Bug #13621: String#split returns an array longer than given limit, when passing a regexp with groups

• Status: Closed
• Assignee: stomar (Marcus Stollsteimer)
• Target version: -
• Backport: 2.2: WONTFIX, 2.3: DONE, 2.4: DONE

[cichol (Renxiang Cai)]

The String#split documentation(http://ruby-doc.org/core-2.4.1/String.html#method-i-split) described:

If pattern is a Regexp, str is divided where the pattern matches. Whenever the pattern matches a zero-length string, str is split into individual characters. If pattern contains groups, the respective matches will be returned in the array as well.

If limit is a positive number, at most that number of fields will be returned (if limit is 1, the entire string is returned as the only entry in an array).

However giving a regexp with groups, split can return fields more than a given limit:

'aBa'.split(/(B)()()/, 2) # => ["a", "B", "", "", "a"]

Shouldn't it be ["a", "B"] ?

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Assigned
• Assignee set to stomar (Marcus Stollsteimer)

A documentation issue.
the limit limits only split fields, not separators.

[stomar (Marcus Stollsteimer)]

• Status changed from Assigned to Closed

Applied in changeset trunk|r59002.

---

string.c: docs for String#split

• string.c: [DOC] clarify docs for String#split when called
  with limit and capture groups.
  Reported by Cichol Tsai. [ruby-core:81505] [Bug #13621]

[stomar (Marcus Stollsteimer)]

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

[stomar (Marcus Stollsteimer)]

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

[usa (Usaku NAKAMURA)]

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

ruby_2_3 r59227 merged revision(s) 59002.

[nagachika (Tomoyuki Chikanaga)]

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

ruby_2_4 r59403 merged revision(s) 59002.