Issue #25953: re.sub() now raises an error for invalid numerical group

reference in replacement template even if the pattern is not found in
the string.  Error message for invalid group reference now includes the
group index and the position of the reference.
Based on patch by SilentGhost.
This commit is contained in:
Serhiy Storchaka 2016-10-23 12:11:19 +03:00
parent 265dce6cbb
commit 662cef66d7
3 changed files with 38 additions and 29 deletions

View File

@ -395,7 +395,7 @@ def _escape(source, escape, state):
len(escape)) len(escape))
state.checklookbehindgroup(group, source) state.checklookbehindgroup(group, source)
return GROUPREF, group return GROUPREF, group
raise source.error("invalid group reference", len(escape)) raise source.error("invalid group reference %d" % group, len(escape) - 1)
if len(escape) == 2: if len(escape) == 2:
if c in ASCIILETTERS: if c in ASCIILETTERS:
raise source.error("bad escape %s" % escape, len(escape)) raise source.error("bad escape %s" % escape, len(escape))
@ -725,8 +725,8 @@ def _parse(source, state, verbose):
raise source.error("bad group number", raise source.error("bad group number",
len(condname) + 1) len(condname) + 1)
if condgroup >= MAXGROUPS: if condgroup >= MAXGROUPS:
raise source.error("invalid group reference", msg = "invalid group reference %d" % condgroup
len(condname) + 1) raise source.error(msg, len(condname) + 1)
state.checklookbehindgroup(condgroup, source) state.checklookbehindgroup(condgroup, source)
elif char in FLAGS or char == "-": elif char in FLAGS or char == "-":
# flags # flags
@ -883,7 +883,9 @@ def parse_template(source, pattern):
literals = [] literals = []
literal = [] literal = []
lappend = literal.append lappend = literal.append
def addgroup(index): def addgroup(index, pos):
if index > pattern.groups:
raise s.error("invalid group reference %d" % index, pos)
if literal: if literal:
literals.append(''.join(literal)) literals.append(''.join(literal))
del literal[:] del literal[:]
@ -916,9 +918,9 @@ def parse_template(source, pattern):
raise s.error("bad character in group name %r" % name, raise s.error("bad character in group name %r" % name,
len(name) + 1) from None len(name) + 1) from None
if index >= MAXGROUPS: if index >= MAXGROUPS:
raise s.error("invalid group reference", raise s.error("invalid group reference %d" % index,
len(name) + 1) len(name) + 1)
addgroup(index) addgroup(index, len(name) + 1)
elif c == "0": elif c == "0":
if s.next in OCTDIGITS: if s.next in OCTDIGITS:
this += sget() this += sget()
@ -939,7 +941,7 @@ def parse_template(source, pattern):
'range 0-0o377' % this, len(this)) 'range 0-0o377' % this, len(this))
lappend(chr(c)) lappend(chr(c))
if not isoctal: if not isoctal:
addgroup(int(this[1:])) addgroup(int(this[1:]), len(this) - 1)
else: else:
try: try:
this = chr(ESCAPES[this][1]) this = chr(ESCAPES[this][1])
@ -966,5 +968,5 @@ def expand_template(template, match):
for index, group in groups: for index, group in groups:
literals[index] = g(group) or empty literals[index] = g(group) or empty
except IndexError: except IndexError:
raise error("invalid group reference") raise error("invalid group reference %d" % index)
return empty.join(literals) return empty.join(literals)

