Reset default values when assigning the empty string to list setting

For list based settings, it makes more sense for the empty string
to get rid of any default value as well.

diff --git a/NEWS.md b/NEWS.md
index d34e565d9d467dce10895a2a93d1574481d2b987..df02819f6c38b4c9c883bdcd3ce37e1c671d4944 100644 (file)
--- a/NEWS.md
+++ b/NEWS.md
@@ -2,6 +2,8 @@
 
 ## v20
 
+- Assigning the empty string to a setting that takes a list of values
+  now overrides any configured default value as well.
 - The github action does not build and install systemd from source
   anymore. Instead, `ToolsTree=default` can be used to make sure a
   recent version of systemd is used to do the image build.

diff --git a/mkosi/config.py b/mkosi/config.py
index 7834a6073d3ac539b401dcb6212a813d88bb0ab5..442c96a664918e2a88c9cff397c01124e879da5b 100644 (file)
--- a/mkosi/config.py
+++ b/mkosi/config.py
@@ -636,7 +636,7 @@ def config_make_list_parser(delimiter: str,
 
         # Empty strings reset the list.
         if reset and len(values) == 1 and values[0] == "":
-            return None
+            return []
 
         return new + [parse(v) for v in values if v]
 

diff --git a/mkosi/resources/mkosi.md b/mkosi/resources/mkosi.md
index 2fd346f59111580e1811fc67b27c956a6c1f4a71..76bc2ee141eb01dbf14a52a516b89cdf963e4184 100644 (file)
--- a/mkosi/resources/mkosi.md
+++ b/mkosi/resources/mkosi.md
@@ -303,7 +303,8 @@ the earlier assignment would be used instead of later assignments.
 
 Settings that take a list of values are merged by appending the new
 values to the previously configured values. Assigning the empty string
-to such a setting removes all previously assigned values.
+to such a setting removes all previously assigned values, and overrides
+any configured default values as well.
 
 If a setting's name in the configuration file is prefixed with `@`, it
 configures the default value used for that setting if no explicit