1 files changed, 16 insertions, 6 deletions
diff --git a/install.rb b/install.rb
index 03bcfa06b..3d109b9a7 100755
--- a/install.rb
+++ b/install.rb
@@ -286,18 +286,18 @@ def prepare_installation
   if not InstallOptions.destdir.nil?
     destdir = InstallOptions.destdir
   # To be deprecated once people move over to using --destdir option
-  elsif ENV['DESTDIR'] != nil?
+  elsif not ENV['DESTDIR'].nil?
     destdir = ENV['DESTDIR']
     warn "DESTDIR is deprecated. Use --destdir instead."
   else
     destdir = ''
   end
 
-  configdir = "#{destdir}#{configdir}"
-  bindir = "#{destdir}#{bindir}"
-  sbindir = "#{destdir}#{sbindir}"
-  mandir = "#{destdir}#{mandir}"
-  sitelibdir = "#{destdir}#{sitelibdir}"
+  configdir = join(destdir, configdir)
+  bindir = join(destdir, bindir)
+  sbindir = join(destdir, sbindir)
+  mandir = join(destdir, mandir)
+  sitelibdir = join(destdir, sitelibdir)
 
   FileUtils.makedirs(configdir) if InstallOptions.configs
   FileUtils.makedirs(bindir)
@@ -317,6 +317,16 @@ def prepare_installation
 end
 
 ##
+# Join two paths. On Windows, dir must be converted to a relative path,
+# by stripping the drive letter, but only if the basedir is not empty.
+#
+def join(basedir, dir)
+  return "#{basedir}#{dir[2..-1]}" if $operatingsystem == "windows" and basedir.length > 0 and dir.length > 2
+
+  "#{basedir}#{dir}"
+end
+
+##
 # Build the rdoc documentation. Also, try to build the RI documentation.
 #
 def build_rdoc(files)