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Issues #814253, #9179: Warnings now are raised when group references and

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conditional group references are used in lookbehind assertions in regular
expressions.
This commit is contained in:
Serhiy Storchaka 2015-02-21 12:08:52 +02:00
parent a1543cdcd6
commit a3369a524c
4 changed files with 61 additions and 3 deletions
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20
Lib/sre_parse.py
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@ -69,6 +69,8 @@ class Pattern:
self.open = []
self.groups = 1
self.groupdict = {}
self.lookbehind = 0
def opengroup(self, name=None):
gid = self.groups
self.groups = gid + 1
@ -352,6 +354,11 @@ def _escape(source, escape, state):
if group < state.groups:
if not state.checkgroup(group):
raise error("cannot refer to open group")
if state.lookbehind:
import warnings
warnings.warn('group references in lookbehind '
'assertions are not supported',
RuntimeWarning)
return GROUPREF, group
raise ValueError
if len(escape) == 2:
@ -630,6 +637,11 @@ def _parse(source, state):
if gid is None:
msg = "unknown group name: {0!r}".format(name)
raise error(msg)
if state.lookbehind:
import warnings
warnings.warn('group references in lookbehind '
'assertions are not supported',
RuntimeWarning)
subpatternappend((GROUPREF, gid))
continue
else:
@ -658,7 +670,10 @@ def _parse(source, state):
raise error("syntax error")
dir = -1 # lookbehind
char = sourceget()
state.lookbehind += 1
p = _parse_sub(source, state)
if dir < 0:
state.lookbehind -= 1
if not sourcematch(")"):
raise error("unbalanced parenthesis")
if char == "=":
@ -689,6 +704,11 @@ def _parse(source, state):
condgroup = int(condname)
except ValueError:
raise error("bad character in group name")
if state.lookbehind:
import warnings
warnings.warn('group references in lookbehind '
'assertions are not supported',
RuntimeWarning)
else:
# flags
if not source.next in FLAGS: