diff --git a/mysql-test/r/func_json.result b/mysql-test/r/func_json.result
index 6a77648efa5..eff8f5c9c92 100644
--- a/mysql-test/r/func_json.result
+++ b/mysql-test/r/func_json.result
@@ -618,3 +618,14 @@ connection default;
 set @@global.max_allowed_packet = default;
 set @@global.net_buffer_length = default;
 disconnect newconn;
+create table t1(j longtext, p longtext);
+insert into t1 values
+('{"a":1,"b":2,"c":3}','$.a'),
+('{"a":1,"b":2,"c":3}','$.b'),
+('{"a":1,"b":2,"c":3}','$.c');
+select j, p, json_remove(j, p) from t1;
+j	p	json_remove(j, p)
+{"a":1,"b":2,"c":3}	$.a	{"b": 2, "c": 3}
+{"a":1,"b":2,"c":3}	$.b	{"a": 1, "c": 3}
+{"a":1,"b":2,"c":3}	$.c	{"a": 1, "b": 2}
+drop table t1;
diff --git a/mysql-test/suite/innodb/r/trigger_error.result b/mysql-test/suite/innodb/r/trigger_error.result
new file mode 100644
index 00000000000..ef5f910e1a2
--- /dev/null
+++ b/mysql-test/suite/innodb/r/trigger_error.result
@@ -0,0 +1,28 @@
+CREATE TABLE t1 (i INT) ENGINE=InnoDB;
+CREATE TABLE t2 (i INT) ENGINE=InnoDB;
+CREATE OR REPLACE TRIGGER tr1
+AFTER UPDATE ON t2
+FOR EACH ROW
+INSERT INTO tlog (i) VALUES (1);
+INSERT IGNORE INTO t2 VALUES (1);
+CREATE TRIGGER IF NOT EXISTS tr2
+BEFORE INSERT ON t2
+FOR EACH ROW
+INSERT INTO tlog (i) VALUES (2);
+START TRANSACTION;
+INSERT INTO t1 VALUES (1);
+UPDATE t2 SET i = 3;
+ERROR 42S02: Table 'test.tlog' doesn't exist
+INSERT INTO t1 VALUES (2);
+INSERT INTO t2 VALUES (4);
+ERROR 42S02: Table 'test.tlog' doesn't exist
+UPDATE t1 SET i = 4 LIMIT 1;
+COMMIT;
+SELECT * FROM t1;
+i
+4
+2
+SELECT * FROM t2;
+i
+1
+DROP TABLE t1,t2;
diff --git a/mysql-test/suite/innodb/t/trigger_error.test b/mysql-test/suite/innodb/t/trigger_error.test
new file mode 100644
index 00000000000..0334f2b353c
--- /dev/null
+++ b/mysql-test/suite/innodb/t/trigger_error.test
@@ -0,0 +1,31 @@
+--source include/have_innodb.inc
+
+CREATE TABLE t1 (i INT) ENGINE=InnoDB;
+CREATE TABLE t2 (i INT) ENGINE=InnoDB;
+
+CREATE OR REPLACE TRIGGER tr1
+  AFTER UPDATE ON t2
+  FOR EACH ROW
+  INSERT INTO tlog (i) VALUES (1);
+
+INSERT IGNORE INTO t2 VALUES (1);
+
+CREATE TRIGGER IF NOT EXISTS tr2
+  BEFORE INSERT ON t2
+  FOR EACH ROW
+  INSERT INTO tlog (i) VALUES (2);
+
+START TRANSACTION;
+INSERT INTO t1 VALUES (1);
+--error ER_NO_SUCH_TABLE
+UPDATE t2 SET i = 3;
+INSERT INTO t1 VALUES (2);
+--error ER_NO_SUCH_TABLE
+INSERT INTO t2 VALUES (4);
+UPDATE t1 SET i = 4 LIMIT 1;
+COMMIT;
+
+SELECT * FROM t1;
+SELECT * FROM t2;
+
+DROP TABLE t1,t2;
diff --git a/mysql-test/t/func_json.test b/mysql-test/t/func_json.test
index 74692c475f4..72b8681ac44 100644
--- a/mysql-test/t/func_json.test
+++ b/mysql-test/t/func_json.test
@@ -263,3 +263,14 @@ set @@global.max_allowed_packet = default;
 set @@global.net_buffer_length = default;
 --disconnect newconn
 
