diff options
author | Ian Jackson <ijackson@chiark.greenend.org.uk> | 2018-08-25 01:05:22 +0100 |
---|---|---|
committer | Ian Jackson <ijackson@chiark.greenend.org.uk> | 2018-08-25 12:26:51 +0100 |
commit | 2da6bc9c434e12dd33e4506c3eaf605b87ec30d8 (patch) | |
tree | d61f8e68a06f99a910ef989ed18ef2c2b6113d21 | |
parent | d7f555bf5c00a135d3991e9829450c4de73cafaa (diff) |
dgit: Replace branch_is_gdr with a history walker
The debrebase-last approach is fundamentally wrong, because, for
example, cloning a stitched laundered gdr branch from a git server
does not establish debrebase-last, so dgit would make patches
itself (slowly).
So, instead, use git-debrebase make-patches in situations where it
will succeed. We could just run it but that's slower, and it is a bit
awkward because we have to consider whether gdr is installed. So
provide our own implementation. It can be simpler because it only has
to handle the easy cases;
On testing of the new algorithm: we want to be confident that this
doesn't misfire; otherwise dgit users could be inconvenienced. And we
want it to work for gdr users of course.
We can analyse the test coverage of the logic in branch_is_gdr
by running the whole test suite and then comparing this:
cat tests/tmp/*.log |perl -ne 'next unless s/^branch_is_gdr \w+ //; print' |sort -u |less
with this:
git-grep 'branch_is_gdr ' | perl -pe 's/^^dgit:\s+//' |sort |less
Noting that we should ideally have one each of all the gdr kinds we
try to recognise. Currently that shows that we are missing only:
gdr merged-breakwater
unmarked BreakwaterStart YES
Closes: #907208.
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
-rwxr-xr-x | dgit | 81 |
1 files changed, 73 insertions, 8 deletions
@@ -308,13 +308,6 @@ sub branch_gdr_info ($$) { return ($ffq_prev, $gdrlast); } -sub branch_is_gdr ($$) { - my ($symref, $head) = @_; - my ($ffq_prev, $gdrlast) = branch_gdr_info($symref, $head); - return 0 unless $ffq_prev || $gdrlast; - return 1; -} - sub branch_is_gdr_unstitched_ff ($$$) { my ($symref, $head, $ancestor) = @_; my ($ffq_prev, $gdrlast) = branch_gdr_info($symref, $head); @@ -323,6 +316,78 @@ sub branch_is_gdr_unstitched_ff ($$$) { return 1; } +sub branch_is_gdr ($) { + my ($head) = @_; + # This is quite like git-debrebase's keycommits. + # We have our own implementation because: + # - our algorighm can do fewer tests so is faster + # - it saves testing to see if gdr is installed + my $walk = $head; + local $Debian::Dgit::debugcmd_when_debuglevel = 3; + printdebug "branch_is_gdr $head...\n"; + my $get_patches = sub { + my $t = git_cat_file "$_[0]:debian/patches", [qw(missing tree)]; + return $t // ''; + }; + my $tip_patches = $get_patches->($head); + WALK: + for (;;) { + my $cdata = git_cat_file $walk, 'commit'; + my ($hdrs,$msg) = $cdata =~ m{\n\n} ? ($`,$') : ($cdata,''); + if ($msg =~ m{^\[git-debrebase\ ( + anchor | pseudomerge | changelog | + make-patches | merged-breakwater + ) [: ] }mx) { + # no need to analyse this - it's sufficient + # (gdr classifications: Anchor, MergedBreakwaters) + # (made by gdr: Pseudomerge, Changelog) + printdebug "branch_is_gdr $walk gdr $1 YES\n"; + return 1; + } + my @parents = ($hdrs =~ m/^parent (\w+)$/gm); + if (@parents==2) { + my $walk_tree = get_tree_of_commit $walk; + foreach my $p (@parents) { + my $p_tree = get_tree_of_commit $p; + if ($p_tree eq $walk_tree) { # pseudomerge contriburor + # (gdr classification: Pseudomerge; not made by gdr) + printdebug "branch_is_gdr $walk unmarked pseudomerge\n" + if $debuglevel >= 2; + $walk = $p; + next WALK; + } + } + # some other non-gdr merge + # (gdr classification: VanillaMerge, DgitImportUnpatched, ?) + printdebug "branch_is_gdr $walk ?-2-merge NO\n"; + return 0; + } + if (@parents>2) { + # (gdr classification: ?) + printdebug "branch_is_gdr $walk ?-octopus NO\n"; + return 0; + } + if ($get_patches->($walk) ne $tip_patches) { + # Our parent added, removed, or edited patches, and wasn't + # a gdr make-patches commit. gdr make-patches probably + # won't do that well, then. + # (gdr classification of parent: AddPatches or ?) + printdebug "branch_is_gdr $walk ?-patches NO\n"; + return 0; + } + if ($tip_patches eq '' and + !defined git_cat_file "$walk:debian") { + # (gdr classification of parent: BreakwaterStart + printdebug "branch_is_gdr $walk unmarked BreakwaterStart YES\n"; + return 1; + } + # (gdr classification: Upstream Packaging Mixed Changelog) + printdebug "branch_is_gdr $walk plain\n" + if $debuglevel >= 2; + $walk = $parents[0]; + } +} + #---------- remote protocol support, common ---------- # remote push initiator/responder protocol: @@ -5548,7 +5613,7 @@ END if ($quilt_mode eq 'linear' && !$fopts->{'single-debian-patch'} - && branch_is_gdr($symref, $headref)) { + && branch_is_gdr($headref)) { # This is much faster. It also makes patches that gdr # likes better for future updates without laundering. # |