fixes #5519

compiler/transf.nim

@@ -190,9 +190,12 @@ proc transformVarSection(c: PTransf, v: PNode): PTransNode =
       var L = sonsLen(it)
       var defs = newTransNode(it.kind, it.info, L)
       for j in countup(0, L-3):
-        let x = freshVar(c, it.sons[j].sym)
-        idNodeTablePut(c.transCon.mapping, it.sons[j].sym, x)
-        defs[j] = x.PTransNode
+        if it[j].kind == nkSym:
+          let x = freshVar(c, it.sons[j].sym)
+          idNodeTablePut(c.transCon.mapping, it.sons[j].sym, x)
+          defs[j] = x.PTransNode
+        else:
+          defs[j] = transform(c, it[j])
       assert(it.sons[L-2].kind == nkEmpty)
       defs[L-2] = newNodeI(nkEmpty, it.info).PTransNode
       defs[L-1] = transform(c, it.sons[L-1])

tests/iter/tclosureiters.nim

@@ -103,3 +103,39 @@ proc unusedB =
   var count = 0
   for line in lineIter2("temp10.nim"):
     count += 1
+
+# bug #5519
+import os, algorithm
+
+iterator filesIt(path: string): auto {.closure.} =
+  var files = newSeq[string]()
+  var dirs = newSeq[string]()
+  for k, p in os.walkDir(path):
+    let (_, n, e) = p.splitFile
+    if e != "":
+      continue
+    case k
+    of pcFile, pcLinkToFile:
+      files.add(n)
+    else:
+      dirs.add(n)
+  files.sort(system.cmp)
+  dirs.sort(system.cmp)
+  for f in files:
+    yield f
+
+  for d in dirs:
+    files = newSeq[string]()
+    for k, p in os.walkDir(path / d):
+      let (_, n, e) = p.splitFile
+      if e != "":
+        continue
+      case k
+      of pcFile, pcLinkToFile:
+        files.add(n)
+      else:
+        discard
+    files.sort(system.cmp)
+    let prefix = path.splitPath[1]
+    for f in files:
+      yield prefix / f