use the stricter PyMapping_Check (closes #15801)

benjaminp · benjaminp · commit 28a6cfaefc41 · 2012-08-28T17:55:35.000-04:00
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
@@ -1142,6 +1142,9 @@ def test_formatting(self):
         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
@@ -12,6 +12,9 @@ Core and Builtins
 
 - 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
@@ -9504,8 +9504,7 @@ PyObject *PyUnicode_Format(PyObject *format,
         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) {

Original file line number	Diff line number	Diff line change
`@@ -9504,8 +9504,7 @@ PyObject PyUnicode_Format(PyObject format,`
`9504`	`9504`	`arglen = -1;`
`9505`	`9505`	`argidx = -2;`
`9506`	`9506`	`}`
`9507`		`- if (Py_TYPE(args)->tp_as_mapping && !PyTuple_Check(args) &&`
`9508`		`- !PyUnicode_Check(args))`
	`9507`	`+ if (PyMapping_Check(args) && !PyTuple_Check(args) && !PyUnicode_Check(args))`
`9509`	`9508`	`dict = args;`
`9510`	`9509`
`9511`	`9510`	`while (--fmtcnt >= 0) {`