From ec3628d8dbd4d112033b4ca79c296ad570222a22 Mon Sep 17 00:00:00 2001
Message-Id: <ec3628d8dbd4d112033b4ca79c296ad570222a22.1715038390.git.mdw@distorted.org.uk>
From: Mark Wooding <mdw@chiark.greenend.org.uk>
Date: Thu, 20 Sep 2012 00:59:16 +0100
Subject: [PATCH] keyfunc.sh.in: Make sure we can match the `0' string.
Organization: Straylight/Edgeware

From: Mark Wooding <mdw@distorted.org.uk>

The expr(1) tool exits with status 1 if its output is zero.  The `:'
operator evaluates to the substring matched by the outermost parentheses
in the pattern, if there are any.  Therefore, matching `0' against the
`R_NUMERIC' pattern always appears to fail.  Fix this and similar problems
by adding extra parens around the entire pattern, including the leading
sentinel `Q'.
---
 keyfunc.sh.in | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/keyfunc.sh.in b/keyfunc.sh.in
index 98354d1..31843bf 100644
--- a/keyfunc.sh.in
+++ b/keyfunc.sh.in
@@ -154,8 +154,14 @@ check () {
 
   validp=t
   case "$thing" in
-    *"$nl"*) validp=nil ;;
-    *) if ! expr >/dev/null "Q$thing" : "Q$ckpat\$"; then validp=nil; fi ;;
+    *"$nl"*)
+      validp=nil
+      ;;
+    *)
+      if ! expr >/dev/null "Q$thing" : "\(Q$ckpat\)\$"; then
+      validp=nil
+      fi
+      ;;
   esac
   case $validp in
     nil) echo >&2 "$quis: bad $ckwhat \`$thing'"; exit 1 ;;
-- 
[mdw]