[all-commits] [llvm/llvm-project] 6bbfa0: When performing template argument deduction to sel...

[Richard Smith via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6bbfa0fd408e81055c360c2e059554dd76fd7f09
      https://github.com/llvm/llvm-project/commit/6bbfa0fd408e81055c360c2e059554dd76fd7f09
  Author: Richard Smith <richard at metafoo.co.uk>
  Date:   2021-05-05 (Wed, 05 May 2021)

  Changed paths:
    M clang/lib/Sema/SemaTemplateDeduction.cpp
    M clang/test/SemaTemplate/partial-spec-instantiate.cpp

  Log Message:
  -----------
  When performing template argument deduction to select a partial
specialization while substituting a partial template parameter pack,
don't try to extend the existing deduction.

This caused us to select the wrong partial specialization in some rare
cases. A recent change to libc++ caused this to happen in practice for
code using std::conjunction.