From 4ddc5163823b4fb75ab7050bf351310c8e3929ea Mon Sep 17 00:00:00 2001
From: John Sully <john@csquare.ca>
Date: Thu, 4 Jun 2020 00:22:59 -0400
Subject: [PATCH] Extra debug checks in dictmerge

Former-commit-id: 839b2a151e6bad67017de87d7a637359f6ae63d1
---
 src/dict.cpp | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/dict.cpp b/src/dict.cpp
index 7434804af..c99e7dd5b 100644
--- a/src/dict.cpp
+++ b/src/dict.cpp
@@ -190,6 +190,7 @@ int dictMerge(dict *dst, dict *src)
         return DICT_OK;
     }
 
+    size_t expectedSize = dictSize(src) + dictSize(dst);
     if (dictSize(src) > dictSize(dst))
     {
         std::swap(*dst, *src);
@@ -198,10 +199,18 @@ int dictMerge(dict *dst, dict *src)
 
     if (!dictIsRehashing(dst) && !dictIsRehashing(src))
     {
-        dst->ht[1] = dst->ht[0];
-        dst->ht[0] = src->ht[0];
+        if (dst->ht[0].size >= src->ht[0].size)
+        {
+            dst->ht[1] = dst->ht[0];
+            dst->ht[0] = src->ht[0];
+        }
+        else
+        {
+            dst->ht[1] = src->ht[0];
+        }
         _dictReset(&src->ht[0]);
         dst->rehashidx = 0;
+        assert((dictSize(src)+dictSize(dst)) == expectedSize);
         return DICT_OK;
     }
 
@@ -229,6 +238,7 @@ int dictMerge(dict *dst, dict *src)
             }
         }
     }
+    assert((dictSize(src)+dictSize(dst)) == expectedSize);
     return DICT_OK;
 }