fix #32607, bug in typeintersect of X{<:Tuple1} vs. X{Tuple2}

Author: JeffBezanson

src/subtype.c

@@ -2683,26 +2683,16 @@ static jl_value_t *intersect_invariant(jl_value_t *x, jl_value_t *y, jl_stenv_t
         flip_vars(e);
         return jl_bottom_type;
     }
-    /*
-      TODO: This is a band-aid for issue #23685. A better solution would be to
-      first normalize types so that all `where` expressions in covariant position
-      are pulled out to the top level.
-    */
-    if ((jl_is_typevar(x) && !jl_is_typevar(y) && lookup(e, (jl_tvar_t*)x) == NULL) ||
-        (jl_is_typevar(y) && !jl_is_typevar(x) && lookup(e, (jl_tvar_t*)y) == NULL))
-        return ii;
     jl_value_t *root=NULL;
     jl_savedenv_t se;
     JL_GC_PUSH2(&ii, &root);
     save_env(e, &root, &se);
-    if (!subtype_in_env(x, y, e)) {
+    if (!subtype_in_env_existential(x, y, e, 0, e->invdepth)) {
         ii = NULL;
     }
     else {
-        flip_vars(e);
-        if (!subtype_in_env(y, x, e))
+        if (!subtype_in_env_existential(y, x, e, 0, e->invdepth))
             ii = NULL;
-        flip_vars(e);
     }
     restore_env(e, root, &se);
     free(se.buf);

test/subtype.jl

@@ -991,6 +991,17 @@ function test_intersection()
     @test_broken typeintersect(Tuple{Type{Z},Z} where Z,
                                Tuple{Type{Ref{T}} where T, Ref{Float64}}) ==
         Tuple{Type{Ref{Float64}},Ref{Float64}}
+
+    # issue #32607
+    @testintersect(Type{<:Tuple{Integer,Integer}},
+                   Type{Tuple{Int,T}} where T,
+                   Type{Tuple{Int,T}} where T<:Integer)
+    @testintersect(Type{<:Tuple{Any,Vararg{Any}}},
+                   Type{Tuple{Vararg{Int,N}}} where N,
+                   Type{Tuple{Int,Vararg{Int,N}}} where N)
+    @testintersect(Type{<:Array},
+                   Type{AbstractArray{T}} where T,
+                   Bottom)
 end
 
 function test_intersection_properties()