revert to old behaviour: tuple field names are not ignored anymore; fixes #1920

compiler/semexprs.nim

@@ -439,12 +439,24 @@ proc changeType(n: PNode, newType: PType, check: bool) =
     let tup = newType.skipTypes({tyGenericInst})
     if tup.kind != tyTuple:
       internalError(n.info, "changeType: no tuple type for constructor")
+    elif newType.n == nil: discard
+    elif sonsLen(n) > 0 and n.sons[0].kind == nkExprColonExpr: 
+      for i in countup(0, sonsLen(n) - 1): 
+        var m = n.sons[i].sons[0]
+        if m.kind != nkSym: 
+          internalError(m.info, "changeType(): invalid tuple constr")
+          return
+        var f = getSymFromList(newType.n, m.sym.name)
+        if f == nil: 
+          internalError(m.info, "changeType(): invalid identifier")
+          return
+        changeType(n.sons[i].sons[1], f.typ, check)
     else:
       for i in countup(0, sonsLen(n) - 1):
         var m = n.sons[i]
-        if m.kind == nkExprColonExpr:
-          m = m.sons[1]
-          n.sons[i] = m
+        var a = newNodeIT(nkExprColonExpr, m.info, newType.sons[i])
+        addSon(a, newSymNode(newType.n.sons[i].sym))
+        addSon(a, m)
         changeType(m, tup.sons[i], check)
   of nkCharLit..nkUInt64Lit:
     if check:

compiler/sigmatch.nim

@@ -357,7 +357,7 @@ proc recordRel(c: var TCandidate, f, a: PType): TTypeRelation =
           var y = a.n.sons[i].sym
           if f.kind == tyObject and typeRel(c, x.typ, y.typ) < isSubtype:
             return isNone
-          if x.name.id != y.name.id and f.kind != tyTuple: return isNone
+          if x.name.id != y.name.id: return isNone
 
 proc allowsNil(f: PType): TTypeRelation {.inline.} =
   result = if tfNotNil notin f.flags: isSubtype else: isNone

compiler/types.nim

@@ -781,6 +781,15 @@ proc sameTuple(a, b: PType, c: var TSameTypeClosure): bool =
       
       result = sameTypeAux(x, y, c)
       if not result: return 
+    if a.n != nil and b.n != nil and IgnoreTupleFields notin c.flags:
+      for i in countup(0, sonsLen(a.n) - 1): 
+        # check field names: 
+        if a.n.sons[i].kind == nkSym and b.n.sons[i].kind == nkSym:
+          var x = a.n.sons[i].sym
+          var y = b.n.sons[i].sym
+          result = x.name.id == y.name.id
+          if not result: break 
+        else: internalError(a.n.info, "sameTuple")
 
 template ifFastObjectTypeCheckFailed(a, b: PType, body: stmt) {.immediate.} =
   if tfFromGeneric notin a.flags + b.flags: