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[PATCH 15/17] Regex: Diagnose ERE "()|\1".
- From: Arnold Robbins <arnold at skeeve dot com>
- To: carlos at redhat dot com, libc-alpha at sourceware dot org
- Date: Fri, 08 Dec 2017 11:19:24 +0200
- Subject: [PATCH 15/17] Regex: Diagnose ERE "()|\1".
- Authentication-results: sourceware.org; auth=none
This patch fixes a bug related to diagnosing ERE '()|\1'. See
http://bugs.gnu.org/21513. I pulled this in from GNULIB.
2017-11-30 Paul Eggert <eggert@cs.ucla.edu>
Diagnose ERE '()|\1'
Problem reported by Hanno Boeck in: http://bugs.gnu.org/21513
* posix/regcomp.c (parse_reg_exp): While parsing alternatives, keep
track of the set of previously-completed subexpressions available
before the first alternative, and restore this set just before
parsing each subsequent alternative. This lets us diagnose the
invalid back-reference in the ERE '()|\1'.
diff --git a/posix/regcomp.c b/posix/regcomp.c
index 8920cf1..e63c258 100644
--- a/posix/regcomp.c
+++ b/posix/regcomp.c
@@ -2157,6 +2157,7 @@ parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
{
re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
bin_tree_t *tree, *branch = NULL;
+ bitset_word_t initial_bkref_map = dfa->completed_bkref_map;
tree = parse_branch (regexp, preg, token, syntax, nest, err);
if (BE (*err != REG_NOERROR && tree == NULL, 0))
return NULL;
@@ -2167,6 +2168,8 @@ parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
if (token->type != OP_ALT && token->type != END_OF_RE
&& (nest == 0 || token->type != OP_CLOSE_SUBEXP))
{
+ bitset_word_t accumulated_bkref_map = dfa->completed_bkref_map;
+ dfa->completed_bkref_map = initial_bkref_map;
branch = parse_branch (regexp, preg, token, syntax, nest, err);
if (BE (*err != REG_NOERROR && branch == NULL, 0))
{
@@ -2174,6 +2177,7 @@ parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
postorder (tree, free_tree, NULL);
return NULL;
}
+ dfa->completed_bkref_map |= accumulated_bkref_map;
}
else
branch = NULL;