Fix guard equality with short-circuit operators

Signed-off-by: José Valim <jose.valim@gmail.com>

Closes #15253.
Closes #15257.

Author: gldubc

lib/elixir/lib/module/types/pattern.ex

@@ -1282,8 +1282,8 @@ defmodule Module.Types.Pattern do
     # only be true if both clauses are executed, so we know the first
     # argument has to be true and the second has to be expected.
     cond do
-      subtype?(expected, both_domain) ->
-        of_logical_all([left | right], true, both_domain, abort_domain, stack, context)
+      is_nil(context.pattern_info) or subtype?(expected, both_domain) ->
+        of_logical_all([left | right], true, expected, abort_domain, stack, context)
 
       right == [] ->
         of_guard(left, expected, left, stack, context)

lib/elixir/test/elixir/module/types/pattern_test.exs

@@ -896,6 +896,24 @@ defmodule Module.Types.PatternTest do
                """
     end
 
+    test "nested conditional checks" do
+      assert typecheck!([a, b], true == (b and a), a) == dynamic(atom([true]))
+      assert typecheck!([a, b], false == (b and a), a) == dynamic(term())
+
+      assert typecheck!([a, b, c], a != (b or c), a) == dynamic(term())
+      assert typecheck!([a, b, c], a == (b or c), a) == dynamic(term())
+      assert typecheck!([a, b, c], a !== (b or c), a) == dynamic(term())
+      assert typecheck!([a, b, c], a === (b or c), a) == dynamic(term())
+      assert typecheck!([a, b, c], a == hd(b or c), a) == dynamic(term())
+      assert typecheck!([a, b, c], a != (b and c), a) == dynamic(term())
+      assert typecheck!([a, b, c], a == (b and c), a) == dynamic(term())
+
+      assert typecheck!([a, b, c], a == :erlang.and(b, c), a) == dynamic(boolean())
+      assert typecheck!([a, b, c], a == :erlang.or(b, c), a) == dynamic(boolean())
+      assert typecheck!([a, b, c], c and a === (b or c), a) == dynamic(atom([true]))
+      assert typecheck!([a, b, c], c and a === (b and c), a) == dynamic(boolean())
+    end
+
     test "domain checks" do
       # Regular domain check
       assert typecheck!([x, z], length(x) == z, x) == dynamic(list(term()))