From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 29 Jun 2019 16:08:39 +0000 (+0100)
Subject: Dgit.pm: read_tree_*: Treat '' as meaning 'delete this'
X-Git-Tag: archive/debian/9.0~50
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=commitdiff_plain;h=c974b978761dfae45cf673ca0a7852f21bc39956

Dgit.pm: read_tree_*: Treat '' as meaning 'delete this'

No functional change with existing callers.

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

diff --git a/Debian/Dgit.pm b/Debian/Dgit.pm
index d60de77b..887fbb59 100644
--- a/Debian/Dgit.pm
+++ b/Debian/Dgit.pm
@@ -689,8 +689,11 @@ sub rm_subdir_cached ($) {
 
 sub read_tree_subdir ($$) {
     my ($subdir, $new_tree_object) = @_;
+    # If $new_tree_object is '', the subtree is deleted.
+    confess unless defined $new_tree_object;
     rm_subdir_cached $subdir;
-    runcmd qw(git read-tree), "--prefix=$subdir/", $new_tree_object;
+    runcmd qw(git read-tree), "--prefix=$subdir/", $new_tree_object
+	if length $new_tree_object;
 }
 
 sub read_tree_debian ($) {
@@ -702,9 +705,10 @@ sub read_tree_debian ($) {
 sub read_tree_upstream ($;$$) {
     my ($treeish, $keep_patches, $tree_with_debian) = @_;
     # if $tree_with_debian is supplied, will use that for debian/
-    # otherwise will save and restore it.
+    # otherwise will save and restore it.  If $tree_with_debian
+    # is '' then debian/ is deleted.
     my $debian =
-	$tree_with_debian ? "$tree_with_debian:debian"
+	defined $tree_with_debian ? "$tree_with_debian:debian"
 	: cmdoutput qw(git write-tree --prefix=debian/);
     runcmd qw(git read-tree), $treeish;
     read_tree_subdir 'debian', $debian;