Make a copy of the snapcraft files common list before using it. (cano…

…nical#767)

LP: #1614913.

snapcraft/internal/sources.py

@@ -58,19 +58,20 @@
 
 """
 
-
+import copy
+import glob
 import logging
 import os
-import stat
 import os.path
+import stat
+import re
 import requests
 import shutil
-import tarfile
-import re
 import subprocess
 import tempfile
+import tarfile
 import zipfile
-import glob
+
 
 from snapcraft.internal import common
 from snapcraft import file_utils
@@ -357,7 +358,7 @@ def pull(self):
 
         def ignore(directory, files):
             if directory is source_abspath:
-                ignored = common.SNAPCRAFT_FILES
+                ignored = copy.copy(common.SNAPCRAFT_FILES)
                 relative_cwd = os.path.basename(os.getcwd())
                 if os.path.join(directory, relative_cwd) == os.getcwd():
                     # Source is a parent of the working directory.

snapcraft/tests/test_sources.py

@@ -14,14 +14,18 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import copy
 import os
 import http.server
 import threading
 import unittest.mock
 
 import fixtures
 
-from snapcraft.internal import sources
+from snapcraft.internal import (
+    common,
+    sources
+)
 from snapcraft import tests
 
 
@@ -385,6 +389,8 @@ def test_init_with_source_branch_and_tag_raises_exception(self):
 class TestLocal(tests.TestCase):
 
     def test_pull_with_source_a_parent_of_current_dir(self):
+        snapcraft_files_before_pull = copy.copy(common.SNAPCRAFT_FILES)
+
         # Verify that the snapcraft root dir does not get copied into itself.
         os.makedirs('subdir')
 
@@ -397,6 +403,12 @@ def test_pull_with_source_a_parent_of_current_dir(self):
         self.assertTrue(
             'subdir' not in os.listdir(os.path.join('subdir', 'foo')))
 
+        # Regression test for https://bugs.launchpad.net/snapcraft/+bug/1614913
+        # Verify that SNAPCRAFT_FILES was not modified by the pull when there
+        # are files to ignore.
+        self.assertEqual(
+            snapcraft_files_before_pull, common.SNAPCRAFT_FILES)
+
     def test_pull_with_existing_empty_source_dir_creates_hardlinks(self):
         os.makedirs(os.path.join('src', 'dir'))
         open(os.path.join('src', 'dir', 'file'), 'w').close()