Hi!

I just noticed that Ruby mode can go into infinite recursion (or "Lisp
nesting exceeds ‘max-lisp-eval-depth’"). I managed to boil it down to the
following:

    Evaluate (setq debug-on-error t)

    Open a new file, say test.rb
    Type:

        func do {

    And press return.

In the backtrace, the following is listed over and over again:

  ruby-smie--indent-to-stmt()
  ruby-smie-rules(:before "{")
  smie-indent--rule-1(:before "{" nil nil)
  smie-indent--rule(:before "{")
  smie-indent-keyword()
  run-hook-with-args-until-success(smie-indent-keyword)
  smie-indent-calculate()
  smie-indent-virtual()

It happens in Emacs 25.2 and in a week-old build from the master branch.

Sincerely,
    Anders Lindgren

In GNU Emacs 27.0.50 (build 2, x86_64-apple-darwin16.6.0, NS appkit-1504.83
Version 10.12.5 (Build 16F73))
 of 2017-10-25 built on mbp.lan
Repository revision: bc9300ac5ed3bdf52a2f8b9e217236e1ee76cd02
Windowing system distributor 'Apple', version 10.3.1504
Recent messages:
t
(New file)
Mark set
s-( is undefined
Mark set
Entering debugger...
Error in debug printer: (void-function t) [1113 times]
Error during redisplay: (ucs-normalize-hfs-nfd-pre-write-conversion 1 92)
signaled (error "Variable binding depth exceeds max-specpdl-size") [2 times]
set-auto-coding: Variable binding depth exceeds max-specpdl-size
Back to top level

Configured features:
JPEG NOTIFY ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS NS

Important settings:
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  value of $LANG: en_SE.UTF-8
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Major mode: Special

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Load-path shadows:
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Features:
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Memory information:
((conses 16 209217 10912)
 (symbols 48 20615 1)
 (miscs 40 57 249)
 (strings 32 30746 1897)
 (string-bytes 1 808845)
 (vectors 16 35813)
 (vector-slots 8 721700 15012)
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 (intervals 56 218 0)
 (buffers 992 14))