From: Szabolcs Nagy <nsz@port70.net>
Date: Sun, 22 Mar 2015 18:32:55 +0000 (+0000)
Subject: do not treat \0 as a backref in BRE
X-Git-Tag: v1.1.8~2
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=32dee9b9b1e557a73cc4427455cd00cb2571436c;p=oweals%2Fmusl.git

do not treat \0 as a backref in BRE

The valid BRE backref tokens are \1 .. \9, and 0 is not a special
character either so \0 is undefined by the standard.

Such undefined escaped characters are treated as literal characters
currently, following existing practice, so \0 is the same as 0.
---

diff --git a/src/regex/regcomp.c b/src/regex/regcomp.c
index 4d80cb1c..dfa9727c 100644
--- a/src/regex/regcomp.c
+++ b/src/regex/regcomp.c
@@ -839,7 +839,7 @@ static reg_errcode_t parse_atom(tre_parse_ctx_t *ctx, const char *s)
 			s--;
 			break;
 		default:
-			if (!ere && isdigit(*s)) {
+			if (!ere && (unsigned)*s-'1' < 9) {
 				/* back reference */
 				int val = *s - '0';
 				node = tre_ast_new_literal(ctx->mem, BACKREF, val, ctx->position);