[INSTALLED 2/3] install-sh: do not assume / = //

* lib/install-sh: Do not append / to destination
directory if it already ends in /.  This supports
a destination directory of // on hosts where / and //
are distinct directories, as POSIX allows.
---
 lib/install-sh | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/lib/install-sh b/lib/install-sh
index 0360b79e7..ac159ceda 100755
--- a/lib/install-sh
+++ b/lib/install-sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 # install - install a program, script, or datafile
 
-scriptversion=2016-01-11.22; # UTC
+scriptversion=2017-09-23.17; # UTC
 
 # This originates from X11R5 (mit/util/scripts/install.sh), which was
 # later released in X11R6 (xc/config/util/install.sh) with the
@@ -271,15 +271,18 @@ do
     fi
     dst=$dst_arg
 
-    # If destination is a directory, append the input filename; won't work
-    # if double slashes aren't ignored.
+    # If destination is a directory, append the input filename.
     if test -d "$dst"; then
       if test "$is_target_a_directory" = never; then
         echo "$0: $dst_arg: Is a directory" >&2
         exit 1
       fi
       dstdir=$dst
-      dst=$dstdir/`basename "$src"`
+      dstbase=`basename "$src"`
+      case $dst in
+	*/) dst=$dst$dstbase;;
+	*)  dst=$dst/$dstbase;;
+      esac
       dstdir_status=0
     else
       dstdir=`dirname "$dst"`
@@ -288,6 +291,11 @@ do
     fi
   fi
 
+  case $dstdir in
+    */) dstdirslash=$dstdir;;
+    *)  dstdirslash=$dstdir/;;
+  esac
+
   obsolete_mkdir_used=false
 
   if test $dstdir_status != 0; then
@@ -427,8 +435,8 @@ do
   else
 
     # Make a couple of temp file names in the proper directory.
-    dsttmp=$dstdir/_inst.$$_
-    rmtmp=$dstdir/_rm.$$_
+    dsttmp=${dstdirslash}_inst.$$_
+    rmtmp=${dstdirslash}_rm.$$_
 
     # Trap to clean up those temp files at exit.
     trap 'ret=$?; rm -f "$dsttmp" "$rmtmp" && exit $ret' 0
-- 
2.13.5