git-debrebase: convert-from-gbp: Check separately for $dtag

This allows us to print a more sensible error message, Previously
git would print a fatal error, after which we carry on.

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

diff --git a/git-debrebase b/git-debrebase
index a19d258b48b5b0a1896bf59d96221b83aa828430..42e8f7e3eec152892c35cd87666147749eea03ee 100755 (executable)
--- a/git-debrebase
+++ b/git-debrebase
@@ -2481,6 +2481,8 @@ END
        is_fast_fwd $mtag, 'HEAD' or
            die "HEAD is not FF from maintainer tag $mtag!";
        my $dtag = "archive/$mtag";
+       git_get_ref "refs/tags/$dtag" or
+           die "dgit view tag $dtag not found\n";
        is_fast_fwd $mtag, $dtag or
            die "dgit view tag $dtag is not FF from maintainer tag $mtag\n";
        print "will stitch in dgit view, $dtag\n";