mruby expects `malloc(3)` returns `NULL` for too big allocations, so
even if big object allocation (e.g. `[1,2,3]*268888888888888818`)
caused ASAN/Valgrind warnings, it's intentional, and we won't consider
the warning as a security issue.
- Changed the description to match the order of the changed members.
- Replaced "array of symbols" instead of "array of strings that mean symbols".
- The `mrb_kwargs::optional` member has not been present since the first merge. It is a remnant from development time.
- Removed `const` modifier used in variable declarations in examples. This is not always necessary from a user perspective.
- Added note on the use of `MRB_SYM()`.
resolved#5649
I expect this will fix the two problems that "#5640" didn't address.
- It is expected to raise an exception `TypeError`, but it didn't before.
```console
% bin/mruby -e 'p [**1]'
[1]
```
- The variable `h` is expected to keep an empty hash, but it didn't before.
```console
% bin/mruby -e 'h = {}; p(**h, a: 1, b: 2); p h'
{:a=>1, :b=>2}
{:a=>1, :b=>2}
```
## Summary
This following is a behavior from CRuby 1.8.7 to 3.1.0.
```console
% ruby -ve "p ['a', 'b', 'c']*''"
ruby 1.8.7 (2013-12-22 patchlevel 375) [i686-darwin13.0.2]
"abc"
% ruby -ve "p ['a', 'b', 'c']*''"
ruby 3.1.0p0 (2021-12-25 revision fb4df44d16) [x86_64-darwin19]
"abc"
```
### Before (mruby 3.0.0)
mruby unexpectedly gives the TypeError.
```ruby
['a', 'b', 'c']*'' #=> String cannot be converted to Integer (TypeError)
```
### After
This PR makes mruby behave compatible with CRuby.
```ruby
['a', 'b', 'c']*'' #=> 'abc'
```
As far as I checked, the behavior is unspecified when `Array#*`'s argument
is not an instance of Integer class in X 3017 : 2013 (ISO/IEC 30170 : 2012).
## Additional Information
I noticed this difference by the following idiom when writing ASCII art code
using Ruby.
```ruby
%w(foo bar baz)*''
```
e.g. TRICK (https://github.com/tric)
We used to check them by `mrb_ensure_xxx_type()` functions, but type
errors there should not occur if there's no bug in code generations.
So we use assertion rather than dynamic type checks.
The `mrbgems/mruby-errno/src/known_errors_def.cstub` file has been extended, so the `mrbgems/mruby-errno/src/known_errors_e2c.cstub` file is no longer needed.
ref. #2485
The `SystemCallError#to_s` method also needed to be modified, but since it has no functional difference from the `Exception#to_s` method, it will be removed.
Until now, `windows-latest` meant `windows-2019`, but now it seems that it is being replaced by `windows-2022` in stages.
At the same time, Visual Studio 2019 will be replaced by Visual Studio 2022.
Since mruby's CI is configured to assume Visual Studio 2019, we'll update this and explicitly specify `windows-2022`.
Yukihiro "Matz" Matsumoto