close #21257 (#21275)

* close #21257

* fix generics

compiler/semtypes.nim

@@ -1310,13 +1310,15 @@ proc semProcTypeNode(c: PContext, n, genericParams: PNode,
     if hasDefault:
       def = a[^1]
       block determineType:
+        var defTyp = typ
         if genericParams != nil and genericParams.len > 0:
+          defTyp = nil
           def = semGenericStmt(c, def)
           if hasUnresolvedArgs(c, def):
             def.typ = makeTypeFromExpr(c, def.copyTree)
             break determineType
 
-        def = semExprWithType(c, def, {efDetermineType})
+        def = semExprWithType(c, def, {efDetermineType}, defTyp)
         if def.referencesAnotherParam(getCurrOwner(c)):
           def.flags.incl nfDefaultRefsParam
 

tests/errmsgs/t21257.nim

@@ -0,0 +1,20 @@
+discard """
+  action: compile
+  cmd: "nim check $file" 
+"""
+
+type AC_WINCTRL_Fields* = distinct uint8
+
+type AC_STATUSA_WSTATE0* {.pure.} = enum
+  ABOVE = 0x0,
+  INSIDE = 0x1,
+  BELOW = 0x2,
+
+type AC_WINCTRL_WINTSEL0* {.pure.} = enum
+  ABOVE = 0x0,
+  INSIDE = 0x1,
+  BELOW = 0x2,
+  OUTSIDE = 0x3,
+
+proc write*(WINTSEL0: AC_WINCTRL_WINTSEL0 = ABOVE) =
+  discard