Fix parsing for an environment file with newlines

Fixes the new, purposely broken test added in the previous commit.

Signed-off-by: Jon Cotton <[email protected]>

Author: joncotton

docker/utils/utils.py

@@ -1069,7 +1069,11 @@ def parse_env_file(env_file):
             if line[0] == '#':
                 continue
 
-            parse_line = line.strip().split('=', 1)
+            line = line.strip()
+            if not line:
+                continue
+
+            parse_line = line.split('=', 1)
             if len(parse_line) == 2:
                 k, v = parse_line
                 environment[k] = v

tests/unit/utils_test.py

@@ -467,10 +467,18 @@ def test_parse_env_file_with_equals_character(self):
     def test_parse_env_file_commented_line(self):
         env_file = self.generate_tempfile(
             file_content='USER=jdoe\n#PASS=secret')
-        get_parse_env_file = parse_env_file((env_file))
+        get_parse_env_file = parse_env_file(env_file)
         self.assertEqual(get_parse_env_file, {'USER': 'jdoe'})
         os.unlink(env_file)
 
+    def test_parse_env_file_newline(self):
+        env_file = self.generate_tempfile(
+            file_content='\nUSER=jdoe\n\n\nPASS=secret')
+        get_parse_env_file = parse_env_file(env_file)
+        self.assertEqual(get_parse_env_file,
+                         {'USER': 'jdoe', 'PASS': 'secret'})
+        os.unlink(env_file)
+
     def test_parse_env_file_invalid_line(self):
         env_file = self.generate_tempfile(
             file_content='USER jdoe')