Bug #13925: string.split(pattern, 1) should return [self.dup], but it returns [self]

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.4.2p198 (2017-09-14 revision 59899) [x86_64-darwin16]
• Backport: 2.2: REQUIRED, 2.3: DONE, 2.4: DONE

[tompng (tomoya ishida)]

msg = 'abababababa'
msg.split('b', 4).map(&:upcase!) # won't overwrite msg
puts msg # abababababa (expected)
msg.split('b', 1).map(&:upcase!) # this overwrites msg
puts msg # ABABABABABA (abababababa is expected)

I wrote a patch for this.

[hanachin (Seiei Miyagi)]

• File partition_rpartition.patch partition_rpartition.patch added

There are same problem in partition and rpartition

I expect the s is "abc", but it is modified.

s = "abc"; s.partition("d").map(&:upcase!); s
# => "ABC"

I expect the s is "abc", but it is modified.

s = "abc"; s.rpartition("d").map(&:upcase!); s
# => "ABC"

If string is splitted, partition/rpartition returns the copy of a part of string.

s = "abc"; s.partition("b").map(&:upcase!); s
# => "abc"

s = "abc"; s.rpartition("b").map(&:upcase!); s
# => "abc"

[hanachin (Seiei Miyagi)]

I added some tests and send a Pull Request to ruby/ruby
https://github.com/ruby/ruby/pull/1705

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed
• Backport changed from 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN to 2.2: REQUIRED, 2.3: REQUIRED, 2.4: REQUIRED

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.2: REQUIRED, 2.3: REQUIRED, 2.4: REQUIRED to 2.2: REQUIRED, 2.3: REQUIRED, 2.4: DONE

ruby_2_4 r62667 merged revision(s) 60000,60001,60002.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.2: REQUIRED, 2.3: REQUIRED, 2.4: DONE to 2.2: REQUIRED, 2.3: DONE, 2.4: DONE

ruby_2_3 r62818 merged revision(s) 60000,60001,60002.