fix JuliaLang#38279, yet another bounds circularity in type intersect…

…ion (JuliaLang#38288)
inkydragon · Nov 3, 2020 · 2af16f9 · 2af16f9
1 parent 2890a71
commit 2af16f9
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Showing 2 changed files with 11 additions and 4 deletions.
diff --git a/src/subtype.c b/src/subtype.c
@@ -2964,8 +2964,10 @@ static jl_value_t *intersect(jl_value_t *x, jl_value_t *y, jl_stenv_t *e, int pa
  assert(yy->lb != y);
  }
  if (xx) {
- xx->lb = y;
- xx->ub = y;
+ if (!compareto_var(y, (jl_tvar_t*)x, e, -1))
+ xx->lb = y;
+ if (!compareto_var(y, (jl_tvar_t*)x, e, 1))
+ xx->ub = y;
  assert(xx->ub != x);
  }
  JL_GC_POP();

diff --git a/test/subtype.jl b/test/subtype.jl
@@ -1791,13 +1791,18 @@ let X1 = Tuple{AlmostLU, Vector{T}} where T,
  @test_broken I == actual
 end
 
-# issue #22787
-# for now check that these don't stack overflow
 let
+ # issue #22787
+ # for now check that these don't stack overflow
  t = typeintersect(Tuple{Type{Q}, Q, Ref{Q}} where Q<:Ref,
  Tuple{Type{S}, Union{Ref{S}, Ref{R}}, R} where R where S)
  @test_broken t != Union{}
  t = typeintersect(Tuple{Type{T}, T, Ref{T}} where T,
  Tuple{Type{S}, Ref{S}, S} where S)
  @test_broken t != Union{}
+
+ # issue #38279
+ t = typeintersect(Tuple{<:Array{T, N}, Val{T}} where {T<:Real, N},
+ Tuple{<:Array{T, N}, Val{<:AbstractString}} where {T<:Real, N})
+ @test t == Tuple{<:Array{Union{}, N}, Val{Union{}}} where N
 end