interpreter: fix interaction between option refactor and b_sanitize

If we return the default value of the `b_sanitize` option, it won't go
through the conversion back to string. This shows up in the ClangCL
implementation.

Fixes: #14501

1 files changed, 13 insertions, 3 deletions

diff --git a/mesonbuild/interpreter/interpreter.py b/mesonbuild/interpreter/interpreter.py
index 04de6fc6b..185bb07ee 100644
--- a/mesonbuild/interpreter/interpreter.py
+++ b/mesonbuild/interpreter/interpreter.py
@@ -1069,6 +1069,9 @@ class Interpreter(InterpreterBase, HoldableObject):
         if optname_regex.search(optname.split('.', maxsplit=1)[-1]) is not None:
             raise InterpreterException(f'Invalid option name {optname!r}')
 
+        # Will be None only if the value comes from the default
+        value_object: T.Optional[options.AnyOptionType]
+
         try:
             optkey = options.OptionKey(optname, self.subproject)
             value_object, value = self.coredata.optstore.get_value_object_and_value_for(optkey)
@@ -1076,7 +1079,14 @@ class Interpreter(InterpreterBase, HoldableObject):
             if self.coredata.optstore.is_base_option(optkey):
                 # Due to backwards compatibility return the default
                 # option for base options instead of erroring out.
-                return self.coredata.optstore.get_default_for_b_option(optkey)
+                #
+                # TODO: This will have issues if we expect to return a user FeatureOption
+                #       Of course, there's a bit of a layering violation here in
+                #       that we return a UserFeatureOption, but otherwise the held value
+                #       We probably need a lower level feature thing, or an enum
+                #       instead of strings
+                value = self.coredata.optstore.get_default_for_b_option(optkey)
+                value_object = None
             else:
                 if self.subproject:
                     raise MesonException(f'Option {optname} does not exist for subproject {self.subproject}.')
@@ -1087,7 +1097,7 @@ class Interpreter(InterpreterBase, HoldableObject):
             ocopy.value = value
             return ocopy
         elif optname == 'b_sanitize':
-            assert isinstance(value_object, options.UserStringArrayOption)
+            assert value_object is None or isinstance(value_object, options.UserStringArrayOption)
             # To ensure backwards compatibility this always returns a string.
             # We may eventually want to introduce a new "format" kwarg that
             # allows the user to modify this behaviour, but for now this is
@@ -1096,7 +1106,7 @@ class Interpreter(InterpreterBase, HoldableObject):
                 return 'none'
             return ','.join(sorted(value))
 
-        if isinstance(value_object.value, str):
+        if isinstance(value, str):
             return P_OBJ.OptionString(value, f'{{{optname}}}')
         return value