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Applying modified version of patch #1018386, which fixes 

some escaping bugs in SRE.
This commit is contained in:
Gustavo Niemeyer 2004-09-03 17:06:10 +00:00
parent ab9351bf36
commit a01a2ee933
3 changed files with 91 additions and 43 deletions
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3
Doc/lib/libre.tex
View File

@ -387,7 +387,8 @@ also accepted by the regular expression parser:
Octal escapes are included in a limited form: If the first digit is a
0, or if there are three octal digits, it is considered an octal
escape. Otherwise, it is a group reference.
escape. Otherwise, it is a group reference. As for string literals,
octal escapes are always at most three digits in length.
% Note the lack of a period in the section title; it causes problems

78
Lib/sre_parse.py
View File

@ -217,21 +217,11 @@ def isname(name):
# check that group name is a valid string
if not isident(name[0]):
return False
for char in name:
for char in name[1:]:
if not isident(char) and not isdigit(char):
return False
return True
def _group(escape, groups):
# check if the escape string represents a valid group
try:
gid = int(escape[1:])
if gid and gid < groups:
return gid
except ValueError:
pass
return None # not a valid group
def _class_escape(source, escape):
# handle escape code inside character class
code = ESCAPES.get(escape)
@ -241,7 +231,8 @@ def _class_escape(source, escape):
if code:
return code
try:
if escape[1:2] == "x":
c = escape[1:2]
if c == "x":
# hexadecimal escape (exactly two digits)
while source.next in HEXDIGITS and len(escape) < 4:
escape = escape + source.get()
@ -249,12 +240,14 @@ def _class_escape(source, escape):
if len(escape) != 2:
raise error, "bogus escape: %s" % repr("\\" + escape)
return LITERAL, int(escape, 16) & 0xff
elif escape[1:2] in OCTDIGITS:
elif c in OCTDIGITS:
# octal escape (up to three digits)
while source.next in OCTDIGITS and len(escape) < 5:
while source.next in OCTDIGITS and len(escape) < 4:
escape = escape + source.get()
escape = escape[1:]
return LITERAL, int(escape, 8) & 0xff
elif c in DIGITS:
raise error, "bogus escape: %s" % repr(escape)
if len(escape) == 2:
return LITERAL, ord(escape[1])
except ValueError:
@ -270,19 +263,20 @@ def _escape(source, escape, state):
if code:
return code
try:
if escape[1:2] == "x":
c = escape[1:2]
if c == "x":
# hexadecimal escape
while source.next in HEXDIGITS and len(escape) < 4:
escape = escape + source.get()
if len(escape) != 4:
raise ValueError
return LITERAL, int(escape[2:], 16) & 0xff
elif escape[1:2] == "0":
elif c == "0":
# octal escape
while source.next in OCTDIGITS and len(escape) < 4:
escape = escape + source.get()
return LITERAL, int(escape[1:], 8) & 0xff
elif escape[1:2] in DIGITS:
elif c in DIGITS:
# octal escape *or* decimal group reference (sigh)
if source.next in DIGITS:
escape = escape + source.get()
@ -291,9 +285,9 @@ def _escape(source, escape, state):
# got three octal digits; this is an octal escape
escape = escape + source.get()
return LITERAL, int(escape[1:], 8) & 0xff
# got at least one decimal digit; this is a group reference
group = _group(escape, state.groups)
if group:
# not an octal escape, so this is a group reference
group = int(escape[1:])
if group < state.groups:
if not state.checkgroup(group):
raise error, "cannot refer to open group"
return GROUPREF, group
@ -709,7 +703,8 @@ def parse_template(source, pattern):
break # end of replacement string
if this and this[0] == "\\":
# group
if this == "\\g":
c = this[1:2]
if c == "g":
name = ""
if s.match("<"):
while 1:
@ -723,6 +718,8 @@ def parse_template(source, pattern):
raise error, "bad group name"
try:
index = int(name)
if index < 0:
raise error, "negative group number"
except ValueError:
if not isname(name):
raise error, "bad character in group name"
@ -731,26 +728,23 @@ def parse_template(source, pattern):
except KeyError:
raise IndexError, "unknown group name"
a((MARK, index))
elif len(this) > 1 and this[1] in DIGITS:
code = None
while 1:
group = _group(this, pattern.groups+1)
if group:
if (s.next not in DIGITS or
not _group(this + s.next, pattern.groups+1)):
code = MARK, group
break
elif s.next in OCTDIGITS:
elif c == "0":
if s.next in OCTDIGITS:
this = this + sget()
if s.next in OCTDIGITS:
this = this + sget()
else:
break
if not code:
this = this[1:]
code = LITERAL, makechar(int(this[-6:], 8) & 0xff)
if code[0] is LITERAL:
literal(code[1])
else:
a(code)
literal(makechar(int(this[1:], 8) & 0xff))
elif c in DIGITS:
isoctal = False
if s.next in DIGITS:
this = this + sget()
if (c in OCTDIGITS and s.next in OCTDIGITS and
this[2] in OCTDIGITS):
this = this + sget()
isoctal = True
literal(makechar(int(this[1:], 8) & 0xff))
if not isoctal:
a((MARK, int(this[1:])))
else:
try:
this = makechar(ESCAPES[this][1])
@ -782,7 +776,7 @@ def expand_template(template, match):
for index, group in groups:
literals[index] = s = g(group)
if s is None:
raise IndexError
raise error, "unmatched group"
except IndexError:
raise error, "empty group"
raise error, "invalid group reference"
return sep.join(literals)

