We were using the type from the wrong Node (the partially filled-in
FUNCINST) rather than the original function node - which is pointed to
by the OFUNCINST)) to set the final fully-substituted type of the
OFUNCINST. So fixed the node reference. Also, added check so we don't do
any work at all if the OFUNCINST already has all type args filled in.
Added few extra cases to the test file issue48030.go, to cover
fully-specified type args, partially inferred type args, and fully
inferred type args.
Fixes#48030
Change-Id: If9e4f2e0514d68b9d241f30c423259133932b25b
Reviewed-on: https://go-review.googlesource.com/c/go/+/346229
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
