Fixes [Feature #13381]
When passed a `fake_str`, `register_fstring` would create new strings
with `str_new_static`. That's not what was expected, and answer
almost no use cases.
since 58325daae3.
../string.c:1339:1: warning: ‘str_new_empty’ defined but not used [-Wunused-function]
1339 | str_new_empty(VALUE str)
| ^~~~~~~~~~~~~
This modifies the following String methods to return String instances
instead of subclass instances:
* String#*
* String#capitalize
* String#center
* String#chomp
* String#chop
* String#delete
* String#delete_prefix
* String#delete_suffix
* String#downcase
* String#dump
* String#each/#each_line
* String#gsub
* String#ljust
* String#lstrip
* String#partition
* String#reverse
* String#rjust
* String#rpartition
* String#rstrip
* String#scrub
* String#slice!
* String#slice/#[]
* String#split
* String#squeeze
* String#strip
* String#sub
* String#succ/#next
* String#swapcase
* String#tr
* String#tr_s
* String#upcase
This also fixes a bug in String#swapcase where it would return the
receiver instead of a copy of the receiver if the receiver was the
empty string.
Some string methods were left to return subclass instances:
* String#+@
* String#-@
Both of these methods will return the receiver (subclass instance)
in some cases, so it is best to keep the returned class consistent.
Fixes [#10845]
`encoding` can be not only an encoding name, but also an Encoding object.
```
s = String.new('foo', encoding: Encoding::US_ASCII)
s.encoding # => #<Encoding:US-ASCII>
```
When the pattern Regexp given to String#index and String#rindex
contain a /\K/ (lookbehind) operator, these methods return the
position where the beginning of the lookbehind pattern matches, while
they are expected to return the position where the \K matches.
```
# without patch
"abcdbce".index(/b\Kc/) # => 1
"abcdbce".rindex(/b\Kc/) # => 4
```
This patch fixes this problem by using BEG(0) instead of the return
value of rb_reg_search.
```
# with patch
"abcdbce".index(/b\Kc/) # => 2
"abcdbce".rindex(/b\Kc/) # => 5
```
Fixes [Bug #17118]
When the pattern given to String#partition and String#rpartition
contain a /\K/ (lookbehind) operator, the methods return strings
sliced at incorrect positions.
```
# without patch
"abcdbce".partition(/b\Kc/) # => ["a", "c", "cdbce"]
"abcdbce".rpartition(/b\Kc/) # => ["abcd", "c", "ce"]
```
This patch fixes the problem by using BEG(0) instead of the return
value of rb_reg_search.
```
# with patch
"abcdbce".partition(/b\Kc/) # => ["ab", "c", "dbce"]
"abcdbce".rpartition(/b\Kc/) # => ["abcdb", "c", "e"]
```
As a side-effect this patch makes String#partition 2x faster when the
pattern is a costly Regexp by performing Regexp search only once,
which was unexpectedly done twice in the original implementation.
Fixes [Bug #17119]
Use BEG(0) instead of the result of rb_reg_search to handle the cases
when the separator Regexp contains /\K/ (lookbehind) operator.
Fixes [Bug #17113]
Not every compilers understand that rb_raise does not return. When a
function does not end with a return statement, such compilers can issue
warnings. We would better tell them about reachabilities.
Koichi Sasada
Jean Boussier
Nobuyoshi Nakada
Takashi Kokubun
Jeremy Evans
Alan Wu
Stefan Stüben
Burdette Lamar
Kazuhiro NISHIYAMA
Soutaro Matsumoto
Kasumi Hanazuki
卜部昌平
S-H-GAMELINKS