fixes #1053, fixes #924

compiler/ccgexprs.nim

@@ -20,7 +20,7 @@ proc int64Literal(i: BiggestInt): PRope =
 proc uint64Literal(i: uint64): PRope = toRope($i & "ULL")
 
 proc intLiteral(i: BiggestInt): PRope =
-  if (i > low(int32)) and (i <= high(int32)):
+  if i > low(int32) and i <= high(int32):
     result = toRope(i)
   elif i == low(int32):
     # Nim has the same bug for the same reasons :-)
@@ -39,7 +39,7 @@ proc int32Literal(i: int): PRope =
 proc genHexLiteral(v: PNode): PRope =
   # hex literals are unsigned in C
   # so we don't generate hex literals any longer.
-  if not (v.kind in {nkIntLit..nkUInt64Lit}):
+  if v.kind notin {nkIntLit..nkUInt64Lit}:
     internalError(v.info, "genHexLiteral")
   result = intLiteral(v.intVal)
 
@@ -224,9 +224,9 @@ proc optAsgnLoc(a: TLoc, t: PType, field: PRope): TLoc =
 proc genOptAsgnTuple(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
   let newflags =
     if src.k == locData:
-      flags + { needToCopy }
+      flags + {needToCopy}
     elif tfShallow in dest.t.flags:
-      flags - { needToCopy }
+      flags - {needToCopy}
     else:
       flags
   for i in 0 .. <dest.t.len:
@@ -240,9 +240,9 @@ proc genOptAsgnObject(p: BProc, dest, src: TLoc, flags: TAssignmentFlags,
   if t == nil: return
   let newflags =
     if src.k == locData:
-      flags + { needToCopy }
+      flags + {needToCopy}
     elif tfShallow in dest.t.flags:
-      flags - { needToCopy }
+      flags - {needToCopy}
     else:
       flags
   case t.kind
@@ -328,7 +328,9 @@ proc genAssignment(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
       linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
   of tyObject:
     # XXX: check for subtyping?
-    if needsComplexAssignment(ty):
+    if not isObjLackingTypeField(ty):
+      genGenericAsgn(p, dest, src, flags)
+    elif needsComplexAssignment(ty):
       if ty.sons[0].isNil and asgnComplexity(ty.n) <= 4:
         discard getTypeDesc(p.module, ty)
         internalAssert ty.n != nil

lib/system/assign.nim

@@ -70,13 +70,17 @@ proc genericAssignAux(dest, src: pointer, mt: PNimType, shallow: bool) =
                      GenericSeqSize),
         mt.base, shallow)
   of tyObject:
-    # we need to copy m_type field for tyObject, as it could be empty for
-    # sequence reallocations:
-    var pint = cast[ptr PNimType](dest)
-    pint[] = cast[ptr PNimType](src)[]
     if mt.base != nil:
       genericAssignAux(dest, src, mt.base, shallow)
     genericAssignAux(dest, src, mt.node, shallow)
+    # we need to copy m_type field for tyObject, as it could be empty for
+    # sequence reallocations:
+    var pint = cast[ptr PNimType](dest)
+    # We need to copy the *static* type not the dynamic type:
+    #   if p of TB:
+    #     var tbObj = TB(p)
+    #     tbObj of TC # needs to be false!
+    pint[] = mt # cast[ptr PNimType](src)[]
   of tyTuple:
     genericAssignAux(dest, src, mt.node, shallow)
   of tyArray, tyArrayConstr:

tests/objects/tinherentedvalues.nim

@@ -0,0 +1,55 @@
+discard """
+  output: '''tbObj of TC false
+false
+true
+5
+false'''
+"""
+
+# bug #1053
+type
+  TA = object of TObject
+    a: int
+
+  TB = object of TA
+    b: int
+
+  TC = object of TB
+    c: int
+
+proc test(p: TA) =
+  #echo "p of TB ", p of TB
+  if p of TB:
+    var tbObj = TB(p)
+
+    # tbObj is actually no longer compatible with TC:
+    echo "tbObj of TC ", tbObj of TC
+
+var v = TC()
+v.a = 1
+v.b = 2
+v.c = 3
+test(v)
+
+
+# bug #924
+type
+  MyObject = object of TObject
+    x: int
+
+var
+  asd: MyObject
+
+proc isMyObject(obj: TObject) =
+    echo obj of MyObject
+    if obj of MyObject:
+        let a = MyObject(obj)
+        echo a.x
+
+asd.x = 5
+
+var asdCopy = TObject(asd)
+echo asdCopy of MyObject
+
+isMyObject(asd)
+isMyObject(asdCopy)