From e95f78f4752e4c0433e969f34e01b4b6be39efa1 Mon Sep 17 00:00:00 2001
From: Andrei Elkin <andrei.elkin@mariadb.com>
Date: Wed, 16 Jun 2021 17:10:11 +0300
Subject: [PATCH] MDEV-21117 post-push to cover a "custom" xid format

Due to wsrep uses its own xid format for its recovery,
the xid hashing has to be refined.
When a xid object is not in the server "mysql" format,
the hash record made to contain the xid also in the full format.
---
 sql/handler.cc | 41 ++++++++++++++++++++++++++++-------------
 sql/handler.h  |  6 ++++--
 2 files changed, 32 insertions(+), 15 deletions(-)

diff --git a/sql/handler.cc b/sql/handler.cc
index 0ec8afde16e..393f6234653 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -2399,15 +2399,22 @@ struct xarecover_st
            or NULL.
 */
 static xid_recovery_member*
-xid_member_insert(HASH *hash_arg, my_xid xid_arg, MEM_ROOT *ptr_mem_root)
+xid_member_insert(HASH *hash_arg, my_xid xid_arg, MEM_ROOT *ptr_mem_root,
+                  XID *full_xid_arg)
 {
   xid_recovery_member *member= (xid_recovery_member *)
     alloc_root(ptr_mem_root, sizeof(xid_recovery_member));
+  XID *xid_full= NULL;
 
-  if (!member)
+  if (full_xid_arg)
+    xid_full= (XID*) alloc_root(ptr_mem_root, sizeof(XID));
+
+  if (!member || (full_xid_arg && !xid_full))
     return NULL;
 
-  *member= xid_recovery_member(xid_arg, 1, false);
+  if (full_xid_arg)
+    *xid_full= *full_xid_arg;
+  *member= xid_recovery_member(xid_arg, 1, false, xid_full);
 
   return
     my_hash_insert(hash_arg, (uchar*) member) ? NULL : member;
@@ -2421,14 +2428,15 @@ xid_member_insert(HASH *hash_arg, my_xid xid_arg, MEM_ROOT *ptr_mem_root)
            true   otherwise.
 */
 static bool xid_member_replace(HASH *hash_arg, my_xid xid_arg,
-                               MEM_ROOT *ptr_mem_root)
+                               MEM_ROOT *ptr_mem_root,
+                               XID *full_xid_arg)
 {
   xid_recovery_member* member;
   if ((member= (xid_recovery_member *)
        my_hash_search(hash_arg, (uchar *)& xid_arg, sizeof(xid_arg))))
     member->in_engine_prepare++;
   else
-    member= xid_member_insert(hash_arg, xid_arg, ptr_mem_root);
+    member= xid_member_insert(hash_arg, xid_arg, ptr_mem_root, full_xid_arg);
 
   return member == NULL;
 }
@@ -2479,7 +2487,10 @@ static void xarecover_do_commit_or_rollback(handlerton *hton,
   xid_recovery_member *member= arg->member;
   Binlog_offset *ptr_commit_max= arg->binlog_coord;
 
-  x.set(member->xid);
+  if (!member->full_xid)
+    x.set(member->xid);
+  else
+    x= *member->full_xid;
 
   rc= xarecover_decide_to_commit(member, ptr_commit_max) ?
     hton->commit_by_xid(hton, &x) : hton->rollback_by_xid(hton, &x);
@@ -2601,10 +2612,13 @@ static my_bool xarecover_handlerton(THD *unused, plugin_ref plugin,
 
       for (int i=0; i < got; i ++)
       {
-        my_xid x= IF_WSREP(wsrep_is_wsrep_xid(&info->list[i]) ?
-                           wsrep_xid_seqno(&info->list[i]) :
-                           info->list[i].get_my_xid(),
-                           info->list[i].get_my_xid());
+        my_xid x= info->list[i].get_my_xid();
+        bool is_server_xid= x > 0;
+
+#ifdef WITH_WSREP
+        if (!is_server_xid && wsrep_is_wsrep_xid(&info->list[i]))
+          x= wsrep_xid_seqno(&info->list[i]);
+#endif
         if (!x) // not "mine" - that is generated by external TM
         {
           DBUG_EXECUTE("info",{
@@ -2630,7 +2644,9 @@ static my_bool xarecover_handlerton(THD *unused, plugin_ref plugin,
         */
         if (info->mem_root)
         {
-          if (xid_member_replace(info->commit_list, x, info->mem_root))
+          // remember "full" xid too when it's not in mysql format
+          if (xid_member_replace(info->commit_list, x, info->mem_root,
+                                 is_server_xid? NULL : &info->list[i]))
           {
             info->error= true;
             sql_print_error("Error in memory allocation at xarecover_handlerton");
@@ -2651,8 +2667,7 @@ static my_bool xarecover_handlerton(THD *unused, plugin_ref plugin,
               });
           }
         }
-        else if (WSREP_ON ||
-                 tc_heuristic_recover == TC_HEURISTIC_RECOVER_ROLLBACK)
+        else if (!info->mem_root)
         {
           int rc= hton->rollback_by_xid(hton, info->list+i);
           if (rc == 0)
diff --git a/sql/handler.h b/sql/handler.h
index 2f15ec8f389..7ad00ee546b 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -956,10 +956,12 @@ struct xid_recovery_member
   uint in_engine_prepare;  // number of engines that have xid prepared
   bool decided_to_commit;
   Binlog_offset binlog_coord; // semisync recovery binlog offset
+  XID *full_xid;           // needed by wsrep or past it recovery
 
-  xid_recovery_member(my_xid xid_arg, uint prepare_arg, bool decided_arg)
+  xid_recovery_member(my_xid xid_arg, uint prepare_arg, bool decided_arg,
+                      XID *full_xid_arg)
     : xid(xid_arg), in_engine_prepare(prepare_arg),
-      decided_to_commit(decided_arg) {};
+      decided_to_commit(decided_arg), full_xid(full_xid_arg) {};
 };
 
 /* for recover() handlerton call */