View File

@ -5,7 +5,6 @@ import locale
import re import re
from re import Scanner from re import Scanner
import sre_compile import sre_compile
import sre_constants
import sys import sys
import string import string
import traceback import traceback
@ -186,18 +185,19 @@ class ReTests(unittest.TestCase):
r'octal escape value \777 outside of ' r'octal escape value \777 outside of '
r'range 0-0o377', 0) r'range 0-0o377', 0)
self.checkTemplateError('x', r'\1', 'x', 'invalid group reference') self.checkTemplateError('x', r'\1', 'x', 'invalid group reference 1', 1)
self.checkTemplateError('x', r'\8', 'x', 'invalid group reference') self.checkTemplateError('x', r'\8', 'x', 'invalid group reference 8', 1)
self.checkTemplateError('x', r'\9', 'x', 'invalid group reference') self.checkTemplateError('x', r'\9', 'x', 'invalid group reference 9', 1)
self.checkTemplateError('x', r'\11', 'x', 'invalid group reference') self.checkTemplateError('x', r'\11', 'x', 'invalid group reference 11', 1)
self.checkTemplateError('x', r'\18', 'x', 'invalid group reference') self.checkTemplateError('x', r'\18', 'x', 'invalid group reference 18', 1)
self.checkTemplateError('x', r'\1a', 'x', 'invalid group reference') self.checkTemplateError('x', r'\1a', 'x', 'invalid group reference 1', 1)
self.checkTemplateError('x', r'\90', 'x', 'invalid group reference') self.checkTemplateError('x', r'\90', 'x', 'invalid group reference 90', 1)
self.checkTemplateError('x', r'\99', 'x', 'invalid group reference') self.checkTemplateError('x', r'\99', 'x', 'invalid group reference 99', 1)
self.checkTemplateError('x', r'\118', 'x', 'invalid group reference') # r'\11' + '8' self.checkTemplateError('x', r'\118', 'x', 'invalid group reference 11', 1)
self.checkTemplateError('x', r'\11a', 'x', 'invalid group reference') self.checkTemplateError('x', r'\11a', 'x', 'invalid group reference 11', 1)
self.checkTemplateError('x', r'\181', 'x', 'invalid group reference') # r'\18' + '1' self.checkTemplateError('x', r'\181', 'x', 'invalid group reference 18', 1)
self.checkTemplateError('x', r'\800', 'x', 'invalid group reference') # r'\80' + '0' self.checkTemplateError('x', r'\800', 'x', 'invalid group reference 80', 1)
self.checkTemplateError('x', r'\8', '', 'invalid group reference 8', 1)
# in python2.3 (etc), these loop endlessly in sre_parser.py # in python2.3 (etc), these loop endlessly in sre_parser.py
self.assertEqual(re.sub('(((((((((((x)))))))))))', r'\11', 'x'), 'x') self.assertEqual(re.sub('(((((((((((x)))))))))))', r'\11', 'x'), 'x')
@ -271,9 +271,9 @@ class ReTests(unittest.TestCase):
self.checkTemplateError('(?P<a>x)', r'\g<1a1>', 'xx', self.checkTemplateError('(?P<a>x)', r'\g<1a1>', 'xx',
"bad character in group name '1a1'", 3) "bad character in group name '1a1'", 3)
self.checkTemplateError('(?P<a>x)', r'\g<2>', 'xx', self.checkTemplateError('(?P<a>x)', r'\g<2>', 'xx',
'invalid group reference') 'invalid group reference 2', 3)
self.checkTemplateError('(?P<a>x)', r'\2', 'xx', self.checkTemplateError('(?P<a>x)', r'\2', 'xx',
'invalid group reference') 'invalid group reference 2', 1)
with self.assertRaisesRegex(IndexError, "unknown group name 'ab'"): with self.assertRaisesRegex(IndexError, "unknown group name 'ab'"):
re.sub('(?P<a>x)', r'\g<ab>', 'xx') re.sub('(?P<a>x)', r'\g<ab>', 'xx')
self.assertEqual(re.sub('(?P<a>x)|(?P<b>y)', r'\g<b>', 'xx'), '') self.assertEqual(re.sub('(?P<a>x)|(?P<b>y)', r'\g<b>', 'xx'), '')
@ -558,10 +558,11 @@ class ReTests(unittest.TestCase):
'two branches', 10) 'two branches', 10)
def test_re_groupref_overflow(self): def test_re_groupref_overflow(self):
self.checkTemplateError('()', r'\g<%s>' % sre_constants.MAXGROUPS, 'xx', from sre_constants import MAXGROUPS
'invalid group reference', 3) self.checkTemplateError('()', r'\g<%s>' % MAXGROUPS, 'xx',
self.checkPatternError(r'(?P<a>)(?(%d))' % sre_constants.MAXGROUPS, 'invalid group reference %d' % MAXGROUPS, 3)
'invalid group reference', 10) self.checkPatternError(r'(?P<a>)(?(%d))' % MAXGROUPS,
'invalid group reference %d' % MAXGROUPS, 10)
def test_re_groupref(self): def test_re_groupref(self):
self.assertEqual(re.match(r'^(\|)?([^()]+)\1$', '|a|').groups(), self.assertEqual(re.match(r'^(\|)?([^()]+)\1$', '|a|').groups(),
@ -1007,7 +1008,7 @@ class ReTests(unittest.TestCase):
self.checkPatternError(r"\567", self.checkPatternError(r"\567",
r'octal escape value \567 outside of ' r'octal escape value \567 outside of '
r'range 0-0o377', 0) r'range 0-0o377', 0)
self.checkPatternError(r"\911", 'invalid group reference', 0) self.checkPatternError(r"\911", 'invalid group reference 91', 1)
self.checkPatternError(r"\x1", r'incomplete escape \x1', 0) self.checkPatternError(r"\x1", r'incomplete escape \x1', 0)
self.checkPatternError(r"\x1z", r'incomplete escape \x1', 0) self.checkPatternError(r"\x1z", r'incomplete escape \x1', 0)
self.checkPatternError(r"\u123", r'incomplete escape \u123', 0) self.checkPatternError(r"\u123", r'incomplete escape \u123', 0)
@ -1061,7 +1062,7 @@ class ReTests(unittest.TestCase):
self.checkPatternError(br"\567", self.checkPatternError(br"\567",
r'octal escape value \567 outside of ' r'octal escape value \567 outside of '
r'range 0-0o377', 0) r'range 0-0o377', 0)
self.checkPatternError(br"\911", 'invalid group reference', 0) self.checkPatternError(br"\911", 'invalid group reference 91', 1)
self.checkPatternError(br"\x1", r'incomplete escape \x1', 0) self.checkPatternError(br"\x1", r'incomplete escape \x1', 0)
self.checkPatternError(br"\x1z", r'incomplete escape \x1', 0) self.checkPatternError(br"\x1z", r'incomplete escape \x1', 0)

View File

@ -23,6 +23,12 @@ Core and Builtins
Library Library
------- -------
- Issue #25953: re.sub() now raises an error for invalid numerical group
reference in replacement template even if the pattern is not found in
the string. Error message for invalid group reference now includes the
group index and the position of the reference.
Based on patch by SilentGhost.
- Issue #18219: Optimize csv.DictWriter for large number of columns. - Issue #18219: Optimize csv.DictWriter for large number of columns.
Patch by Mariatta Wijaya. Patch by Mariatta Wijaya.