ICE on malformed function signature (ident only path)

[nwin]

This minimal example lets the compiler crash:

fn bug(Type<T>, arg: Type);

this doesn’t happen with the following code:

fn bug(Type, arg: Type);

trace:

test.rs:1:8: 1:12 error: internal compiler error: ident only path should have been covered already
test.rs:1 fn bug(Type<T>, arg: Type);
                 ^~~~
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'Box<Any>', /Users/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-mac/build/src/libsyntax/diagnostic.rs:129

stack backtrace:
   1:        0x112422be3 - sys::backtrace::write::hc8e3cee73e646c590nC
   2:        0x112450be5 - panicking::on_panic::h00b47941f5bc8a02HOL
   3:        0x11237a418 - rt::unwind::begin_unwind_inner::h539538ef7f909326UvL
   4:        0x111a38dcf - rt::unwind::begin_unwind::h17340398235865146743
   5:        0x111a38d7c - diagnostic::SpanHandler::span_bug::hef0e2599b36810bavYE
   6:        0x111a61b15 - parse::parser::Parser<'a>::parse_pat::hb3cc0e8f43f24f14wLL
   7:        0x111a56394 - parse::parser::Parser<'a>::parse_arg_general::h5a55ff7b6be1da0384J
   8:        0x111a831c9 - parse::parser::Parser<'a>::parse_seq_to_before_end::h11152631335872661402
   9:        0x111a550a8 - parse::parser::Parser<'a>::parse_fn_args::hd367de6c06911261yAM
  10:        0x111a8370d - parse::parser::Parser<'a>::parse_fn_decl::h44625901138eaf553CM
  11:        0x111a83cd2 - parse::parser::Parser<'a>::parse_item_fn::h76bb729755ce656afVM
  12:        0x111a79e9a - parse::parser::Parser<'a>::parse_item_::hc402e07115996d8fzUN
  13:        0x111a8a751 - parse::parser::Parser<'a>::parse_mod_items::h12f6ab79c6414614PjN
  14:        0x111a963b3 - parse::parser::Parser<'a>::parse_crate_mod::h66d7caf303a06621FlO
  15:        0x111aaae53 - parse::parse_crate_from_file::hd404c1ea18c1aca1vNV
  16:        0x10e745f66 - driver::phase_1_parse_input::closure.16950
  17:        0x10e71ff13 - driver::phase_1_parse_input::hc6f9fc404efb7c29Qra
  18:        0x10e71cb79 - driver::compile_input::h349b039ebe75c13eGba
  19:        0x10e7f6857 - run_compiler::h1e4d87c6044fbf6dZbc
  20:        0x10e7f3cd1 - thunk::F.Invoke<A, R>::invoke::h2059937391804860278
  21:        0x10e7f2930 - rt::unwind::try::try_fn::h11862807381821880905
  22:        0x1124ca7e9 - rust_try_inner
  23:        0x1124ca7d6 - rust_try
  24:        0x10e7f3095 - thunk::F.Invoke<A, R>::invoke::h6573516661401600357
  25:        0x112439ac3 - sys::thread::thread_start::h9e3555425c6999b2e4G
  26:     0x7fff962fe268 - _pthread_body
  27:     0x7fff962fe1e5 - _pthread_body

[Kimundi]

Hm, seems like another fallout of #22426, but that got fixed already. Is your compiler up-to-date?

[nwin]

No. Downloaded it, but forgot to install.