debrebase start if necessary
#
-# git-debrebase analyse
-# git-debrebase launder # prints breakwater tip
-# git-debrebase create-new-upstream-breakwater [-f] <upstreaminfo>...
+# git-debrebase [<options>] new-upstream-v0 \
+# <new-version> <orig-commitish> \
+# [<extra-orig-name> <extra-orig-commitish> ...] \
+# [<git-rebase options>...]
#
-# <upstreaminfo> is
-# [,][<subdir>:][+]<commitid>[,...]
+# git-debrebase [<options> --] [<git-rebase options...>]
+# git-debrebase [<options>] analyse
+# git-debrebase [<options>] launder # prints breakwater tip etc.
+# git-debrebase [<options>] downstream-rebase-launder-v0 # experimental
#
-# 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
+# git-debrebase [<options>] gbp2debrebase-v0 \
+# <upstream>
+
+# problems / outstanding questions:
+#
+# * dgit push with a `3.0 (quilt)' package means doing quilt
+# fixup. Usually this involves recommitting the whole patch
+# series, one at a time, with dpkg-source --commit. This is
+# terribly terribly slow. (Maybe this should be fixed in dgit.)
+#
+# * dgit push usually needs to (re)make a pseudomerge. The "first"
+# git-debrebase stripped out the previous pseudomerge and could
+# have remembeed the HEAD. But it's not quite clear what history
+# ought to be preserved and what should be discarded. For now
+# the user will have to tell dgit --overwrite.
+#
+# To fix this, do we need a new push hook for dgit ?
+#
+# * Workflow is currently clumsy. Lots of spurious runes to type.
+# There's not even a guide.
+#
+# * There are no tests.
+#
+# * new-upstream-v0 has a terrible UI. You end up with giant
+# runic command lines.
#
-# automatic case
-# git-debrebase new-upstream
-# - previous breakwater merge must be gdr-generated
-# - orig set is the same as before
-# - implicitly uses upstream branches according to orig set
-# - not all upstream branches need be updated
-# - insists on fast-forward of each branch, unless
-# --force (or --force=<subdir>[/])
-# branch set adjustments
-# git-debrebase new-upstream --add <subdir>/
-# git-debrebase new-upstream --rm <subdir>/
-# git-debrebase new-upstream / [<subdir>/ ...]
-# - orig set is adjusted
-# - otherwise like auto (--add is not checked for ffness, obv)
-# - multiple --add and --rm may be specified
-# - --add makes new upstream the last contributor
-# explicit
-# git-debrebase / [<rootcommitid>] [<subdir>/ [<commitid>] ...]
-# - orig set is precisely as specified now
-# - previous breakwater merge is irrelevant
-# - no fast forward checks
-# for now only explicit with commitids
-
-# implicitly uses `upstream'
-# # (or multiple other branches)
-# git-debrebase new-upstream \
-# [<subdir>/]=<commitid>
-
-# UPSTREAM[,[[SUBDIR:]SUBUPSTREAM]
-# default for SUBDIR: is from previous upstream merge[xxx terminology]
-#
+# One consequence of the lack of richness it can need --force in
+# fairly sensible situations and there is no way to tell it what
+# you are really trying to do, other than just --force. There
+# should be an interface with some default branch names.
#
-#xxx
-# when starting must record original start (for ff)
-# and new rebase basis
+# * There should be a standard convention for the version number,
+# and unfinalised or not changelog, after new-upstream.
#
-# git-ffqrebase start [BASE]
-# # records previous HEAD so it can be overwritten
-# # records base for future git-ffqrebase
-# git-ffqrebase set-base BASE
-# git-ffqrebase <git-rebase options>
-# git-ffqrebase finish
-# git-ffqrebase status [BRANCH]
+# * Handing of multi-orig dgit new-upstream .dsc imports is known to
+# be broken. They may be not recognised, improperly converted, or
+# their conversion may be unrecognised.
#
-# refs/ffqrebase-prev/BRANCH BRANCH may be refs/...; if not it means
-# refs/ffqrebase-base/BRANCH refs/heads/BRANCH
-# zero, one, or both of these may exist
+# * Docs need writing and updating. Even README.git-debrebase
+# describes a design but may not reflect the implementation.
#
-# git-debrebase without start, if already started, is willing
-# to strip pseudomerges provided that they overwrite exactly
-# the previous HEAD
-# xxxx is this right ? what matters is have we pushed
-# I think in fact the right answer is:
-# git-debrebase always strips out pseudomerges from its branch
-# a pseudomerge is put in at the time we want to push
-# at that time, we make a pseudomerge of the remote tracking
-# branch (if raw git) or the dgit view (if dgit)
-# for raw git git-ffqrebase, do want preciseley to record
-# value of remote tracking branch or our branch, on start, so we
-# overwrite only things we intend to
-# the previous pseudomerge check for tags and remote branches ?
