From 6d6b143d8f4e92c39f6534f7f0362ab471ac2fe0 Mon Sep 17 00:00:00 2001
From: rillig <rillig@pkgsrc.org>
Date: Sat, 18 Apr 2020 12:21:10 +0000
Subject: mk/subst.mk: avoid undefined behavior in regular expressions

https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html
says in section 9.3.2 BRE Ordinary Characters that only very few
characters may be preceded with a backslash.

As a side effect, this change allows parentheses in the variable names
listed in SUBST_VARS (even if that will never happen in practice).

The reason that the regression test had not replaced VAR.[] before was
simply that this variable had not been listed in SUBST_VARS.
---
 mk/subst.mk | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'mk/subst.mk')

diff --git a/mk/subst.mk b/mk/subst.mk
index 099a130a0ba..cd9b769748a 100644
--- a/mk/subst.mk
+++ b/mk/subst.mk
@@ -1,4 +1,4 @@
-# $NetBSD: subst.mk,v 1.76 2020/04/18 11:42:34 rillig Exp $
+# $NetBSD: subst.mk,v 1.77 2020/04/18 12:21:10 rillig Exp $
 #
 # The subst framework replaces text in one or more files in the WRKSRC
 # directory. Packages can define several ``classes'' of replacements.
@@ -128,7 +128,7 @@ SUBST_FILTER_CMD.${class}?=	LC_ALL=C ${SED} ${SUBST_SED.${class}}
 SUBST_VARS.${class}?=		# none
 SUBST_MESSAGE.${class}?=	Substituting "${class}" in ${SUBST_FILES.${class}}
 .  for v in ${SUBST_VARS.${class}}
-SUBST_FILTER_CMD.${class}+=	-e s,@${v:C|[^A-Za-z0-9_]|\\\\&|gW:Q}@,${${v}:S|\\|\\\\|gW:S|,|\\,|gW:S|&|\\\&|gW:S|${.newline}|\\${.newline}|gW:Q},g
+SUBST_FILTER_CMD.${class}+=	-e s,@${v:C|[.[\\*^${$}]|\\\\&|gW:Q}@,${${v}:S|\\|\\\\|gW:S|,|\\,|gW:S|&|\\\&|gW:S|${.newline}|\\${.newline}|gW:Q},g
 .  endfor
 .  if ${SUBST_SHOW_DIFF.${class}:U${SUBST_SHOW_DIFF}:tl} == yes
 _SUBST_KEEP.${class}?=		LC_ALL=C ${DIFF} -u "$$file" "$$tmpfile" || true
-- 
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