fixes #7215

compiler/ast.nim

@@ -1661,7 +1661,7 @@ proc isException*(t: PType): bool =
   # check if `y` is object type and it inherits from Exception
   assert(t != nil)
 
-  if t.kind != tyObject: 
+  if t.kind != tyObject:
     return false
 
   var base = t

compiler/vm.nim

@@ -1467,7 +1467,7 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
           "request to create a NimNode of invalid kind")
       let cc = regs[rc].node
 
-      regs[ra].node = newNodeI(TNodeKind(int(k)),
+      let x = newNodeI(TNodeKind(int(k)),
         if cc.kind != nkNilLit:
           cc.info
         elif c.comesFromHeuristic.line > -1:
@@ -1476,7 +1476,10 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
           c.callsite[1].info
         else:
           c.debug[pc])
-      regs[ra].node.flags.incl nfIsRef
+      x.flags.incl nfIsRef
+      # prevent crashes in the compiler resulting from wrong macros:
+      if x.kind == nkIdent: x.ident = getIdent""
+      regs[ra].node = x
     of opcNCopyNimNode:
       decodeB(rkNode)
       regs[ra].node = copyNode(regs[rb].node)

lib/pure/collections/sequtils.nim

@@ -711,7 +711,7 @@ proc mapLitsImpl(constructor: NimNode; op: NimNode; nested: bool;
     result.add op
     result.add constructor
   else:
-    result = newNimNode(constructor.kind, lineInfoFrom=constructor)
+    result = copyNimNode(constructor)
     for v in constructor:
       if nested or v.kind in filter:
         result.add mapLitsImpl(v, op, nested, filter)