Revert "Use join without default separator"

This reverts commit b0ab8dc0
because it was removing the contents of the message when we
did not have any tag. A test case is also committed.

activesupport/lib/active_support/tagged_logging.rb

@@ -16,7 +16,7 @@ module TaggedLogging
     module Formatter # :nodoc:
       # This method is invoked when a log event occurs
       def call(severity, timestamp, progname, msg)
-        super(severity, timestamp, progname, "#{tags_text} #{msg}".lstrip)
+        super(severity, timestamp, progname, "#{tags_text}#{msg}")
       end
 
       def clear!
@@ -31,7 +31,7 @@ def current_tags
       def tags_text
         tags = current_tags
         if tags.any?
-          tags.collect { |tag| "[#{tag}]" }.join(' ')
+          tags.collect { |tag| "[#{tag}] " }.join
         end
       end
     end

activesupport/test/tagged_logging_test.rb

@@ -29,6 +29,11 @@ def flush(*)
     assert_equal "[BCX] [Jason] [New] Funky time\n", @output.string
   end
 
+  test "does not strip message content" do
+    @logger.info "  Hello"
+    assert_equal "  Hello\n", @output.string
+  end
+
   test "provides access to the logger instance" do
     @logger.tagged("BCX") { |logger| logger.info "Funky time" }
     assert_equal "[BCX] Funky time\n", @output.string