+# * We need to develop a plausible model that works for derivatives,
+# who probably want to maintain their stack on top of Debian's.
+# downstream-rebase-launder-v0 may be a starting point?
use strict;
use POSIX;
use Data::Dumper;
use Getopt::Long qw(:config posix_default gnu_compat bundling);
+use Dpkg::Version;
our ($opt_force);
memoize('cfg');
+sub dd ($) {
+ my ($v) = @_;
+ my $dd = new Data::Dumper [ $v ];
+ Terse $dd 1; Indent $dd 0; Useqq $dd 1;
+ return Dump $dd;
+}
+
sub get_commit ($) {
my ($objid) = @_;
- my $data = git_cat_file $objid, 'commit';
+ my $data = (git_cat_file $objid, 'commit');
$data =~ m/(?<=\n)\n/ or die "$objid ($data) ?";
return ($`,$');
}
if ($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';
+ 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 {
sub read_tree_subdir ($$) {
my ($subdir, $new_tree_object) = @_;
rm_subdir_cached $subdir;
- runcmd @git, qw(read-tree), "--prefix=$subdir/";
+ runcmd @git, qw(read-tree), "--prefix=$subdir/", $new_tree_object;
+}
+
+sub make_commit ($$) {
+ my ($parents, $message_paras) = @_;
+ my $tree = cmdoutput @git, qw(write-tree);
+ my @cmd = (@git, qw(commit-tree), $tree);
+ push @cmd, qw(-p), $_ foreach @$parents;
+ push @cmd, qw(-m), $_ foreach @$message_paras;
+ return cmdoutput @cmd;
+}
+
+our $fproblems;
+sub fproblem ($) {
+ my ($msg) = @_;
+ $fproblems++;
+ print STDERR "git-debrebase: safety catch tripped: $msg\n";
+}
+sub fproblems_maybe_bail () {
+ if ($fproblems) {
+ if ($opt_force) {
+ printf STDERR
+ "safety catch trips (%d) overriden by --force\n",
+ $fproblems;
+ } else {
+ fail sprintf
+ "safety catch trips (%d) (you could --force)",
+ $fproblems;
+ }
+ }
}
# classify returns an info hash like this
foreach my $ph (@ph) {
push @$p_ref, {
- Ix => $#$p_ref,
+ Ix => scalar @$p_ref,
CommitId => $ph,
};
}
my $t = $r->{Tree};
foreach my $p (@p) {
- $p->{Differs} => (get_differs $p->{CommitId}, $t),
+ $p->{Differs} = (get_differs $p->{CommitId}, $t),
}
printdebug "classify $objid \$t=$t \@p",
my ($type, @rest) = @_;
$r = { %$r, Type => $type, @rest };
if ($debuglevel) {
- my $dd = new Data::Dumper [ $r ];
- Terse $dd 1; Indent $dd 0; Useqq $dd 1;
- printdebug " = $type ".(Dump $dd)."\n";
+ printdebug " = $type ".(dd $r)."\n";
}
return $r;
};
} elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
return $unknown->("edits debian/patches");
} elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
- my ($ty,$dummy) = git_cat_file "$ph[0]:debian";
+ my ($ty,$dummy) = git_cat_file "$p[0]{CommitId}:debian";
if ($ty eq 'tree') {
if ($d == D_DEB_CLOG) {
return $classify->(qw(Changelog));
if (@p == 2 &&
!$haspatches &&
!$p[$prevbrw]{IsOrigin} && # breakwater never starts with an origin
- !($p[$prevbrw]{Differs} & ~DS_DEB) &&
- !($p[!$prevbrw]{Differs} & ~D_UPS)) {
+ !($p[!$prevbrw]{Differs} & ~DS_DEB) && # no non-debian changess
+ !($p[$prevbrw]{Differs} & ~D_UPS)) { # no non-upstream changes
return $classify->(qw(BreakwaterUpstreamMerge),
OrigParents => [ $p[!$prevbrw] ]);
}
sub walk ($;$$) {
my ($input,
$nogenerate,$report) = @_;
- # => ($tip, $breakwater_tip)
+ # => ($tip, $breakwater_tip, $last_upstream_merge_in_breakwater)
# (or nothing, if $nogenerate)
+ printdebug "*** WALK $input ".($nogenerate//0)." ".($report//'-')."\n";
+
