Backport #5280: irb crash "begin;retry unless false; end" (plus suggested fix)

• Status: Rejected
• Assignee: yugui (Yuki Sonoda)

[cphoenix (Chris Phoenix)]

If you type "begin;retry unless false; end" into irb 1.9.2, the program prints a nice long error stack (copied below) and exits.

The problem seems to be on line 100 of ~/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb/workspace.rb
in the filter_backtrace function: the backtrace strings are frozen, and line 100 tries to sub! the string:
bt.sub!(/:\s*in `irb_binding'/, '')

But all it does is return the string (or nil) so it shouldn't need to sub in-place.

It looks like simply replacing that line with
bt = bt.sub(/:\s*in `irb_binding'/, '')
would fix the problem.

Here's the trace:

Hobbes-8:cptest cphoenix$ irb
ruby-1.9.2-p180 :001 > begin ; retry unless false; end
SyntaxError: (irb):1: Invalid retry
/Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb/workspace.rb:100:in sub!': can't modify frozen string (RuntimeError) from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb/workspace.rb:100:in filter_backtrace'
from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb.rb:180:in block (3 levels) in eval_input' from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb.rb:179:in each'
from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb.rb:179:in block (2 levels) in eval_input' from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb.rb:273:in signal_status'
from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb.rb:156:in block in eval_input' from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb/ruby-lex.rb:243:in block (2 levels) in each_top_level_statement'
from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in loop' from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in block in each_top_level_statement'
from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in catch' from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in each_top_level_statement'
from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb.rb:155:in eval_input' from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb.rb:70:in block in start'
from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb.rb:69:in catch' from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/irb.rb:69:in start'
from /Users/cphoenix/.rvm/rubies/ruby-1.9.2-p180/bin/irb:16:in `'
Hobbes-8:cptest cphoenix$

And here's the trace after my suggested fix:

Hobbes-8:cptest cphoenix$ irb
ruby-1.9.2-p180 :001 > begin ; retry unless false; end
SyntaxError: (irb):1: Invalid retry
from (irb)
ruby-1.9.2-p180 :002 >

[naruse (Yui NARUSE)]

• Target version deleted (1.9.2)
• Tracker changed from Bug to Backport
• Project changed from Ruby master to Backport192
• Status changed from Open to Assigned
• Assignee set to yugui (Yuki Sonoda)

Please backport r32252

[naruse (Yui NARUSE)]

• Status changed from Assigned to Rejected