dgit: Break out import_r1authline and change variable plumbing

Move the dicey parts into their own function.

If there are no origs, or import_r1authline didn't obtain the top
changelog entry, just call parsechangelog.

No overall functional change.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

1 files changed, 59 insertions, 52 deletions

diff --git a/dgit b/dgit
index 5afc791..4e8738f 100755
--- a/dgit
+++ b/dgit
@@ -2366,6 +2366,55 @@ sub dotdot_bpd_transfer_origs ($$$) {
     closedir DD;
 }
 
+sub import_r1authline ($$) {
+    my ($clogp_r, $upstreamv) = @_;
+    my $r1clogp;
+
+    my @clogcmd = qw(dpkg-parsechangelog --format rfc822 --all);
+
+    printdebug "import clog search...\n";
+    parsechangelog_loop \@clogcmd, (__ "package changelog"), sub {
+	my ($thisstanza, $desc) = @_;
+	no warnings qw(exiting);
+
+	$$clogp_r //= $thisstanza;
+
+	printdebug "import clog $thisstanza->{version} $desc...\n";
+
+	# We look for the first (most recent) changelog entry whose
+	# version number is lower than the upstream version of this
+	# package.  Then the last (least recent) previous changelog
+	# entry is treated as the one which introduced this upstream
+	# version and used for the synthetic commits for the upstream
+	# tarballs.
+
+	# One might think that a more sophisticated algorithm would be
+	# necessary.  But: we do not want to scan the whole changelog
+	# file.  Stopping when we see an earlier version, which
+	# necessarily then is an earlier upstream version, is the only
+	# realistic way to do that.  Then, either the earliest
+	# changelog entry we have seen so far is indeed the earliest
+	# upload of this upstream version; or there are only changelog
+	# entries relating to later upstream versions (which is not
+	# possible unless the changelog and .dsc disagree about the
+	# version).  Then it remains to choose between the physically
+	# last entry in the file, and the one with the lowest version
+	# number.  If these are not the same, we guess that the
+	# versions were created in a non-monotonic order rather than
+	# that the changelog entries have been misordered.
+
+	printdebug "import clog $thisstanza->{version} vs $upstreamv...\n";
+
+	last if version_compare($thisstanza->{version}, $upstreamv) < 0;
+	$r1clogp = $thisstanza;
+
+	printdebug "import clog $r1clogp->{version} becomes r1\n";
+    };
+
+    $r1clogp //= $$clogp_r; # maybe there's only one entry;
+    return clogp_authline $r1clogp;
+}
+
 sub import_tarball_tartrees ($$) {
     my ($upstreamv, $dfi) = @_;
     # cwd should be the playground
@@ -2486,65 +2535,23 @@ sub import_tarball_commits ($$) {
 
     my $any_orig = grep { $_->{Orig} } @$tartrees;
 
-    my @clogcmd = qw(dpkg-parsechangelog --format rfc822 --all);
     my $clogp;
-    my $r1clogp;
-
-    printdebug "import clog search...\n";
-    parsechangelog_loop \@clogcmd, (__ "package changelog"), sub {
-	my ($thisstanza, $desc) = @_;
-	no warnings qw(exiting);
-
-	$clogp //= $thisstanza;
-
-	printdebug "import clog $thisstanza->{version} $desc...\n";
-
-	last if !$any_orig; # we don't need $r1clogp
-
-	# We look for the first (most recent) changelog entry whose
-	# version number is lower than the upstream version of this
-	# package.  Then the last (least recent) previous changelog
-	# entry is treated as the one which introduced this upstream
-	# version and used for the synthetic commits for the upstream
-	# tarballs.
-
-	# One might think that a more sophisticated algorithm would be
-	# necessary.  But: we do not want to scan the whole changelog
-	# file.  Stopping when we see an earlier version, which
-	# necessarily then is an earlier upstream version, is the only
-	# realistic way to do that.  Then, either the earliest
-	# changelog entry we have seen so far is indeed the earliest
-	# upload of this upstream version; or there are only changelog
-	# entries relating to later upstream versions (which is not
-	# possible unless the changelog and .dsc disagree about the
-	# version).  Then it remains to choose between the physically
-	# last entry in the file, and the one with the lowest version
-	# number.  If these are not the same, we guess that the
-	# versions were created in a non-monotonic order rather than
-	# that the changelog entries have been misordered.
-
-	printdebug "import clog $thisstanza->{version} vs $upstreamv...\n";
-
-	last if version_compare($thisstanza->{version}, $upstreamv) < 0;
-	$r1clogp = $thisstanza;
-
-	printdebug "import clog $r1clogp->{version} becomes r1\n";
-    };
-
-    $clogp or fail __ "package changelog has no entries!";
-
+    my $r1authline;
+    if ($any_orig) {
+	$r1authline = import_r1authline(\$clogp, $upstreamv);
+	$clogp or fail __ "package changelog has no entries!";
+    }
+    # Runs if $any_orig clause didn't set $clogp
+    $clogp //= parsechangelog();
     my $authline = clogp_authline $clogp;
+    # Runs if $any_orig clause didn't set $r1authline
+    $r1authline //= $authline;
+
     my $changes = getfield $clogp, 'Changes';
     $changes =~ s/^\n//; # Changes: \n
     my $cversion = getfield $clogp, 'Version';
 
-    my $r1authline;
     if (@$tartrees) {
-	$r1clogp //= $clogp; # maybe there's only one entry;
-        $r1authline = clogp_authline $r1clogp;
-	# Strictly, r1authline might now be wrong if it's going to be
-	# unused because !$any_orig.  Whatever.
-
 	printdebug "import tartrees authline   $authline\n";
 	printdebug "import tartrees r1authline $r1authline\n";