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[PATCH 2/2] Diagnose ERE '()|\1'
From: |
Paul Eggert |
Subject: |
[PATCH 2/2] Diagnose ERE '()|\1' |
Date: |
Sat, 19 Sep 2015 13:55:12 -0700 |
Problem reported by Hanno Böck in: http://bugs.gnu.org/21513
* lib/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'.
---
ChangeLog | 8 ++++++++
lib/regcomp.c | 4 ++++
2 files changed, 12 insertions(+)
diff --git a/ChangeLog b/ChangeLog
index f846aac..7c83566 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
2015-09-19 Paul Eggert <address@hidden>
+ Diagnose ERE '()|\1'
+ Problem reported by Hanno Böck in: http://bugs.gnu.org/21513
+ * lib/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'.
+
regex: merge patches from libc
2015-09-08 Joseph Myers <address@hidden>
diff --git a/lib/regcomp.c b/lib/regcomp.c
index f50afb4..4cbb1b2 100644
--- a/lib/regcomp.c
+++ b/lib/regcomp.c
@@ -2191,6 +2191,7 @@ parse_reg_exp (re_string_t *regexp, regex_t *preg,
re_token_t *token,
{
re_dfa_t *dfa = 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;
@@ -2201,6 +2202,8 @@ 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))
{
@@ -2208,6 +2211,7 @@ 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;
--
2.1.0