diff options
Diffstat (limited to 'lib/compiler/src/beam_ssa_type.erl')
-rw-r--r-- | lib/compiler/src/beam_ssa_type.erl | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/lib/compiler/src/beam_ssa_type.erl b/lib/compiler/src/beam_ssa_type.erl index ca5b3d93a9..f1c0030b3c 100644 --- a/lib/compiler/src/beam_ssa_type.erl +++ b/lib/compiler/src/beam_ssa_type.erl @@ -990,11 +990,15 @@ type(call, [#b_remote{mod=#b_literal{val=Mod}, {_,_} -> #t_tuple{} end; - {erlang,'++',[List1,List2]} -> - case get_type(List1, Ts) =:= cons orelse - get_type(List2, Ts) =:= cons of - true -> cons; - false -> list + {erlang,'++',[LHS,RHS]} -> + LType = get_type(LHS, Ts), + RType = get_type(RHS, Ts), + case LType =:= cons orelse RType =:= cons of + true -> + cons; + false -> + %% `[] ++ RHS` yields RHS, even if RHS is not a list. + join(list, RType) end; {erlang,'--',[_,_]} -> list; |