Added format tests.

Fixed bug in alignment of negative numbers.
Whitespace normalization.

Lib/test/test_builtin.py

@@ -540,6 +540,7 @@ class BuiltinTest(unittest.TestCase):
         self.assertEqual(format(3.1415e-104, ""), str(3.1415e-104))
         self.assertEqual(format(-3.1415e-104, ""), str(-3.1415e-104))
         self.assertEqual(format(object, ""), str(object))
+        self.assertEqual(format(None, ""), str(None))
 
         # TypeError because self.__format__ returns the wrong type
         self.assertRaises(TypeError, format, H(), "")

Lib/test/test_long.py

@@ -497,13 +497,25 @@ class LongTest(unittest.TestCase):
         self.assertEqual(format(123456789, 'd'), '123456789')
         self.assertEqual(format(123456789, 'd'), '123456789')
 
+        # sign and aligning are interdependent
+        self.assertEqual(format(1, "-"), '1')
+        self.assertEqual(format(-1, "-"), '-1')
+        self.assertEqual(format(1, "-3"), '  1')
+        self.assertEqual(format(-1, "-3"), ' -1')
+        self.assertEqual(format(1, "+3"), ' +1')
+        self.assertEqual(format(-1, "+3"), ' -1')
+        self.assertEqual(format(1, " 3"), '  1')
+        self.assertEqual(format(-1, " 3"), ' -1')
+        self.assertEqual(format(1, " "), ' 1')
+        self.assertEqual(format(-1, " "), '-1')
+
         # hex
         self.assertEqual(format(3, "x"), "3")
         self.assertEqual(format(3, "X"), "3")
         self.assertEqual(format(1234, "x"), "4d2")
         self.assertEqual(format(-1234, "x"), "-4d2")
         self.assertEqual(format(1234, "8x"), "     4d2")
-# XXX fix       self.assertEqual(format(-1234, "8x"), "    -4d2")
+        self.assertEqual(format(-1234, "8x"), "    -4d2")
         self.assertEqual(format(1234, "x"), "4d2")
         self.assertEqual(format(-1234, "x"), "-4d2")
         self.assertEqual(format(-3, "x"), "-3")
@@ -530,7 +542,6 @@ class LongTest(unittest.TestCase):
 
         # make sure these are errors
         self.assertRaises(ValueError, format, 3, "1.3")  # precision disallowed
-        return
         self.assertRaises(ValueError, format, 3, "+c")   # sign not allowed
                                                          # with 'c'
         self.assertRaises(ValueError, format, 3, "R")    # bogus format type

Lib/test/test_unicode.py

@@ -379,8 +379,6 @@ class UnicodeTest(
         self.assertEqual("The year is {0.year}".format(d),
                          "The year is 2007")
 
-        #"{0!r:20}".format("Hello")
-
         # classes we'll use for testing
         class C:
             def __init__(self, x=100):
@@ -428,6 +426,10 @@ class UnicodeTest(
             def __format__(self, format_spec):
                 return self.strftime(format_spec)
 
+        class J(int):
+            def __format__(self, format_spec):
+                return int.__format__(self * 2, format_spec)
+
 
         self.assertEqual(''.format(), '')
         self.assertEqual('abc'.format(), 'abc')
@@ -465,12 +467,6 @@ class UnicodeTest(
         self.assertEqual('{0[1][0]}'.format(['abc', ['def']]), 'def')
         self.assertEqual('{0[1][0].x}'.format(['abc', [D('def')]]), 'def')
 
-        # I'm not sure if this should work, or if it's a problem if it does work
-        #'{0[_{foo}]}'.format({'_FOO': 'abc'}, foo='FOO')
-        #('{0[{foo}{bar}]}'.format({'FOOBAR': 'abc'}, foo='FOO', bar='BAR')
-
-        # format specifiers for built in types
-
         # strings
         self.assertEqual('{0:.3s}'.format('abc'), 'abc')
         self.assertEqual('{0:.3s}'.format('ab'), 'ab')
@@ -524,6 +520,10 @@ class UnicodeTest(
                                                        day=27)),
                          "date: 2007-08-27")
 
+        # test deriving from a builtin type and overriding __format__
+        self.assertEqual("{0}".format(J(10)), "20")
+
+
         # string format specifiers
         self.assertEqual('{0:}'.format('a'), 'a')
 

Objects/stringlib/formatter.h

@@ -145,8 +145,7 @@ parse_internal_render_format_spec(PyObject *format_spec,
     }
 
     /* The special case for 0-padding (backwards compat) */
-    if (format->fill_char == '\0' &&
+    if (format->fill_char == '\0' && end-ptr >= 1 && ptr[0] == '0') {
-            end-ptr >= 1 && ptr[0] == '0') {
         format->fill_char = '0';
         if (format->align == '\0') {
             format->align = '=';
@@ -298,9 +297,10 @@ calc_number_widths(NumberFieldWidths *r, STRINGLIB_CHAR actual_sign,
                 r->n_lpadding = padding / 2;
                 r->n_rpadding = padding - r->n_lpadding;
             }
-            else
+            else if (format->align == '=')
-                /* must be '=' */
                 r->n_spadding = padding;
+            else
+                r->n_lpadding = padding;
         }
     }
     r->n_total = r->n_lpadding + r->n_lsign + r->n_spadding +