fixes #16325 [backport:1.4] (#18784)

compiler/sigmatch.nim

@@ -595,8 +595,7 @@ proc procParamTypeRel(c: var TCandidate, f, a: PType): TTypeRelation =
     # if f is metatype.
     result = typeRel(c, f, a)
 
-  #               v--- is this correct?
-  if result <= isIntConv or inconsistentVarTypes(f, a):
+  if result <= isSubrange or inconsistentVarTypes(f, a):
     result = isNone
 
   #if result == isEqual:

tests/overload/tproc_types_dont_like_subtypes.nim

@@ -0,0 +1,20 @@
+discard """
+  errormsg: "got <B, proc (b: B){.closure, gcsafe, locks: 0.}>"
+  line: 20
+"""
+
+type
+  A = ref object of RootObj
+  B = ref object of A
+
+  P = proc (a: A)
+
+# bug #16325
+
+proc doThings(a: A, p: P) =
+  p(a)
+
+var x = proc (b: B) {.closure.} =
+  echo "B"
+
+doThings(B(), x)