[Bug c/97702] New: comma operator does not drop qualifiers during lvalue conversion

[uecker at eecs dot berkeley.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97702

            Bug ID: 97702
           Summary: comma operator does not drop qualifiers during lvalue
                    conversion
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: uecker at eecs dot berkeley.edu
  Target Milestone: ---

The following code 

const int x = 0;
typeof(0, x) y = 0;
y = x;

yields an error because '(0, x)' and then 'y' is const 
qualified. This is incorrect as lvalue conversion
should remove the qualifier (ISO C17 6.3.2.1p2).

I assume this is a residual problem from the time
where GCC had generalized lvalues.