build: fix usage of append_env for variables that are not set

1 files changed, 7 insertions, 0 deletions

diff --git a/test/test_cerbero_build_build.py b/test/test_cerbero_build_build.py
index b7102080..1fad1bc5 100644
--- a/test/test_cerbero_build_build.py
+++ b/test/test_cerbero_build_build.py
@@ -57,6 +57,13 @@ class ModifyEnvTest(unittest.TestCase):
         val = self.mk.get_env_var(self.var)
         self.assertEquals(val, self.val1 + self.val2)
 
+    def testAppendNonExistentEnv(self):
+        if self.var in os.environ:
+            del os.environ[self.var]
+        self.mk.append_env = {self.var: self.val2}
+        val = self.mk.get_env_var(self.var)
+        self.assertEquals(val, self.val2)
+
     def testNewEnv(self):
         os.environ[self.var] = self.val1
         self.mk.new_env = {self.var: self.val2}