Add regression test for #22471

[jooert]

Closes #22471.

[rust-highfive]

r? @nikomatsakis

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[pnkfelix]

@bors r+ e13d886 rollup

[Manishearth]

The test stil fails. http://buildbot.rust-lang.org/builders/auto-linux-32-opt/builds/4772/steps/test/logs/stdio

[Manishearth]

@bors: r-

[jooert]

I'm sorry I messed up the rollup PR! The weird thing is: When I run

make check-stage1-rpass TESTNAME=issue-22471

locally, the test passes, but it fails when I run

make check-stage1-pretty TESTNAME=issue-22471

However, when I run the exact same command that the test runner claims to compile the test with, compilation works without errors. Compiling with another (nightly f9e53c7 2015-04-24) locally installed version of rustc works fine too. Perhaps there is something I still don't understand about the testing system, but I thought if a test compiles fine using the just compiled rustc and using an older version, too, the test should be good to go.
Nevertheless, even though I don't understand what is failing here, I'm still sorry for the inconvience caused!

[Manishearth]

No problem.

Put an // ignore-pretty on the test, I suspect the literal is getting cropped. (See other tests with the ignore-pretty annotation to figure out how to do it).

[jooert]

Ok, I added the // ignore-pretty. So what is "pretty" supposed to do in comparison to the ordinary "run-pass"?

[Manishearth]

It runs the test through the prettifier (-Z unstable-options --pretty=expanded) and tries it again.

[jooert]

Ah, I see! In this particular case it turns

type Foo<T> where T: Copy = Box<T>;

into

type Foo<T> = Box<T> where T: Copy;

The latter fails with

error: expected one of `+`, `::`, or `;`, found `where`
type Foo<T> = Box<T> where T: Copy;

while the former compiles fine. Isn't that a bug in the prettifier if it transforms working code into non-compiling?

[Manishearth]

Yes, please file it! :)

[jooert]

Ok. 😃
Thank you for your patience and your explanations!

[jooert]

This can be merged now, as #25092 has landed.

[pnkfelix]

@bors r+ c4d8102 rollup

[bors]

⌛ Testing commit c4d8102 with merge 6cd7486...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-x-android-t, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-win-32-nopt-t, auto-win-32-opt, auto-win-64-nopt-t, auto-win-64-opt