fix #15750

lib/pure/collections/tables.nim

@@ -1619,6 +1619,8 @@ proc `==`*[A, B](s, t: OrderedTable[A, B]): bool =
 
   if s.counter != t.counter:
     return false
+  if s.counter == 0 and t.counter == 0:
+    return true
   var ht = t.first
   var hs = s.first
   while ht >= 0 and hs >= 0:

tests/collections/ttables.nim

@@ -456,3 +456,9 @@ block testNonPowerOf2:
   var b = initTable[int, int](9)
   b[1] = 10
   assert b[1] == 10
+
+block emptyOrdered:
+  var t1: OrderedTable[int, string]
+  var t2: OrderedTable[int, string]
+  assert t1 == t2
+