Merge 10.5 into 10.6

Author: dr-m

appveyor.yml

@@ -14,7 +14,7 @@ configuration: RelWithDebInfo
 platform: x64
 
 test_script:
-  - set PATH=%PATH%;C:\Program Files (x86)\Windows Kits\10\Debuggers\x64
+  - set PATH=C:\Strawberry\perl\bin;%PATH%;C:\Program Files (x86)\Windows Kits\10\Debuggers\x64
   - cd %APPVEYOR_BUILD_FOLDER%\win_build\mysql-test
   - perl mysql-test-run.pl --force --max-test-fail=10 --parallel=4 --testcase-timeout=10 --skip-test-list=unstable-tests --suite=main
 

client/completion_hash.cc

@@ -205,7 +205,8 @@ Bucket *find_longest_match(HashTable *ht, char *str, uint length,
 void completion_hash_clean(HashTable *ht)
 {
   free_root(&ht->mem_root,MYF(0));
-  bzero((char*) ht->arBuckets,ht->nTableSize*sizeof(Bucket *));
+  if (size_t s= ht->nTableSize)
+    bzero((char*) ht->arBuckets, s * sizeof(Bucket *));
 }