# go through commits backwards
# we generate two lists of commits to apply:
# breakwater branch and upstream patches
no warnings qw(exiting); last;
};
+ my $last_upstream_update;
+
for (;;) {
$cl = classify $cur;
my $ty = $cl->{Type};
$cur = $p0;
next;
} elsif ($ty eq 'BreakwaterStart') {
+ $last_upstream_update = $cur;
$build_start->('FirstPackaging', $cur);
} elsif ($ty eq 'Upstream') {
push @upp_cl, $cl;
$cur = $contrib;
next;
} elsif ($ty eq 'BreakwaterUpstreamMerge') {
+ $last_upstream_update = $cur;
$build_start->("PreviousBreakwater", $cur);
} elsif ($ty eq 'DgitImportUnpatched') {
my $pm = $pseudomerges[-1];
printf $report " PM=%s \@Overwr:%d", $pm, (scalar @$ovwrs)
if $report;
if (@$ovwrs != 1) {
+ printdebug "*** WALK BOMB DgitImportUnpatched\n";
return $bomb->();
}
my $ovwr = $ovwrs->[0]{CommitId};
$prline->(" Import");
$rewrite_from_here->();
$upp_limit //= $#upp_cl; # further, deeper, patches discarded
+ die 'BUG $upp_limit is not used anywhere?';
$cur = $ovwr;
next;
} else {
}
die "$ty ?";
} else {
+ printdebug "*** WALK BOMB unrecognised\n";
return $bomb->();
}
}
$prprdelim->();
+
+ printdebug "*** WALK prep done cur=$cur".
+ " brw $#brw_cl upp $#upp_cl proc $#processed pm $#pseudomerges\n";
+
return if $nogenerate;
# Now we build it back up again
my $read_tree_debian = sub {
my ($treeish) = @_;
read_tree_subdir 'debian', "$treeish:debian";
+ rm_subdir_cached 'debian/patches';
};
my $read_tree_upstream = sub {
my ($treeish) = @_;
my $newcommit = cmdoutput @cmd;
confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
$build = $newcommit;
+ if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
+ $last_upstream_update = $cur;
+ }
}
};
die sprintf "internal error %#x %s %s", $final_check, $build, $input
if $final_check & ~D_PAT_ADD;
- return ($build, $breakwater);
+ my @r = ($build, $breakwater, $last_upstream_update);
+ printdebug "*** WALK RETURN @r\n";
+ return @r
}
sub get_head () { return git_rev_parse qw(HEAD); }
update_head $old, $new, $mrest;
}
+sub update_head_postlaunder ($$$) {
+ my ($old, $tip, $reflogmsg) = @_;
+ return if $tip eq $old;
+ print "git-debrebase: laundered (head was $old)\n";
+ update_head $old, $tip, $reflogmsg;
+ # no tree changes except debian/patches
+ runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
+}
+
sub cmd_launder () {
badusage "no arguments to launder allowed" if @ARGV;
my $old = get_head();
- my ($tip,$breakwater) = walk $old;
- update_head $old, $tip, 'launder';
- # no tree changes except debian/patches
- runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
+ my ($tip,$breakwater,$last_upstream_merge) = walk $old;
+ update_head_postlaunder $old, $tip, 'launder';
printf "# breakwater tip\n%s\n", $breakwater;
printf "# working tip\n%s\n", $tip;
+ printf "# last upstream merge\n%s\n", $last_upstream_merge;
+}
+
+sub defaultcmd_rebase () {
+ my $old = get_head();
+ my ($tip,$breakwater) = walk $old;
+ update_head_postlaunder $old, $tip, 'launder for rebase';
+ @ARGV = qw(-i) unless @ARGV; # make configurable
+ runcmd @git, qw(rebase), @ARGV, $breakwater;
}
sub cmd_analyse () {
}
sub cmd_new_upstream_v0 () {
- # xxx would like to support more git-rebase options
- badusage
- "need NEW-VERSION UPS-COMMITISH [EXTRA-UPS-NAME EXTRA-UPS-COMMITISH...]"
