Merged revisions 72848 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r72848 | eric.smith | 2009-05-23 09:56:13 -0400 (Sat, 23 May 2009) | 1 line

  Issue 6089: str.format raises SystemError.
........

Lib/test/test_unicode.py

@@ -688,6 +688,10 @@ class UnicodeTest(
         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)
 

Misc/NEWS

@@ -12,6 +12,9 @@ What's New in Python 3.1 release candidate 1?
 Core and Builtins
 -----------------
 
+- Issue #6089: Fixed str.format with certain invalid field specifiers
+  that would raise SystemError.
+
 - Issue #5829: complex("1e500") no longer raises OverflowError.  This
   makes it consistent with float("1e500") and interpretation of real
   and imaginary literals.

Objects/stringlib/string_format.h

@@ -375,8 +375,9 @@ FieldNameIterator_next(FieldNameIterator *self, int *is_attribute,
         *name_idx = get_integer(name);
         break;
     default:
-        /* interal error, can't get here */
+        /* Invalid character follows ']' */
-        assert(0);
+        PyErr_SetString(PyExc_ValueError, "Only '.' or '[' may "
+                        "follow ']' in format field specifier");
         return 0;
     }