use the stricter PyMapping_Check (closes #15801)
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index d792529..413f9dd 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -1142,6 +1142,9 @@
self.checkraises(TypeError, '%10.*f', '__mod__', ('foo', 42.))
self.checkraises(ValueError, '%10', '__mod__', (42,))
+ class X(object): pass
+ self.checkraises(TypeError, 'abc', '__mod__', X())
+
def test_floatformatting(self):
# float formatting
for prec in range(100):
diff --git a/Misc/NEWS b/Misc/NEWS
index b333c0c..25be2aa 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
- Issue #15761: Fix crash when PYTHONEXECUTABLE is set on Mac OS X.
+- Issue #15801: Make sure mappings passed to '%' formatting are actually
+ subscriptable.
+
- Issue #15726: Fix incorrect bounds checking in PyState_FindModule.
Patch by Robin Schreiber.
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index b25b17b..8b782b4 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -9504,8 +9504,7 @@
arglen = -1;
argidx = -2;
}
- if (Py_TYPE(args)->tp_as_mapping && !PyTuple_Check(args) &&
- !PyUnicode_Check(args))
+ if (PyMapping_Check(args) && !PyTuple_Check(args) && !PyUnicode_Check(args))
dict = args;
while (--fmtcnt >= 0) {