- unless @ARGV % 2 == 0 and @ARGV >= 2;
# tree should be clean and this is not checked
# automatically and unconditionally launders before rebasing
# if rebase --abort is used, laundering has still been done
my %pieces;
+ badusage "need NEW-VERSION UPS-COMMITTISH" unless @ARGV >= 2;
+
# parse args - low commitment
- my $new_version = (new Dpkg::Version scalar(shift @ARGV), 1);
+ my $new_version = (new Dpkg::Version scalar(shift @ARGV), check => 1);
my $new_upstream_version = $new_version->version();
my $new_upstream = git_rev_parse shift @ARGV;
my ($n, @x) = @_; # may be ''
my $pc = $pieces{$n} //= {
Name => $n,
- Desc => ($n ? "upstream piece $n" : "upstream (main piece"),
+ Desc => ($n ? "upstream piece \`$n'" : "upstream (main piece"),
};
while (my $k = shift @x) { $pc->{$k} = shift @x; }
+ $pc;
};
my @newpieces;
my $newpiece = sub {
my ($n, @x) = @_; # may be ''
- $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
+ my $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
push @newpieces, $pc;
};
$newpiece->('',
OldIx => 0,
New => $new_upstream,
- };
- while (@ARGV) {
+ );
+ while (@ARGV && $ARGV[0] !~ m{^-}) {
my $n = shift @ARGV;
+
+ badusage "for each EXTRA-UPS-NAME need EXTRA-UPS-COMMITISH"
+ unless @ARGV && $ARGV[0] !~ m{^-};
+
my $c = git_rev_parse shift @ARGV;
die unless $n =~ m/^$extra_orig_namepart_re$/;
$newpiece->($n, New => $c);
# now we need to investigate the branch this generates the
# laundered version but we don't switch to it yet
my $old_head = get_head();
- my ($old_laundered_tip,$old_bw) = walk $old_head;
+ my ($old_laundered_tip,$old_bw,$old_upstream_update) = walk $old_head;
my $old_bw_cl = classify $old_bw;
- my $old_ups = parsecommit $old_bw_cl->{OrigParents}[0]{CommitId};
-
- my $problems = 0;
- my $problem = sub {
- my ($msg) = @_;
- $problems++;
- print STDERR "preflight check failed: $msg\n";
- };
+ my $old_upstream_update_cl = classify $old_upstream_update;
+ confess unless $old_upstream_update_cl->{OrigParents};
+ my $old_upstream = parsecommit
+ $old_upstream_update_cl->{OrigParents}[0]{CommitId};
- $piece->('', Old => $old_orig);
+ $piece->('', Old => $old_upstream->{CommitId});
- if ($old_orig_ci =~ m{^\[git-debrebase }m) {
- if ($old_orig_ci =~
- m{^\[git-debrebase new-upstream combine \.((?: $extra_orig_namepart_re)+)\]}
+ if ($old_upstream->{Msg} =~ m{^\[git-debrebase }m) {
+ if ($old_upstream->{Msg} =~
+ m{^\[git-debrebase (?:\w*-)?upstream combine \.((?: $extra_orig_namepart_re)+)\]}
) {
my @oldpieces = ('', split / /, $1);
- my $parentix = -1 + scalar @{ $old_orig->{Parents} };
- foreach my $i (0..$#$oldpieces) {
+ my $parentix = -1 + scalar @{ $old_upstream->{Parents} };
+ foreach my $i (0..$#oldpieces) {
my $n = $oldpieces[$i];
- $piece->($n, Old => $old_orig.'^'.$parentix);
+ $piece->($n, Old => $old_upstream->{CommitId}.'^'.$parentix);
}
} else {
- $problem->("previous upstream $old_orig->{CommitId} is from".
- " git-debrebase but not a \`new-upstream combine' commit");
+ fproblem "previous upstream $old_upstream->{CommitId} is from".
+ " git-debrebase but not an \`upstream combine' commit";
}
}
foreach my $pc (values %pieces) {
if (!$pc->{Old}) {
- $problem->("introducing upstream piece $pc->{Name}");
+ fproblem "introducing upstream piece \`$pc->{Name}'";
} elsif (!$pc->{New}) {
- $problem->("dropping upstream piece $pc->{Name}");
+ fproblem "dropping upstream piece \`$pc->{Name}'";
} elsif (!is_fast_fwd $pc->{Old}, $pc->{New}) {
- $problem->("not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}");
+ fproblem "not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}";
}
}
- if ($problems) {
- if ($opt_force) {
- printf STDERR
- "preflight check failures (%d) overriden by --force\n",
- $problems;
- } else {
- fail sprintf
- "preflight check failures (%d) (you could --force)",
- $problems;
- }
- }
+ printdebug "%pieces = ", (dd \%pieces), "\n";
+ printdebug "\@newpieces = ", (dd \@newpieces), "\n";
+
+ fproblems_maybe_bail();
+
+ my $new_bw;
fresh_workarea();
in_workarea sub {
my @upstream_merge_parents;
if (!$problems) {
- push @upstream_merge_parents, $old_orig->{CommitId};
+ push @upstream_merge_parents, $old_upstream->{CommitId};
}
foreach my $pc (@newpieces) { # always has '' first
if ($pc->{Name}) {
- read_tree_subdir $pcname, $pc->{New];
+ read_tree_subdir $pc->{Name}, $pc->{New};
} else {
runcmd @git, qw(read-tree), $pc->{New};
}
if (@newpieces > 1) {
# need to make the upstream subtree merge commit
- my $us_tree = cmdoutput @git, qw(write-tree);
- my @cmd = (@git, qw(commit-tree), $us_tree);
- push @cmd, qw(-p), $_ foreach @upstream_merge_parents;
- push @cmd, qw(-m), "Combine upstreams for $new_upstream_version";
- push @cmd, qw(-m),
- "[git-debrebase new-upstream combine . ".
