Bug #13028: Binding#irb upon exiting makes _ retain the value of the last expression and never change it

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.4.0rc1 (2016-12-12 trunk 57064) [x86_64-darwin15]
• Backport: 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN

[dskecse (Dzianis Dashkevich)]

Given an open irb session. After exiting from binding.irb the _, which is the last value of the current context, somehow retains the value of the last expression evaluated in the context of binding.irb and then doesn't change it. This never happens to the irb subshell in an open irb session.

Steps to reproduce:

1. Fire up irb.
2. Type binding.irb.
3. Get out of the current context by pressing Ctrl-D.
4. Type anything simple like 1+3.
5. Type _ to see 4, receive nil instead.

Another example:

1. Fire up irb.
2. Type binding.irb.
3. Type any expression to evaluate like 1+3.
4. Get out of the current context by pressing Ctrl-D.
5. Type anything simple like 1+4.
6. Type _ to see 5, receive 4 instead.

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Closed

This appears to have been fixed between 2.5 and 2.6:

$ irb25
irb(main):001:0> binding.irb
irb(main):001:0> 1+3
=> 4
irb(main):002:0> exit
=> 0
irb(main):002:0> 1+4
=> 5
irb(main):003:0> _
=> 4

$ irb26
irb(main):001:0> binding.irb
irb(main):001:0> 1+3
=> 4
irb(main):002:0> exit
=> 0
irb(main):002:0> 1+4
=> 5
irb(main):003:0> _
=> 5