Rely on Shellwords.shellescape to escape

spec/spec_helper_acceptance_local.rb

@@ -37,25 +37,5 @@ def postgresql_version
 
 def psql(psql_cmd, user = 'postgres', exit_codes = [0, 1], &block)
   psql = "psql #{psql_cmd}"
-  LitmusHelper.instance.run_shell("cd /tmp; su #{shellescape(user)} -c #{shellescape(psql)}", acceptable_exit_codes: exit_codes, &block)
-end
-
-def shellescape(str)
-  str = str.to_s
-
-  # An empty argument will be skipped, so return empty quotes.
-  return "''" if str.empty?
-
-  str = str.dup
-
-  # Treat multibyte characters as is.  It is caller's responsibility
-  # to encode the string in the right encoding for the shell
-  # environment.
-  str.gsub!(%r{([^A-Za-z0-9_\-.,:/@\n])}, '\\\\\\1')
-
-  # A LF cannot be escaped with a backslash because a backslash + LF
-  # combo is regarded as line continuation and simply ignored.
-  str.gsub!(%r{\n}, "'\n'")
-
-  str
+  LitmusHelper.instance.run_shell("cd /tmp; su #{Shellwords.shellescape(user)} -c #{Shellwords.shellescape(psql)}", acceptable_exit_codes: exit_codes, &block)
 end