fixes a critical tables bug that caused 'enlarge' to crash after 'add'

lib/pure/collections/sharedtables.nim

@@ -35,9 +35,12 @@ proc enlarge[A, B](t: var SharedTable[A, B]) =
   t.dataLen = size
   swap(t.data, n)
   for i in 0..<oldSize:
-    if isFilled(n[i].hcode):
+    let eh = n[i].hcode
-      var j = -1 - rawGetKnownHC(t, n[i].key, n[i].hcode)
+    if isFilled(eh):
-      rawInsert(t, t.data, n[i].key, n[i].val, n[i].hcode, j)
+      var j: Hash = eh and maxHash(t)
+      while isFilled(t.data[j].hcode):
+        j = nextTry(j, maxHash(t))
+      rawInsert(t, t.data, n[i].key, n[i].val, eh, j)
   deallocShared(n)
 
 template withLock(t, x: untyped) =

lib/pure/collections/tables.nim

@@ -270,9 +270,12 @@ proc enlarge[A, B](t: var Table[A, B]) =
   newSeq(n, len(t.data) * growthFactor)
   swap(t.data, n)
   for i in countup(0, high(n)):
-    if isFilled(n[i].hcode):
+    let eh = n[i].hcode
-      var j = -1 - rawGetKnownHC(t, n[i].key, n[i].hcode)
+    if isFilled(eh):
-      rawInsert(t, t.data, n[i].key, n[i].val, n[i].hcode, j)
+      var j: Hash = eh and maxHash(t)
+      while isFilled(t.data[j].hcode):
+        j = nextTry(j, maxHash(t))
+      rawInsert(t, t.data, n[i].key, n[i].val, eh, j)
 
 proc mgetOrPut*[A, B](t: var Table[A, B], key: A, val: B): var B =
   ## retrieves value at ``t[key]`` or puts ``val`` if not present, either way

tests/collections/tableadds.nim

@@ -0,0 +1,13 @@
+discard """
+  output: '''done'''
+"""
+
+import tables
+
+proc main =
+  var tab = newTable[string, string]()
+  for i in 0..1000:
+    tab.add "key", "value " & $i
+
+main()
+echo "done"