ensure Type{T} gets inserted with the right key when T is a TypeVar (#58577)

Fix #58479

Author: vtjnash

src/typemap.c

@@ -31,7 +31,7 @@ static jl_value_t *jl_type_extract_name(jl_value_t *t1 JL_PROPAGATES_ROOT, int i
         return jl_type_extract_name(jl_unwrap_vararg(t1), invariant);
     }
     else if (jl_is_typevar(t1)) {
-        return jl_type_extract_name(((jl_tvar_t*)t1)->ub, invariant);
+        return jl_type_extract_name(((jl_tvar_t*)t1)->ub, 0);
     }
     else if (t1 == jl_bottom_type || t1 == (jl_value_t*)jl_typeofbottom_type || t1 == (jl_value_t*)jl_typeofbottom_type->super) {
         return (jl_value_t*)jl_typeofbottom_type->name; // put Union{} and typeof(Union{}) and Type{Union{}} together for convenience

test/reflection.jl

@@ -577,6 +577,32 @@ fLargeTable(::Union, ::Union) = "b"
 @test length(methods(fLargeTable)) == 205
 @test fLargeTable(Union{Int, Missing}, Union{Int, Missing}) == "b"
 
+# issue #58479
+fLargeTable(::Type) = "Type"
+fLargeTable(::Type{<:DataType}) = "DataType"
+@test fLargeTable(Type) == "Type"
+@test fLargeTable(DataType) == "DataType"
+@test fLargeTable(Type{DataType}) == "DataType"
+@test fLargeTable(Type{UnionAll}) == "DataType"
+@test fLargeTable(Type{Int}) == "DataType"
+@test fLargeTable(Type{Vector}) == "Type"
+@test fLargeTable(Type{Type{Union{}}}) == "DataType"
+@test fLargeTable(Type{Union{}}) == "Type"
+@test fLargeTable(Union{}) == "DataType"
+@test fLargeTable(Type{<:DataType}) == "Type"
+fLargeTable(::Type{<:UnionAll}) = "UnionAll"
+@test fLargeTable(UnionAll) == "UnionAll"
+@test fLargeTable(Type{Vector}) == "UnionAll"
+@test fLargeTable(Type{Int}) == "DataType"
+@test fLargeTable(Type{Type{Union{}}}) == "DataType"
+@test fLargeTable(Type{Union{}}) == "Type"
+@test_throws MethodError fLargeTable(Union{})
+@test fLargeTable(Type{<:DataType}) == "Type"
+@test fLargeTable(Type{Vector{T}} where T) == "DataType"
+@test fLargeTable(Union{DataType,Type{Vector{T}} where T}) == "DataType"
+@test fLargeTable(Union{DataType,UnionAll,Type{Vector{T}} where T}) == "Type"
+@test fLargeTable(Union{Type{Vector},Type{Vector{T}} where T}) == "Type"
+
 # issue #15280
 function f15280(x) end
 @test functionloc(f15280)[2] > 0