Issue 6089: str.format raises SystemError.
diff --git a/Lib/test/test_str.py b/Lib/test/test_str.py
index 51d2680..5341af2 100644
--- a/Lib/test/test_str.py
+++ b/Lib/test/test_str.py
@@ -351,6 +351,10 @@
self.assertRaises(IndexError, "{:s}".format)
self.assertRaises(IndexError, "{}".format)
+ # issue 6089
+ self.assertRaises(ValueError, "{0[0]x}".format, [None])
+ self.assertRaises(ValueError, "{0[0](10)}".format, [None])
+
# can't have a replacement on the field name portion
self.assertRaises(TypeError, '{0[{1}]}'.format, 'abcdefg', 4)
diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
index 83bc584..99155ec 100644
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -1100,6 +1100,10 @@
self.assertRaises(IndexError, u"{:s}".format)
self.assertRaises(IndexError, u"{}".format)
+ # issue 6089
+ self.assertRaises(ValueError, u"{0[0]x}".format, [None])
+ self.assertRaises(ValueError, u"{0[0](10)}".format, [None])
+
# can't have a replacement on the field name portion
self.assertRaises(TypeError, u'{0[{1}]}'.format, u'abcdefg', 4)
diff --git a/Objects/stringlib/string_format.h b/Objects/stringlib/string_format.h
index ce7c909..ee6533e 100644
--- a/Objects/stringlib/string_format.h
+++ b/Objects/stringlib/string_format.h
@@ -375,8 +375,9 @@
*name_idx = get_integer(name);
break;
default:
- /* interal error, can't get here */
- assert(0);
+ /* Invalid character follows ']' */
+ PyErr_SetString(PyExc_ValueError, "Only '.' or '[' may "
+ "follow ']' in format field specifier");
return 0;
}