use append mode in symlink unit test

These tests currently fail despite using the original Gzipfile
compression path. The archives appear to overwrite instead the
passed archive instead of writing new objects.

diff --git a/testing/test_deltatar.py b/testing/test_deltatar.py
index b776d5b..f6e8095 100644 (file)
--- a/testing/test_deltatar.py
+++ b/testing/test_deltatar.py
@@ -1512,7 +1512,6 @@ class DeltaTarTest(BaseTest):
         Creates a full backup containing different varieties of symlinks. All
         of them must be filtered out.
         '''
-
         password, paramversion = self.ENCRYPTION or (None, None)
         deltatar = DeltaTar(mode=self.MODE, password=password,
                             crypto_paramversion=paramversion,
@@ -1537,7 +1536,7 @@ class DeltaTarTest(BaseTest):
             a.addfile(l)
             return name
 
-        with tarfile.open(tar_path,mode="w") as a:
+        with tarfile.open(tar_path,mode="a") as a:
             checkme = \
                 [ add_symlink(a, "symlinks/foo", "internal-file")
                 , add_symlink(a, "symlinks/bar", "/absolute/path")