Add support for bionic

lib/deb/s3/package.rb

@@ -59,20 +59,31 @@ def extract_control(package)
       if system("which dpkg > /dev/null 2>&1")
         `dpkg -f #{package}`
       else
+	# use ar to determine control file name (control.ext)
+        package_files = `ar t #{package}`
+        control_file = package_files.split("\n").select do |file|
+          file.start_with?("control.")
+        end.first
+        if control_file === "control.tar.gz"
+	  compression = "z"
+	else
+	  compression = "J"
+        end
+
         # ar fails to find the control.tar.gz tarball within the .deb
         # on Mac OS. Try using ar to list the control file, if found,
         # use ar to extract, otherwise attempt with tar which works on OS X.
-        extract_control_tarball_cmd = "ar p #{package} control.tar.gz"
+        extract_control_tarball_cmd = "ar p #{package} #{control_file}"
 
         begin
-          safesystem("ar t #{package} control.tar.gz &> /dev/null")
+          safesystem("ar t #{package} #{control_file} &> /dev/null")
         rescue SafeSystemError
           warn "Failed to find control data in .deb with ar, trying tar."
-          extract_control_tarball_cmd = "tar zxf #{package} --to-stdout control.tar.gz"
+          extract_control_tarball_cmd = "tar #{compression}xf #{package} --to-stdout #{control_file}"
         end
 
         Dir.mktmpdir do |path|
-          safesystem("#{extract_control_tarball_cmd} | tar -zxf - -C #{path}")
+          safesystem("#{extract_control_tarball_cmd} | tar -#{compression}xf - -C #{path}")
           File.read(File.join(path, "control"))
         end
       end