repair install_mode support for uid/gid effectively everywhere

We silently dropped all integer values to install_mode since the
original implementation of doing this in KwargInfo, in commit
596c8d4af50d0e5a25ee0ee1e177e46b6c7ad22e.

This happened because install_mode is supposed to convert False
(exactly) to None, and otherwise pass all arguments in place. But a
generator is homogeneous and attempting to do this correctly produced a
mypy error that FileMode arguments were allowed to be ints -- well of
course they are -- so that resulted in the convertor... treating ints
like False instead, to make mypy happy.

Fixes #11538

1 files changed, 11 insertions, 2 deletions

diff --git a/mesonbuild/interpreter/type_checking.py b/mesonbuild/interpreter/type_checking.py
index beae001..2d2b916 100644
--- a/mesonbuild/interpreter/type_checking.py
+++ b/mesonbuild/interpreter/type_checking.py
@@ -97,8 +97,17 @@ def _install_mode_validator(mode: T.List[T.Union[str, bool, int]]) -> T.Optional
 def _install_mode_convertor(mode: T.Optional[T.List[T.Union[str, bool, int]]]) -> FileMode:
     """Convert the DSL form of the `install_mode` keyword argument to `FileMode`"""
 
-    # this has already been validated by the validator
-    return FileMode(*(m if isinstance(m, str) else None for m in mode))
+    if not mode:
+        return FileMode()
+
+    # This has already been validated by the validator. False denotes "use
+    # default". mypy is totally incapable of understanding it, because
+    # generators clobber types via homogeneous return. But also we *must*
+    # convert the first element different from the rest
+    m1 = mode[0] if isinstance(mode[0], str) else None
+    rest = (m if isinstance(m, (str, int)) else None for m in mode[1:])
+
+    return FileMode(m1, *rest)
 
 
 def _lower_strlist(input: T.List[str]) -> T.List[str]: