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.
diff --git a/Lib/sre_parse.py b/Lib/sre_parse.py
index 3d38673..ab37fd3 100644
--- a/Lib/sre_parse.py
+++ b/Lib/sre_parse.py
@@ -395,7 +395,7 @@
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 @@
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 @@
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 @@
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 @@
'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 @@
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 4cdc591..3bd6d7b 100644
--- a/Lib/test/test_re.py
+++ b/Lib/test/test_re.py
@@ -5,7 +5,6 @@
import re
from re import Scanner
import sre_compile
-import sre_constants
import sys
import string
import traceback
@@ -186,18 +185,19 @@
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 @@
self.checkTemplateError('(?P<a>x)', r'\g<1a1>', 'xx',
"bad character in group name '1a1'", 3)
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',
- 'invalid group reference')
+ 'invalid group reference 2', 1)
with self.assertRaisesRegex(IndexError, "unknown group name 'ab'"):
re.sub('(?P<a>x)', r'\g<ab>', 'xx')
self.assertEqual(re.sub('(?P<a>x)|(?P<b>y)', r'\g<b>', 'xx'), '')
@@ -558,10 +558,11 @@
'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<a>)(?(%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<a>)(?(%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 @@
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 @@
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)