dh_strip: Fix bug generating Build-Id field with --dbg-package

The problem occurred because we overrode the list of recorded
build-ids after each package.  This works perfectly fine for dbgsym
packages as they always have a 1:1 with the original package.
However, a manual --dbg-package can host debug symbols for multiple
binary packages.

There are two paths to triggering this issue:

  dh_strip -p pkg1 -p pkg2 --dbg-package=foo-dbg

and:

  dh_strip -p pkg1 --dbg-package=foo-dbg
  dh_strip -p pkg2 --dbg-package=foo-dbg

  (This case was observed in krb5/1.15.2-2 where it loops over most of
  the packages and calls dh_strip on each of them with the same
  --dbg-package parameter.)

They fundamentally have the same issue and fix but the second case is
slightly more involved (as we have to merge with the previous run).

Signed-off-by: Niels Thykier <niels@thykier.net>

1 files changed, 17 insertions, 13 deletions

diff --git a/dh_strip b/dh_strip
index 6261c83d..420031ba 100755
--- a/dh_strip
+++ b/dh_strip
@@ -245,6 +245,16 @@ sub testfile {
 	}
 }
 
+sub write_buildid_file {
+	my ($package, $build_ids) = @_;
+	my $dir = "debian/.debhelper/${package}";
+	my $path = "${dir}/dbgsym-build-ids";
+	install_dir($dir);
+	open(my $fd, '>>', $path) or error("open $path failed: $!");
+	print {$fd} join(q{ }, sort(@{$build_ids})) . ' ';
+	close($fd) or error("close $path failed: $!");
+}
+
 # I could just use `file $_[0]`, but this is safer
 sub get_file_type {
 	my ($file, $cache_ok) = @_;
@@ -337,7 +347,7 @@ sub process_packages {
 				$use_build_id = 2;
 			}
 		}
-		%file_output=@shared_libs=@executables=@static_libs=@build_ids=();
+		%file_output=@shared_libs=@executables=@static_libs=();
 		find({
 			wanted => \&testfile,
 			no_chdir => 1,
@@ -387,20 +397,14 @@ sub process_packages {
 				close($fd) or error("close $path failed: $!");
 			}
 		}
-		if (@build_ids && ($use_build_id > 1 || $dh{DEBUGPACKAGE})) {
-			my ($dir, $path);
-			if ($use_build_id > 1) {
-				$dir = "debian/.debhelper/${package}";
-			} else {
-				$dir = "debian/.debhelper/$dh{DEBUGPACKAGE}";
-			}
-			$path = "${dir}/dbgsym-build-ids";
-			install_dir($dir);
-			open(my $fd, '>>', $path) or error("open $path failed: $!");
-			print {$fd} join(q{ }, sort(@build_ids)) . "\n";
-			close($fd) or error("close $path failed: $!");
+		if ($use_build_id > 1 and @build_ids) {
+			write_buildid_file($package, \@build_ids);
+			@build_ids = ();
 		}
 	}
+	if (@build_ids and $dh{DEBUGPACKAGE}) {
+		write_buildid_file($dh{DEBUGPACKAGE}, \@build_ids);
+	}
 }
 
 if ($dh{DEBUGPACKAGE}) {