* lisp/progmodes/ruby-mode.el (ruby-syntax-propertize):
Make sure to backtrack if the "symbols with special characters"
rule is aborted because of preceding colon.
* lisp/progmodes/ruby-mode.el (ruby-syntax-propertize):
Add a rule for setter symbols (bug#42846).
(ruby-font-lock-keywords): Remove dead code, left over from before
commit 26f9c507.
* lisp/progmodes/ruby-mode.el (ruby-smie--bosp):
Handle '=' being part of a symbol (bug#42846).
* test/lisp/progmodes/ruby-mode-resources/ruby.rb:
Add corresponding indentation examples.