* lisp/progmodes/ruby-mode.el (ruby-operator-re): Consider line

continuation character an operator, as far as indentation is
concerned.

Fixes: debbugs:15369

lisp/ChangeLog

@@ -1,3 +1,9 @@
+2013-09-15  Dmitry Gutov  <dgutov@yandex.ru>
+
+	* progmodes/ruby-mode.el (ruby-operator-re): Consider line
+	continuation character an operator, as far as indentation is
+	concerned (Bug#15369).
+
 2013-09-15  Martin Rudalics  <rudalics@gmx.at>
 
 	* window.el (window--state-put-2): Don't process buffer state

lisp/progmodes/ruby-mode.el

@@ -132,7 +132,7 @@ This should only be called after matching against `ruby-here-doc-beg-re'."
           ruby-block-end-re "\\|}\\|\\]\\)")
   "Regexp to match where the indentation gets shallower.")
 
-(defconst ruby-operator-re "[-,.+*/%&|^~=<>:]"
+(defconst ruby-operator-re "[-,.+*/%&|^~=<>:]\\|\\\\$"
   "Regexp to match operators.")
 
 (defconst ruby-symbol-chars "a-zA-Z0-9_"

test/indent/ruby.rb

@@ -71,3 +71,7 @@ def test2 (arg)
 if something == :==
   do_something
 end
+
+# Bug#15369
+MSG = 'Separate every 3 digits in the integer portion of a number' \
+  'with underscores(_).'