gh-158252: Use Unicode whitespace for strptime aliases

Use the same whitespace predicate as Python for %n, %t, and trimming
AM/PM indicators. Cover ASCII separators before adjacent numeric fields
in the alias formats.

Author: pganssle

Lib/test/test_strptime.py

@@ -54,6 +54,16 @@ def test_numeric_aliases(self):
         ):
             self.assert_matches_python(text, fmt)
 
+    def test_whitespace_aliases_before_adjacent_fields(self):
+        for separator in ('\x1c', '\x1d', '\x1e', '\x1f'):
+            for whitespace in ('%n', '%t'):
+                for field in ('%d', '%e'):
+                    self.assert_matches_python(f'2024{separator} 112',
+                                               f'%Y{whitespace}{field}%m')
+                for field in ('%H', '%k', '%I', '%l'):
+                    self.assert_matches_python(f'34{separator} 123',
+                                               f'%M{whitespace}{field}%S')
+
     def test_offsets_and_zone_names(self):
         offsets = ('', 'Z', '+0530', '-03:30', '+01:02:03', '-000001.000001',
                    '+01:02:03.456789', '+000000.5', '-00:00:00.5',

Python/_strptime.c

@@ -66,10 +66,10 @@ strptime_name(const unsigned char *data, Py_ssize_t length, Py_ssize_t pos,
         }
         char *start = name;
         if (directive == 'p') {
-            while (size && Py_ISSPACE(start[size - 1])) {
+            while (size && Py_UNICODE_ISSPACE(start[size - 1])) {
                 size--;
             }
-            while (size && Py_ISSPACE(*start)) {
+            while (size && Py_UNICODE_ISSPACE(*start)) {
                 start++;
                 size--;
             }
@@ -331,7 +331,7 @@ _PyTime_Strptime(PyObject *string, PyObject *format, _PyTime_StrptimeFields *fie
             continue;
         }
         if (c == 'n' || c == 't') {
-            while (pos < length && Py_ISSPACE(data[pos])) {
+            while (pos < length && Py_UNICODE_ISSPACE(data[pos])) {
                 pos++;
             }
             continue;