From 4781b072014e7150afefddb88a05a210a88b486e Mon Sep 17 00:00:00 2001
From: Fredrik Lundh <fredrik@pythonware.com>
Date: Thu, 29 Jun 2000 12:38:45 +0000
Subject: [PATCH] - make sure group names are valid identifiers (closes the
"SRE: symbolic reference" bug)
---
Lib/sre_parse.py | 30 +++++++++++++++++++++++++-----
1 file changed, 25 insertions(+), 5 deletions(-)
diff --git a/Lib/sre_parse.py b/Lib/sre_parse.py
index 9f5386e346..8ab36c8698 100644
--- a/Lib/sre_parse.py
+++ b/Lib/sre_parse.py
@@ -168,6 +168,24 @@ class Tokenizer:
self.next = self.__next()
return this
+def isident(char):
+ return "a" <= char <= "z" or "A" <= char <= "Z" or char == "_"
+
+def isdigit(char):
+ return "0" <= char <= "9"
+
+def isname(name):
+ # check that group name is a valid string
+ # FIXME: <fl> this code is really lame. should use a regular
+ # expression instead, but I seem to have certain bootstrapping
+ # problems here ;-)
+ if not isident(name[0]):
+ return 0
+ for char in name:
+ if not isident(char) and not isdigit(char):
+ return 0
+ return 1
+
def _group(escape, state):
# check if the escape string represents a valid group
try:
@@ -418,9 +436,10 @@ def _parse(source, state, flags=0):
raise error, "unterminated name"
if char == ">":
break
- # FIXME: check for valid character
name = name + char
group = 1
+ if not isname(name):
+ raise error, "illegal character in group name"
elif source.match("="):
# named backreference
raise error, "not yet implemented"
@@ -522,20 +541,21 @@ def parse_template(source, pattern):
while 1:
char = s.get()
if char is None:
- raise error, "unterminated index"
+ raise error, "unterminated group name"
if char == ">":
break
- # FIXME: check for valid character
name = name + char
if not name:
- raise error, "bad index"
+ raise error, "bad group name"
try:
index = int(name)
except ValueError:
+ if not isname(name):
+ raise error, "illegal character in group name"
try:
index = pattern.groupindex[name]
except KeyError:
- raise IndexError, "unknown index"
+ raise IndexError, "unknown group name"
a((MARK, index))
elif len(this) > 1 and this[1] in DIGITS:
while s.next in DIGITS:
--
2.50.1