Close issue #8931: Make alternate formatting for 'c' raise an exception. Patch by...

diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py
index ec10752e6a2ae0eac233c1cdd9bf7cd8ed858b54..11d95465a81312a6b3afa47e1fbe803c8f6f6349 100644 (file)
--- a/Lib/test/test_types.py
+++ b/Lib/test/test_types.py
@@ -343,6 +343,8 @@ class TypesTests(unittest.TestCase):
         self.assertRaises(ValueError, 3 .__format__, ",n")
         # can't have ',' with 'c'
         self.assertRaises(ValueError, 3 .__format__, ",c")
+        # can't have '#' with 'c'
+        self.assertRaises(ValueError, 3 .__format__, "#c")
 
         # ensure that only int and float type specifiers work
         for format_spec in ([chr(x) for x in range(ord('a'), ord('z')+1)] +

diff --git a/Misc/NEWS b/Misc/NEWS
index 4da2333237b926a326941ded5af2088727b68af9..6d4a6e4eebc9998d4f59a9de4925311152907c3a 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -43,6 +43,10 @@ Core and Builtins
   replacement fields. It now matches the behavior of str.format() in
   this regard. Patches by Phil Elson and Ramchandra Apte.
 
+- Issue #8931: Make alternate formatting ('#') for type 'c' raise an
+  exception. In versions prior to 3.5, '#' with 'c' had no effect. Now
+  specifying it is an error.  Patch by Torsten Landschoff.
+
 Library
 -------
 

diff --git a/Python/formatter_unicode.c b/Python/formatter_unicode.c
index e3a814984151b6e85c9afec1c2a090bee0b22513..056bb76902597e8b959fa53dcd58386102b10c99 100644 (file)
--- a/Python/formatter_unicode.c
+++ b/Python/formatter_unicode.c
@@ -846,6 +846,13 @@ format_long_internal(PyObject *value, const InternalFormatSpec *format,
                             " format specifier 'c'");
             goto done;
         }
+        /* error to request alternate format */
+        if (format->alternate) {
+            PyErr_SetString(PyExc_ValueError,
+                            "Alternate form (#) not allowed with integer"
+                            " format specifier 'c'");
+            goto done;
+        }
 
         /* taken from unicodeobject.c formatchar() */
         /* Integer input truncated to a character */