install-sh upgrade from Automake

[Paul Eggert]

I installed this, in preparation for further patches in this area
prompted by Bruno Haible's mkdir -p proposal.

2006-05-10  Paul Eggert  <address@hidden>

        * config/install-sh: Update to Automake CVS version, as follows:

        2006-04-25  Stepan Kasal  <address@hidden>
        * lib/install-sh: Simplify the expr implementation of dirname.
        2006-04-24  Paul Eggert  <address@hidden>
        * lib/install-sh: Handle --, and diagnose unknown options.

--- config/install-sh   6 Apr 2006 22:40:55 -0000       1.11
+++ config/install-sh   10 May 2006 19:16:41 -0000
@@ -1,7 +1,7 @@
 #!/bin/sh
 # install - install a program, script, or datafile
 
-scriptversion=2006-01-12.21
+scriptversion=2006-04-25.22
 
 # This originates from X11R5 (mit/util/scripts/install.sh), which was
 # later released in X11R6 (xc/config/util/install.sh) with the
@@ -109,7 +109,7 @@ Environment variables override the defau
   CHGRPPROG CHMODPROG CHOWNPROG CPPROG MKDIRPROG MVPROG RMPROG STRIPPROG
 "
 
-while test -n "$1"; do
+while test $# -ne 0; do
   case $1 in
     -c) shift
         continue;;
@@ -150,25 +150,33 @@ while test -n "$1"; do
 
     --version) echo "$0 $scriptversion"; exit $?;;
 
-    *)  # When -d is used, all remaining arguments are directories to create.
-       # When -t is used, the destination is already specified.
-       test -n "$dir_arg$dstarg" && break
-        # Otherwise, the last argument is the destination.  Remove it from 
address@hidden
-       for arg
-       do
-          if test -n "$dstarg"; then
-           # $@ is not empty: it contains at least $arg.
-           set fnord "$@" "$dstarg"
-           shift # fnord
-         fi
-         shift # arg
-         dstarg=$arg
-       done
+    --)        shift
        break;;
+
+    -*)        echo "$0: invalid option: $1" >&2
+       exit 1;;
+
+    *)  break;;
   esac
 done
 
-if test -z "$1"; then
+if test $# -ne 0 && test -z "$dir_arg$dstarg"; then
+  # When -d is used, all remaining arguments are directories to create.
+  # When -t is used, the destination is already specified.
+  # Otherwise, the last argument is the destination.  Remove it from 
address@hidden
+  for arg
+  do
+    if test -n "$dstarg"; then
+      # $@ is not empty: it contains at least $arg.
+      set fnord "$@" "$dstarg"
+      shift # fnord
+    fi
+    shift # arg
+    dstarg=$arg
+  done
+fi
+
+if test $# -eq 0; then
   if test -z "$dir_arg"; then
     echo "$0: no input file specified." >&2
     exit 1
@@ -230,8 +238,7 @@ do
        expr X"$dst" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
             X"$dst" : 'X\(//\)[^/]' \| \
             X"$dst" : 'X\(//\)$' \| \
-            X"$dst" : 'X\(/\)' \| \
-            .       : '\(.\)' 2>/dev/null ||
+            X"$dst" : 'X\(/\)' \| . 2>/dev/null ||
        echo X"$dst" |
            sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
                   s//\1/