mozilla/rust — pull request #8350 by dim-an (2013-08-06 20:32:18+00:00)
Title: Fix bug in `match`ing struct patterns

Code that collects fields in struct-like patterns used to ignore
wildcard patterns like `Foo{_}`. But `enter_defaults` considered
struct-like patterns as default in order to overcome this
(accoring to my understanding of situation).

However such behaviour caused code like this:
```
enum E {
Foo{f: int},
Bar
}
let e = Bar;
match e {
Foo{f: _f} => { /* do something (1) */ }
_ => { /* do something (2) */ }
}
```
consider pattern `Foo{f: _f}` as default. That caused inproper behaviour
and even segfaults while trying to destruct `Bar` as `Foo{f: _f}`.
Issues: #5625 , #5530.

This patch fixes `collect_record_or_struct_fields` to split cases of
single wildcard struct-like pattern and no struct-like pattern at all.
Former case resolved with `enter_rec_or_struct` (and not with
`enter_defaults`).

Closes #5625.
Closes #5530.