53
Lib/test/test_re.py
View File

@ -83,6 +83,48 @@ class ReTests(unittest.TestCase):
self.assertEqual(re.sub('\r\n', '\n', 'abc\r\ndef\r\n'),
'abc\ndef\n')
def test_sub_template_numeric_escape(self):
# bug 776311 and friends
self.assertEqual(re.sub('x', r'\0', 'x'), '\0')
self.assertEqual(re.sub('x', r'\000', 'x'), '\000')
self.assertEqual(re.sub('x', r'\001', 'x'), '\001')
self.assertEqual(re.sub('x', r'\008', 'x'), '\0' + '8')
self.assertEqual(re.sub('x', r'\009', 'x'), '\0' + '9')
self.assertEqual(re.sub('x', r'\111', 'x'), '\111')
self.assertEqual(re.sub('x', r'\117', 'x'), '\117')
self.assertEqual(re.sub('x', r'\1111', 'x'), '\1111')
self.assertEqual(re.sub('x', r'\1111', 'x'), '\111' + '1')
self.assertEqual(re.sub('x', r'\00', 'x'), '\x00')
self.assertEqual(re.sub('x', r'\07', 'x'), '\x07')
self.assertEqual(re.sub('x', r'\08', 'x'), '\0' + '8')
self.assertEqual(re.sub('x', r'\09', 'x'), '\0' + '9')
self.assertEqual(re.sub('x', r'\0a', 'x'), '\0' + 'a')
self.assertEqual(re.sub('x', r'\400', 'x'), '\0')
self.assertEqual(re.sub('x', r'\777', 'x'), '\377')
self.assertRaises(re.error, re.sub, 'x', r'\1', 'x')
self.assertRaises(re.error, re.sub, 'x', r'\8', 'x')
self.assertRaises(re.error, re.sub, 'x', r'\9', 'x')
self.assertRaises(re.error, re.sub, 'x', r'\11', 'x')
self.assertRaises(re.error, re.sub, 'x', r'\18', 'x')
self.assertRaises(re.error, re.sub, 'x', r'\1a', 'x')
self.assertRaises(re.error, re.sub, 'x', r'\90', 'x')
self.assertRaises(re.error, re.sub, 'x', r'\99', 'x')
self.assertRaises(re.error, re.sub, 'x', r'\118', 'x') # r'\11' + '8'
self.assertRaises(re.error, re.sub, 'x', r'\11a', 'x')
self.assertRaises(re.error, re.sub, 'x', r'\181', 'x') # r'\18' + '1'
self.assertRaises(re.error, re.sub, 'x', r'\800', 'x') # r'\80' + '0'
# in python2.3 (etc), these loop endlessly in sre_parser.py
self.assertEqual(re.sub('(((((((((((x)))))))))))', r'\11', 'x'), 'x')
self.assertEqual(re.sub('((((((((((y))))))))))(.)', r'\118', 'xyz'),
'xz8')
self.assertEqual(re.sub('((((((((((y))))))))))(.)', r'\11a', 'xyz'),
'xza')
def test_qualified_re_sub(self):
self.assertEqual(re.sub('a', 'b', 'aaaaa'), 'bbbbb')
self.assertEqual(re.sub('a', 'b', 'aaaaa', 1), 'baaaa')
@ -105,6 +147,7 @@ class ReTests(unittest.TestCase):
self.assertRaises(IndexError, re.sub, '(?P<a>x)', '\g<ab>', 'xx')
self.assertRaises(re.error, re.sub, '(?P<a>x)|(?P<b>y)', '\g<b>', 'xx')
self.assertRaises(re.error, re.sub, '(?P<a>x)|(?P<b>y)', '\\2', 'xx')
self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<-1>', 'xx')
def test_re_subn(self):
self.assertEqual(re.subn("(?i)b+", "x", "bbbb BBBB"), ('x x', 2))
@ -386,6 +429,16 @@ class ReTests(unittest.TestCase):
self.assertNotEqual(re.match(r"\x%02xz" % i, chr(i)+"z"), None)
self.assertRaises(re.error, re.match, "\911", "")
def test_sre_character_class_literals(self):
for i in [0, 8, 16, 32, 64, 127, 128, 255]:
self.assertNotEqual(re.match(r"[\%03o]" % i, chr(i)), None)
self.assertNotEqual(re.match(r"[\%03o0]" % i, chr(i)), None)
self.assertNotEqual(re.match(r"[\%03o8]" % i, chr(i)), None)
self.assertNotEqual(re.match(r"[\x%02x]" % i, chr(i)), None)
self.assertNotEqual(re.match(r"[\x%02x0]" % i, chr(i)), None)
self.assertNotEqual(re.match(r"[\x%02xz]" % i, chr(i)), None)
self.assertRaises(re.error, re.match, "[\911]", "")
def test_bug_113254(self):
self.assertEqual(re.match(r'(a)|(b)', 'b').start(1), -1)
self.assertEqual(re.match(r'(a)|(b)', 'b').end(1), -1)