From 4077050a423973c9d713f67ebf73c94e83392e17 Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Mon, 5 Sep 2016 08:51:38 +0200
Subject: [PATCH] fixes a critical tables bug that caused 'enlarge' to crash
 after 'add'

---
 lib/pure/collections/sharedtables.nim | 19 +++++++++++--------
 lib/pure/collections/tables.nim       |  9 ++++++---
 tests/collections/tableadds.nim       | 13 +++++++++++++
 3 files changed, 30 insertions(+), 11 deletions(-)
 create mode 100644 tests/collections/tableadds.nim

diff --git a/lib/pure/collections/sharedtables.nim b/lib/pure/collections/sharedtables.nim
index 17600b272..7dc338f4e 100644
--- a/lib/pure/collections/sharedtables.nim
+++ b/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):
-      var j = -1 - rawGetKnownHC(t, n[i].key, n[i].hcode)
-      rawInsert(t, t.data, n[i].key, n[i].val, n[i].hcode, j)
+    let eh = n[i].hcode
+    if isFilled(eh):
+      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) =
@@ -47,7 +50,7 @@ template withLock(t, x: untyped) =
 
 template withValue*[A, B](t: var SharedTable[A, B], key: A,
                           value, body: untyped) =
-  ## retrieves the value at ``t[key]``. 
+  ## retrieves the value at ``t[key]``.
   ## `value` can be modified in the scope of the ``withValue`` call.
   ##
   ## .. code-block:: nim
@@ -55,7 +58,7 @@ template withValue*[A, B](t: var SharedTable[A, B], key: A,
   ##   sharedTable.withValue(key, value) do:
   ##     # block is executed only if ``key`` in ``t``
   ##     # value is threadsafe in block
-  ##     value.name = "username" 
+  ##     value.name = "username"
   ##     value.uid = 1000
   ##
   acquire(t.lock)
@@ -71,15 +74,15 @@ template withValue*[A, B](t: var SharedTable[A, B], key: A,
 
 template withValue*[A, B](t: var SharedTable[A, B], key: A,
                           value, body1, body2: untyped) =
-  ## retrieves the value at ``t[key]``. 
+  ## retrieves the value at ``t[key]``.
   ## `value` can be modified in the scope of the ``withValue`` call.
-  ## 
+  ##
   ## .. code-block:: nim
   ##
   ##   sharedTable.withValue(key, value) do:
   ##     # block is executed only if ``key`` in ``t``
   ##     # value is threadsafe in block
-  ##     value.name = "username" 
+  ##     value.name = "username"
   ##     value.uid = 1000
   ##   do:
   ##     # block is executed when ``key`` not in ``t``
diff --git a/lib/pure/collections/tables.nim b/lib/pure/collections/tables.nim
index 3f06762ae..9fa8f5263 100644
--- a/lib/pure/collections/tables.nim
+++ b/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):
-      var j = -1 - rawGetKnownHC(t, n[i].key, n[i].hcode)
-      rawInsert(t, t.data, n[i].key, n[i].val, n[i].hcode, j)
+    let eh = n[i].hcode
+    if isFilled(eh):
+      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
diff --git a/tests/collections/tableadds.nim b/tests/collections/tableadds.nim
new file mode 100644
index 000000000..71f1fad7d
--- /dev/null
+++ b/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"