mparser.py: actually check the type of key variable, not its value

Fixes PR #6166 and more specifically commit 4e460f04f3b2 that tried to
make sure the type of a key variable is a string but checked the type of
the value instead. Extends test common/228's limited coverage,
its only test case had (surprise) a string value. Also avoid reserved
python keyword 'dict' and potentially confusing string 'key'.

Implements #5231 for real.

1 files changed, 1 insertions, 1 deletions

diff --git a/mesonbuild/mparser.py b/mesonbuild/mparser.py
index 1baf051..80ffefd 100644
--- a/mesonbuild/mparser.py
+++ b/mesonbuild/mparser.py
@@ -682,7 +682,7 @@ class Parser:
                         # + 1 to colno to point to the actual string, not the opening quote
                         raise ParseException('Duplicate dictionary key: {}'.format(s.value), self.getline(), s.lineno, s.colno + 1)
                     a.set_kwarg(s.value, key_value)
-                elif isinstance(s, IdNode) and isinstance(key_value, StringNode):
+                elif isinstance(s, IdNode) and isinstance(s.value, str):
                     for key in a.kwargs:
                         if s.value == key.value:
                             raise ParseException('Duplicate dictionary variable key: {}'.format(s.value), self.getline(), s.lineno, s.colno)