Bug #5752: Array#delete_if side effects due to changeset r32360

• Status: Closed
• Priority: Normal
• Assignee: -
• Target version: 1.9.3
• ruby -v: ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]
• Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN

[gettalong (Thomas Leitner)]

It seems that the changeset r32360 introduced another side effect. Here are two IRB sessions, one in ruby-1.9.2-p136 and the other in ruby-1.9.3-p0:

ruby-1.9.2-p136 :001 > x = [1,2,3,4,5,6,7,8,9]
=> [1, 2, 3, 4, 5, 6, 7, 8, 9]
ruby-1.9.2-p136 :002 > x.delete_if {|i| i == x[i-1]}
=> []

ruby-1.9.3-p0 :001 > x = [1,2,3,4,5,6,7,8,9]
=> [1, 2, 3, 4, 5, 6, 7, 8, 9]
ruby-1.9.3-p0 :002 > x.delete_if {|i| i == x[i-1]}
=> [2, 3, 4, 5, 6, 7, 8, 9]

If this is indeed the intended behaviour, it should probably be documented clearly that the array is changed instantly every time the block is called and not after the iteration is over.

[funny_falcon (Yura Sokolov)]

Actually, it were next changeset r32373

[funny_falcon (Yura Sokolov)]

• File array.c.patch array.c.patch added

[nobu (Nobuyoshi Nakada)]

• Category changed from core to doc
• Status changed from Open to Closed

[akr (Akira Tanaka)]

• Related to Feature #10714: Array#reject! nonlinear performance problem added