Don't pass down empty lists to subimages unless explicitly configured

This makes sure that subimages use default values for list based
settings unless they were explicitly configured in configuration or
on the command line or have a non-empty default value in the main
image.

Fixes #2874

diff --git a/mkosi/config.py b/mkosi/config.py
index c919a3473c1c26d0faa19b0d9f897eac67e637f6..18c6a8ae5af398a528fa3d91aad96486df725aaf 100644 (file)
--- a/mkosi/config.py
+++ b/mkosi/config.py
@@ -3824,7 +3824,18 @@ def parse_config(argv: Sequence[str] = (), *, resources: Path = Path("/")) -> tu
         # were specified on the CLI by copying them to the CLI namespace. Any settings
         # that are not marked as "universal" are deleted from the CLI namespace.
         for s in SETTINGS:
-            if s.scope == SettingScope.universal:
+            if (
+                s.scope == SettingScope.universal and (
+                    # For list-based settings, don't pass down empty lists unless it came
+                    # explicitly from the config file or the CLI. This makes sure that default
+                    # values from subimages are still used if no value is explicitly configured
+                    # in the main image or on the CLI.
+                    not isinstance(getattr(config, s.dest), (list, dict, set)) or
+                    getattr(config, s.dest) or
+                    hasattr(context.cli, s.dest) or
+                    hasattr(context.config, s.dest)
+                )
+            ):
                 setattr(context.cli, s.dest, copy.deepcopy(getattr(config, s.dest)))
             elif hasattr(context.cli, s.dest):
                 delattr(context.cli, s.dest)

diff --git a/tests/test_config.py b/tests/test_config.py
index abd70805cf45e36855285723e7504b5d1ae25c6c..20db168af1c8f0d5add419e19dae2059f0077466 100644 (file)
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -262,6 +262,7 @@ def test_parse_config(tmp_path: Path) -> None:
     )
 
     (d / "mkosi.images/two").mkdir()
+    (d / "mkosi.images/two/mkosi.skeleton").mkdir()
     (d / "mkosi.images/two/mkosi.conf").write_text(
         """
         [Distribution]
@@ -302,6 +303,10 @@ def test_parse_config(tmp_path: Path) -> None:
     assert one.image_version == "1.2.3"
     assert two.image_version == "4.5.6"
 
+    # Default values from subimages should be picked up.
+    assert len(one.package_manager_trees) == 0
+    assert len(two.package_manager_trees) == 1 and two.package_manager_trees[0].source.name == "mkosi.skeleton"
+
     with chdir(d):
         _, [one, two, config] = parse_config(["--image-version", "7.8.9"])