Validate the time fields too; move the digit reader to module level

Author: tonghuaroot

Lib/_pydatetime.py

@@ -355,27 +355,30 @@ def _find_isoformat_datetime_separator(dtstr):
             return 8
 
 
+def _read_isoformat_component(s, n):
+    # The caller has verified the string is ASCII, so isdigit() matches only
+    # the ASCII digits accepted by the C parser.
+    if len(s) != n or not s.isdigit():
+        raise ValueError("Invalid isoformat string")
+    return int(s)
+
+
 def _parse_isoformat_date(dtstr):
     # It is assumed that this is an ASCII-only string of lengths 7, 8 or 10,
     # see the comment on Modules/_datetimemodule.c:_find_isoformat_datetime_separator
     if len(dtstr) not in (7, 8, 10):
         raise ValueError("Invalid isoformat string")
     if not dtstr.isascii():
-        raise ValueError(f"Invalid isoformat string: {dtstr!r}")
-    def _read(s, n):
-        # dtstr is ASCII, so isdigit() matches only ASCII digits.
-        if len(s) != n or not s.isdigit():
-            raise ValueError(f"Invalid isoformat string: {dtstr!r}")
-        return int(s)
-
-    year = _read(dtstr[0:4], 4)
+        raise ValueError("Invalid isoformat string")
+
+    year = _read_isoformat_component(dtstr[0:4], 4)
     has_sep = dtstr[4] == '-'
 
     pos = 4 + has_sep
     if dtstr[pos:pos + 1] == "W":
         # YYYY-?Www-?D?
         pos += 1
-        weekno = _read(dtstr[pos:pos + 2], 2)
+        weekno = _read_isoformat_component(dtstr[pos:pos + 2], 2)
         pos += 2
 
         dayno = 1
@@ -385,17 +388,17 @@ def _read(s, n):
 
             pos += has_sep
 
-            dayno = _read(dtstr[pos:pos + 1], 1)
+            dayno = _read_isoformat_component(dtstr[pos:pos + 1], 1)
 
         return list(_isoweek_to_gregorian(year, weekno, dayno))
     else:
-        month = _read(dtstr[pos:pos + 2], 2)
+        month = _read_isoformat_component(dtstr[pos:pos + 2], 2)
         pos += 2
         if (dtstr[pos:pos + 1] == "-") != has_sep:
             raise ValueError("Inconsistent use of dash separator")
 
         pos += has_sep
-        day = _read(dtstr[pos:pos + 2], 2)
+        day = _read_isoformat_component(dtstr[pos:pos + 2], 2)
 
         return [year, month, day]
 
@@ -413,7 +416,7 @@ def _parse_hh_mm_ss_ff(tstr):
         if (len_str - pos) < 2:
             raise ValueError("Incomplete time component")
 
-        time_comps[comp] = int(tstr[pos:pos+2])
+        time_comps[comp] = _read_isoformat_component(tstr[pos:pos+2], 2)
 
         pos += 2
         next_char = tstr[pos:pos+1]
@@ -455,6 +458,8 @@ def _parse_isoformat_time(tstr):
     len_str = len(tstr)
     if len_str < 2:
         raise ValueError("Isoformat time too short")
+    if not tstr.isascii():
+        raise ValueError("Invalid isoformat string")
 
     # This is equivalent to re.search('[+-Z]', tstr), but faster
     tz_pos = (tstr.find('-') + 1 or tstr.find('+') + 1 or tstr.find('Z') + 1)

Lib/test/datetimetester.py

@@ -2116,7 +2116,7 @@ def test_fromisoformat_fails(self):
             '2020123',          # 7 chars: day slice reads a 1-character tail
             '9999121',          # 7 chars: day slice reads a 1-character tail
             '2020-W2',          # 1-digit week number
-            '٢025-03-09'        # Unicode characters
+            '٢025-03-09',       # Unicode characters
             '2009\ud80002\ud80028',     # Separators are surrogate codepoints
         ]
 
@@ -3768,6 +3768,9 @@ def test_fromisoformat_fails_datetime(self):
             '2009-04-19T12:30:45-00:90:00', # Time zone field out from range
             '2009-04-19T12:30:45-00:00:90', # Time zone field out from range
             '2020-2020',                    # Ambiguous 9-char date portion
+            '2009-04-19T12:30:4٥',          # Unicode digit in the seconds
+            '20201212T0102٣٤',              # Unicode digits in the time (gh-152204)
+            '2009-04-19T12:30:45+0٥:00',    # Unicode digit in the timezone
         ]
 
         for bad_str in bad_strs: