Code completion does not work for member of alias template with dependent argument

[HighCommander4]

In the following testcase:

template <typename T>
struct S {
  int a;
};

template <typename T> using Alias = S<T>;

template <typename T>
void f(Alias<T> s) {
  s.^
}

Code completion at the ^ does not offer the member a but should.

(I noticed this while writing this testcase. The seemingly more complicated member-of-a-member scenario works, but this simpler scenario does not.)

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Nathan Ridge (HighCommander4)

In the following testcase:

template <typename T>
struct S {
  int a;
};

template <typename T> using Alias = S<T>;

template <typename T>
void f(Alias<T> s) {
  s.^
}

Code completion at the ^ does not offer the member a but should.

(I noticed this while writing [this testcase](https://searchfox.org/llvm/rev/73e14de207a3aa0fa071fa56756e8e316edf5227/clang/test/CodeCompletion/member-access.cpp#421-437). The seemingly more complicated member-of-a-member scenario works, but this simpler scenario does not.)

[HighCommander4]

Proposed fix: #130473

[zyn0217]

Proposed fix: #128392

Did you mean #130473 ?

[HighCommander4]

Proposed fix: #128392

Did you mean #130473 ?

I did, thanks! Edited to fix.