[ruby-core:116935] [Ruby master Bug#18743] Enumerator#next / peek re-use each others stacktraces

Issue #18743 has been updated by nagachika (Tomoyuki Chikanaga).

Backport changed from 3.0: REQUIRED, 3.1: REQUIRED, 3.2: REQUIRED to 3.0: R=
EQUIRED, 3.1: REQUIRED, 3.2: DONE

ruby_3_2 5e4606423da96c2e26b00981c22bddfce0d970bf merged revision(s) f15123=
c34ce80f3928612befe2a9aaf4c9d27fda.

----------------------------------------
Bug #18743: Enumerator#next / peek re-use each others stacktraces
https://bugs.ruby-lang.org/issues/18743#change-106970

* Author: sos4nt (Stefan Sch=FC=DFler)
* Status: Closed
* Assignee: ko1 (Koichi Sasada)
* Backport: 3.0: REQUIRED, 3.1: REQUIRED, 3.2: DONE
----------------------------------------
I encountered an odd behavior.

If I rescue the `StopIteration` exception from `peek` and call `next` after=
wards: (or vice-versa)

```ruby
# enum.rb             # 1
                      # 2
enum =3D [].each        # 3
enum.peek rescue nil  # 4
enum.next             # 5
```

it will show the stacktrace from the rescued `peek` call:

```
$ ruby enum.rb
enum.rb:4:in `peek': iteration reached an end (StopIteration)
	from enum.rb:4:in `<main>'
```

Whereas the error should refer to `next` on line number 5.

The same happens when calling `peek` after `next` or when having muliple `p=
eek` / `next` calls:

```ruby
# enum.rb                # 1
                         # 2
enum =3D [].each           # 3
enum.peek rescue nil     # 4
enum.next rescue nil     # 5
enum.peek rescue nil     # 6
puts "line #{__LINE__}"  # 7
enum.next                # 8
```

The stacktrace from the first (rescued) `peek` or `next` call will be shown=
 which doesn't reflect the actual error location:

```
$ ruby enum.rb
line 7
enum.rb:4:in `peek': iteration reached an end (StopIteration)
	from enum.rb:4:in `<main>'
```

This is very confusing when debugging code.

---Files--------------------------------
01-Recreate-stacktrace-enumerator.patch (1.29 KB)


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