Rewrite bsort() from hand-rolled recursive to simpler iterative reusing code

ksh(1) can sort itself and addel() ensures uniqueness, so reuse both to get
a much simpler shell version of `sort -u' that is bug-for-bug compatible
with the old one but shorter and easier to tweak/reason about.

OK afresh1

diff --git a/distrib/miniroot/install.sub b/distrib/miniroot/install.sub
index a085839..7d445b7 100644 (file)
--- a/distrib/miniroot/install.sub
+++ b/distrib/miniroot/install.sub
@@ -1,5 +1,5 @@
 #!/bin/ksh
-#      $OpenBSD: install.sub,v 1.1227 2023/02/09 10:38:41 kn Exp $
+#      $OpenBSD: install.sub,v 1.1228 2023/02/16 18:10:28 kn Exp $
 #
 # Copyright (c) 1997-2015 Todd Miller, Theo de Raadt, Ken Westerback
 # Copyright (c) 2015, Robert Peichaer <rpe@openbsd.org>
@@ -109,28 +109,6 @@ wait_cgiinfo() {
 # Utils functions
 # ------------------------------------------------------------------------------
 
-# Sort and print unique list of provided arguments.
-bsort() {
-       local _a=$1 _b _l
-
-       (($#)) && shift || return
-
-       for _b; do
-               [[ $_a == "$_b" ]] && continue
-               if [[ $_a > $_b ]]; then
-                       _l="$_a $_l" _a=$_b
-               else
-                       _l="$_b $_l"
-               fi
-       done
-
-       # Output the smallest value found.
-       (($#)) && echo -n "$_a " || echo -n "$_a"
-
-       # Sort remaining values.
-       bsort $_l
-}
-
 # Test the first argument against the remaining ones, return success on a match.
 isin() {
        local _a=$1 _b
@@ -163,6 +141,17 @@ rmel() {
        echo -n "$_c"
 }
 
+# Sort and print unique list of provided arguments.
+bsort() {
+       local _a _l
+
+       set -s -- $@
+       for _a; do
+               _l=$(addel $_a $_l)
+       done
+       echo -n $_l
+}
+
 # If possible, print the timestamp received from the ftplist.cgi output,
 # adjusted with the time elapsed since it was received.
 http_time() {