From 662cef66d7e90ec3c391a5b5ab933c159ef009b6 Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Sun, 23 Oct 2016 12:11:19 +0300 Subject: [PATCH] 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. --- Lib/sre_parse.py | 18 ++++++++++-------- Lib/test/test_re.py | 43 ++++++++++++++++++++++--------------------- Misc/NEWS | 6 ++++++ 3 files changed, 38 insertions(+), 29 deletions(-) diff --git a/Lib/sre_parse.py b/Lib/sre_parse.py index 3d38673c322..ab37fd3fe2f 100644 --- a/Lib/sre_parse.py +++ b/Lib/sre_parse.py @@ -395,7 +395,7 @@ def _escape(source, escape, state): len(escape)) state.checklookbehindgroup(group, source) 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 c in ASCIILETTERS: raise source.error("bad escape %s" % escape, len(escape)) @@ -725,8 +725,8 @@ def _parse(source, state, verbose): raise source.error("bad group number", len(condname) + 1) if condgroup >= MAXGROUPS: - raise source.error("invalid group reference", - len(condname) + 1) + msg = "invalid group reference %d" % condgroup + raise source.error(msg, len(condname) + 1) state.checklookbehindgroup(condgroup, source) elif char in FLAGS or char == "-": # flags @@ -883,7 +883,9 @@ def parse_template(source, pattern): literals = [] literal = [] 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: literals.append(''.join(literal)) del literal[:] @@ -916,9 +918,9 @@ def parse_template(source, pattern): raise s.error("bad character in group name %r" % name, len(name) + 1) from None if index >= MAXGROUPS: - raise s.error("invalid group reference", + raise s.error("invalid group reference %d" % index, len(name) + 1) - addgroup(index) + addgroup(index, len(name) + 1) elif c == "0": if s.next in OCTDIGITS: this += sget() @@ -939,7 +941,7 @@ def parse_template(source, pattern): 'range 0-0o377' % this, len(this)) lappend(chr(c)) if not isoctal: - addgroup(int(this[1:])) + addgroup(int(this[1:]), len(this) - 1) else: try: this = chr(ESCAPES[this][1]) @@ -966,5 +968,5 @@ def expand_template(template, match): for index, group in groups: literals[index] = g(group) or empty except IndexError: - raise error("invalid group reference") + raise error("invalid group reference %d" % index) return empty.join(literals) diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py index 4cdc59127a1..3bd6d7b461c 100644 --- a/Lib/test/test_re.py +++ b/Lib/test/test_re.py @@ -5,7 +5,6 @@ import locale import re from re import Scanner import sre_compile -import sre_constants import sys import string import traceback @@ -186,18 +185,19 @@ class ReTests(unittest.TestCase): r'octal escape value \777 outside of ' r'range 0-0o377', 0) - self.checkTemplateError('x', r'\1', 'x', 'invalid group reference') - self.checkTemplateError('x', r'\8', 'x', 'invalid group reference') - self.checkTemplateError('x', r'\9', 'x', 'invalid group reference') - self.checkTemplateError('x', r'\11', 'x', 'invalid group reference') - self.checkTemplateError('x', r'\18', 'x', 'invalid group reference') - self.checkTemplateError('x', r'\1a', 'x', 'invalid group reference') - self.checkTemplateError('x', r'\90', 'x', 'invalid group reference') - self.checkTemplateError('x', r'\99', 'x', 'invalid group reference') - self.checkTemplateError('x', r'\118', 'x', 'invalid group reference') # r'\11' + '8' - self.checkTemplateError('x', r'\11a', 'x', 'invalid group reference') - self.checkTemplateError('x', r'\181', 'x', 'invalid group reference') # r'\18' + '1' - self.checkTemplateError('x', r'\800', 'x', 'invalid group reference') # r'\80' + '0' + self.checkTemplateError('x', r'\1', 'x', 'invalid group reference 1', 1) + self.checkTemplateError('x', r'\8', 'x', 'invalid group reference 8', 1) + self.checkTemplateError('x', r'\9', 'x', 'invalid group reference 9', 1) + self.checkTemplateError('x', r'\11', 'x', 'invalid group reference 11', 1) + self.checkTemplateError('x', r'\18', 'x', 'invalid group reference 18', 1) + self.checkTemplateError('x', r'\1a', 'x', 'invalid group reference 1', 1) + self.checkTemplateError('x', r'\90', 'x', 'invalid group reference 90', 1) + self.checkTemplateError('x', r'\99', 'x', 'invalid group reference 99', 1) + self.checkTemplateError('x', r'\118', 'x', 'invalid group reference 11', 1) + self.checkTemplateError('x', r'\11a', 'x', 'invalid group reference 11', 1) + self.checkTemplateError('x', r'\181', 'x', 'invalid group reference 18', 1) + 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 self.assertEqual(re.sub('(((((((((((x)))))))))))', r'\11', 'x'), 'x') @@ -271,9 +271,9 @@ class ReTests(unittest.TestCase): self.checkTemplateError('(?Px)', r'\g<1a1>', 'xx', "bad character in group name '1a1'", 3) self.checkTemplateError('(?Px)', r'\g<2>', 'xx', - 'invalid group reference') + 'invalid group reference 2', 3) self.checkTemplateError('(?Px)', r'\2', 'xx', - 'invalid group reference') + 'invalid group reference 2', 1) with self.assertRaisesRegex(IndexError, "unknown group name 'ab'"): re.sub('(?Px)', r'\g', 'xx') self.assertEqual(re.sub('(?Px)|(?Py)', r'\g', 'xx'), '') @@ -558,10 +558,11 @@ class ReTests(unittest.TestCase): 'two branches', 10) def test_re_groupref_overflow(self): - self.checkTemplateError('()', r'\g<%s>' % sre_constants.MAXGROUPS, 'xx', - 'invalid group reference', 3) - self.checkPatternError(r'(?P)(?(%d))' % sre_constants.MAXGROUPS, - 'invalid group reference', 10) + from sre_constants import MAXGROUPS + self.checkTemplateError('()', r'\g<%s>' % MAXGROUPS, 'xx', + 'invalid group reference %d' % MAXGROUPS, 3) + self.checkPatternError(r'(?P)(?(%d))' % MAXGROUPS, + 'invalid group reference %d' % MAXGROUPS, 10) def test_re_groupref(self): self.assertEqual(re.match(r'^(\|)?([^()]+)\1$', '|a|').groups(), @@ -1007,7 +1008,7 @@ class ReTests(unittest.TestCase): self.checkPatternError(r"\567", r'octal escape value \567 outside of ' 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"\x1z", r'incomplete escape \x1', 0) self.checkPatternError(r"\u123", r'incomplete escape \u123', 0) @@ -1061,7 +1062,7 @@ class ReTests(unittest.TestCase): self.checkPatternError(br"\567", r'octal escape value \567 outside of ' 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"\x1z", r'incomplete escape \x1', 0) diff --git a/Misc/NEWS b/Misc/NEWS index b29d0620a77..0021b19ac41 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -23,6 +23,12 @@ Core and Builtins 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. Patch by Mariatta Wijaya.