[#106341] [Ruby master Bug#18369] users.detect(:name, "Dorian") as shorthand for users.detect { |user| user.name == "Dorian" } — dorianmariefr <noreply@...>
Issue #18369 has been reported by dorianmariefr (Dorian Mari辿).
14 messages
2021/11/30
[#106351] [Ruby master Bug#18371] Release branches (release information in general) — "tenderlovemaking (Aaron Patterson)" <noreply@...>
Issue #18371 has been reported by tenderlovemaking (Aaron Patterson).
7 messages
2021/11/30
[ruby-core:106350] [Ruby master Feature#18367] Stop the interpreter from escaping error messages
From:
"Dan0042 (Daniel DeLorme)" <noreply@...>
Date:
2021-11-30 19:07:26 UTC
List:
ruby-core #106350
Issue #18367 has been updated by Dan0042 (Daniel DeLorme).
How is this supposed to interact with the default highlighting?
-e:1:in `<main>': **\e[31mRed\e[0m error (_RuntimeError_)**
If the ANSI escape codes are not escaped, the `\e[0m` would reset the formatting early and it would look like
-e:1:in `<main>': **Red** error (**_RuntimeError_)** *(with colored "Red")*
I'm not sure it makes sense to allow ANSI escapes that can _only_ result in broken formatting.
What about just removing the backslash from the set of escaped characters? For most errors it can be misleading, as in the example of `"\\".no_method` above.
----------------------------------------
Feature #18367: Stop the interpreter from escaping error messages
https://bugs.ruby-lang.org/issues/18367#change-94990
* Author: mame (Yusuke Endoh)
* Status: Open
* Priority: Normal
----------------------------------------
## Proposal
At the present time, the Ruby interpreter escapes some characters (*1) in error messages when an uncaught error is printed. I'd like to propose stopping this escaping behavior.
```
class MyError < StandardError
def message
"foo\\bar"
end
end
raise MyError
#=> current: test.rb:7: in `<main>': foo\\bar (MyError)
#=> excepted: test.rb:7: in `<main>': foo\bar (MyError)
```
*1: Escaped characters are any control characters except `\r` and `\n`, and a backslash `\\`.
## Motivation
This behavior prevents us from adding an attribution (color, underline, etc.) to the error message because it escapes escape sequences. Nowadays, such a rich presentation of terminal output is more and more important.
```
$ ruby -e 'raise "\e[31mRed\x1b[0m error"'
-e:1:in `<main>': \e[31mRed\x1b[0m error (RuntimeError)
```
Also, the behavior in question leads to rather confusing error printing. See the error output of `"\\".no_method`:
```
$ ruby -e '"\\".no_method'
-e:1:in `<main>': undefined method `no_method' for "\\\\":String (NoMethodError)
"\\\\".no_method
^^^^^^^^^^
```
The two occurrences of `"\\\\"` must be `"\\"`. Worse, the output of error_highlight `^^^^` points wrong position.
Note that this issue is never specific to error_highlight. The receiver of NoMethodError, `"\\\\":String`, is also wrongly escaped. It must be `"\\":String`.
## Why the escaping behavior was introduced
AFAIK, the behavior was introduced because of a security concern. It is considered harmful for an attacker to be able to print arbitrary escape sequences to victim's terminal. (See [this article](https://marc.info/?l=bugtraq&m=104612710031920&w=2) in detail.)
However, I believe it is rare to see the error logs of an application that may be exposed to attacks (i.e. in production mode) in a terminal, as the error output of the Ruby interpreter.
Even if that is the case, I think such escaping should be done as a responsibility of the application, and not implicitly by the interpreter. I briefly surveyed other major languages than Ruby, and I could find no language that escapes error messages. This is the transcript of Python and Node.js.
```
$ python3 -c 'raise Exception("\x1b[31mRed\x1b[0m error")'
Traceback (most recent call last):
File "<string>", line 1, in <module>
Exception: Red error
$ node -e 'throw("\x1b[31mRed\x1b[0m error")'
[eval]:1
throw("\x1b[31mRed\x1b[0m error")
^
Red error
(Use `node --trace-uncaught ...` to show where the exception was thrown)
```
Just in case, I reported these behaviors to the security contacts of Python and Node.js, and both responded to me that this is not a securty issue. I think their decisions are quite reasonable.
## Migration
It would be a good idea to first make the following behavior as a migration path.
* When an error message does not include a control character, no escaping is applied.
* When an error message does include a control character, "Warning: this error message is currently escaped because it includes a control character(s), but this will not be escaped in Ruby 3.X" is printed, and the escaping is applied.
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