- (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
- "]";
- $new_upstream = cmdoutput @cmd;
+ $new_upstream = make_commit \@upstream_merge_parents,
+ [ "Combine upstreams for $new_upstream_version",
+ ("[git-debrebase new-upstream combine . ".
+ (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
+ "]"),
+ ];
}
# $new_upstream is either the single upstream commit, or the
read_tree_subdir 'debian', "$old_bw:debian";
# index now contains the breakwater merge contents
-
- my $bw_tree = cmdoutput @git, qw(write_tree);
- my @cmd = (@git, qw(commit-tree), $bw_tree);
- push @cmd, qw(-p), $old_bw, qw(-p), $new_upstream;
- push @cmd, qw(-m), "Update to upstream $new_upstream_version";
- push @cmd, qw(-m),
- "[git-debrebase new-upstream breakwater $new_upstream_version]";
- my $new_bw = cmdoutput @git;
+ $new_bw = make_commit [ $old_bw, $new_upstream ],
+ [ "Update to upstream $new_upstream_version",
+ "[git-debrebase new-upstream breakwater $new_upstream_version]",
+ ];
# Now we have to add a changelog stanza so the Debian version
# is right.
-
die if unlink "debian";
- die unless $!==ENOTEMPTY;
- unlink "debian/changelog" or die $!;
+ die $! unless $!==ENOENT or $!==ENOTEMPTY;
+ unlink "debian/changelog" or $!==ENOENT or die $!;
+ mkdir "debian" or die $!;
open CN, ">", "debian/changelog" or die $!;
my $oldclog = git_cat_file ":debian/changelog";
$oldclog =~ m/^($package_re) \(\S+\) / or
fail "cannot parse old changelog to get package name";
my $p = $1;
- print CN, <<END, $oldclog or die $!;
+ print CN <<END, $oldclog or die $!;
$p ($new_version) UNRELEASED; urgency=medium
* Update to new upstream version $new_upstream_version.
runcmd @git, qw(update-index --add --replace), 'debian/changelog';
# Now we have the final new breakwater branch in the index
-
- $bw_tree = cmdoutput @git, qw(write_tree);
- @cmd = (@git, qw(commit-tree), $bw_tree);
- push @cmd, qw(-p), $new_bw;
- push @cmd, qw(-m),
- "Update changelog for new upstream $new_upstream_version";
- push @cmd, qw(-m),
- "[git-debrebase new-upstream changelog $new_upstream_version]";
- $new_bw = cmdoutput @git;
+ $new_bw = make_commit [ $new_bw ],
+ [ "Update changelog for new upstream $new_upstream_version",
+ "[git-debrebase new-upstream changelog $new_upstream_version]",
+ ];
};
# we have constructed the new breakwater. we now need to commit to
# the laundering output, because git-rebase can't easily be made
# to make a replay list which is based on some other branch
- update_head $old_head, $old_laundered;
+ update_head_postlaunder $old_head, $old_laundered_tip,
+ 'launder for new upstream';
- my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw);
+ my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw, @ARGV);
runcmd @cmd;
# now it's for the user to sort out
}
$rd = fresh_playground "$playprefix/misc";
-my $cmd = shift @ARGV;
-my $cmdfn = $cmd;
-$cmdfn =~ y/-/_/;
-$cmdfn = ${*::}{"cmd_$cmdfn"};
+if (!@ARGV || $ARGV[0] =~ m{^-}) {
+ defaultcmd_rebase();
+} else {
+ my $cmd = shift @ARGV;
+ my $cmdfn = $cmd;
+ $cmdfn =~ y/-/_/;
+ $cmdfn = ${*::}{"cmd_$cmdfn"};
-$cmdfn or badusage "unknown git-debrebase sub-operation $cmd";
-$cmdfn->();
+ $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";
+ $cmdfn->();
+}
~ianmdlvl / dgit.git / blobdiff