Backport #146: Incorrect line numbers in "caller" output when evaluated in a Proc binding

• Status: Closed
• Assignee: matz (Yukihiro Matsumoto)

[wilson (Wilson Bilkovich)]

=begin
The second frame's line number appears to always be incorrect when a Proc is created via a non-toplevel method call.
This small program and its output illustrate the issue:

def first # line 1 of proc_caller.rb on my system
second
end

def second
b = third do
1 + 1
end
return b
end

def third(&b)
return b
end

eval("p caller(0)", first)

Output on recent 1.8 releases, including 1.8.6 and 1.8.7:
["proc_caller.rb:6:in second'", "proc_caller.rb:6:in first'", "proc_caller.rb:16"]

Output that I would expect: (line 6 is in 'second', not 'first')
["proc_caller.rb:6:in second'", "proc_caller.rb:2:in first'", "proc_caller.rb:16"]
=end

[wilson (Wilson Bilkovich)]

=begin
Everybody agrees that this is a bug, right?
=end

[shyouhei (Shyouhei Urabe)]

• Assignee set to matz (Yukihiro Matsumoto)

=begin

=end

[runpaint (Run Paint Run Run)]

=begin
On 1.9 trunk:

 ["(eval):1:in `second'", "/tmp/proc_caller.rb:16:in `eval'", "/tmp/proc_caller.rb:16:in `<main>'"]

(I'm trying to understand the changes in caller output between 1.8 and 1.9 and failing).
=end

[marcandre (Marc-Andre Lafortune)]

• Category set to core
• ruby -v set to -

=begin
The expected output should be the same for
eval("p caller(0)", first.binding)
and
eval("p caller(0)", second.binding)
since the block has the same binding (i.e. that of second).

At the moment "p caller" is evaluated, both first and second have returned, so the output should not contain "proc_caller.rb:6". In neither case should we expect to see "proc_caller.rb:2:in `first'" in the backtrace.

It appears that when a block is captured (here by third), the binding is set the the full stack instead of just that of second. This leads to a longer backtrace, as seen with the output of caller or if an exception is raised in the eval.

Just to confirm that this bug is not present in Ruby 1.9; the output is quite sensible and the same from both first.binding and second.binding.
=end

[shyouhei (Shyouhei Urabe)]

• Status changed from Open to Assigned

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[jeremyevans0 (Jeremy Evans)]

• Tracker changed from Bug to Backport
• Project changed from Ruby 1.8 to Backport187
• Description updated (diff)
• Status changed from Assigned to Closed
• ruby -v deleted (-)