Detect tar-ignore in d/s/options

Distinguish situations where it's going to fail (until #908747 is
fixed), from ones where we are probably working with a defective tree
produced by importing a defective .dsc produced from a non-dgit
upload.

Closes: #1050709
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

1 files changed, 16 insertions, 1 deletions

diff --git a/dgit b/dgit
index 36055ed..122651d 100755
--- a/dgit
+++ b/dgit
@@ -7029,13 +7029,28 @@ sub build_or_push_prep_early () {
 }
 
 sub build_or_push_prep_modes () {
-    my ($format) = get_source_format();
+    my ($format, $fopts) = get_source_format();
     determine_whether_split_brain($format);
 
     fail __ "dgit: --include-dirty is not supported with split view".
             " (including with view-splitting quilt modes)"
 	if do_split_brain() && $includedirty;
 
+    if (grep m{^tar-ignore$}, @$fopts) {
+      if ((cmdoutput qw(git ls-files :.gitignore :*/.gitignore)) ne '') {
+	# The source package won't be faithful; bail with an explanation.
+        fail __ <<'END';
+tree has .gitignore(s) but debian/source/options has 'tar-ignore'
+Try 'tar-ignore=.git' in d/s/options instead.  (See #908747.)
+END
+      } else {
+	print STDERR f_ <<'END', $us;
+%s: warning: debian/source/options contains bare 'tar-ignore'
+This can cause .gitignore files to be improperly omitted.  See #908747.
+END
+      }
+    }
+
     if (madformat_wantfixup $format and $quilt_mode =~ m/baredebian$/) {
 	($quilt_upstream_commitish, $quilt_upstream_commitish_used,
 	 $quilt_upstream_commitish_message)