+
+#
+# MDEV-12262 Assertion `!null_value' failed in virtual bool Item::send on JSON_REMOVE.
+#
+create table t1(j longtext, p longtext);
+insert into t1 values
+    ('{"a":1,"b":2,"c":3}','$.a'),
+    ('{"a":1,"b":2,"c":3}','$.b'),
+      ('{"a":1,"b":2,"c":3}','$.c');
+select j, p, json_remove(j, p) from t1;
+drop table t1;
diff --git a/sql/item_jsonfunc.cc b/sql/item_jsonfunc.cc
index f3090a4097f..b8471dc8244 100644
--- a/sql/item_jsonfunc.cc
+++ b/sql/item_jsonfunc.cc
@@ -2633,6 +2633,7 @@ v_found:
     str->length(0);
 
     if (append_simple(str, js->ptr(), rem_start - js->ptr()) ||
+        (je.state == JST_KEY && n_item > 0 && str->append(",", 1)) ||
         append_simple(str, rem_end, js->end() - rem_end))
           goto js_error; /* Out of memory. */
 
@@ -2658,6 +2659,7 @@ v_found:
   if (json_nice(&je, str, Item_func_json_format::LOOSE))
     goto js_error;
 
+  null_value= 0;
   return str;
 
 js_error:
diff --git a/sql/share/errmsg-utf8.txt b/sql/share/errmsg-utf8.txt
index e984a6d14d8..8f63af78b43 100644
--- a/sql/share/errmsg-utf8.txt
+++ b/sql/share/errmsg-utf8.txt
@@ -7448,6 +7448,8 @@ ER_GEOJSON_NOT_CLOSED
         eng "Incorrect GeoJSON format - polygon not closed."
 ER_JSON_PATH_EMPTY
         eng "Path expression '$' is not allowed in argument %d to function '%s'."
+ER_SLAVE_SAME_ID
+        eng "A slave with the same server_uuid/server_id as this slave has connected to the master"
 ER_ILLEGAL_PARAMETER_DATA_TYPES2_FOR_OPERATION
         eng "Illegal parameter data types %s and %s for operation '%s'"
 ER_ILLEGAL_PARAMETER_DATA_TYPE_FOR_OPERATION
diff --git a/sql/signal_handler.cc b/sql/signal_handler.cc
index dc90fcae576..efcc9a3f0b2 100644
--- a/sql/signal_handler.cc
+++ b/sql/signal_handler.cc
@@ -201,6 +201,9 @@ extern "C" sig_handler handle_fatal_signal(int sig)
     case ABORT_QUERY_HARD:
       kreason= "ABORT_QUERY";
       break;
+    case KILL_SLAVE_SAME_ID:
+      kreason= "KILL_SLAVE_SAME_ID";
+      break;
     }
     my_safe_printf_stderr("%s", "\n"
       "Trying to get some variables.\n"
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 19846da8e8c..fef16acbd20 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -1987,6 +1987,8 @@ int killed_errno(killed_state killed)
   case KILL_SERVER:
   case KILL_SERVER_HARD:
     DBUG_RETURN(ER_SERVER_SHUTDOWN);
+  case KILL_SLAVE_SAME_ID:
+    DBUG_RETURN(ER_SLAVE_SAME_ID);
   }
   DBUG_RETURN(0);                               // Keep compiler happy
 }
diff --git a/sql/sql_class.h b/sql/sql_class.h
index d5afa0a89dd..5b18f99022f 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -477,17 +477,23 @@ enum killed_state
   ABORT_QUERY_HARD= 7,
   KILL_TIMEOUT= 8,
   KILL_TIMEOUT_HARD= 9,
+  /*
+    When binlog reading thread connects to the server it kills
+    all the binlog threads with the same ID.
+  */
+  KILL_SLAVE_SAME_ID= 10,
   /*
     All of the following killed states will kill the connection
     KILL_CONNECTION must be the first of these and it must start with
     an even number (becasue of HARD bit)!
   */
-  KILL_CONNECTION= 10,
-  KILL_CONNECTION_HARD= 11,
-  KILL_SYSTEM_THREAD= 12,
-  KILL_SYSTEM_THREAD_HARD= 13,
-  KILL_SERVER= 14,
-  KILL_SERVER_HARD= 15
+  KILL_CONNECTION= 12,
+  KILL_CONNECTION_HARD= 13,
+  KILL_SYSTEM_THREAD= 14,
+  KILL_SYSTEM_THREAD_HARD= 15,
+  KILL_SERVER= 16,
+  KILL_SERVER_HARD= 17,
+
 };
 
 extern int killed_errno(killed_state killed);
diff --git a/sql/sql_repl.cc b/sql/sql_repl.cc
index 2a22810b8c2..0180671977c 100644
--- a/sql/sql_repl.cc
+++ b/sql/sql_repl.cc
@@ -2910,6 +2910,13 @@ err:
   THD_STAGE_INFO(thd, stage_waiting_to_finalize_termination);
   RUN_HOOK(binlog_transmit, transmit_stop, (thd, flags));
 
+  if (info->thd->killed == KILL_SLAVE_SAME_ID)
+  {
+    info->errmsg= "A slave with the same server_uuid/server_id as this slave "
+                  "has connected to the master";
+    info->error= ER_SLAVE_SAME_ID;
+  }
+
   const bool binlog_open = my_b_inited(&log);
   if (file >= 0)
   {
@@ -2921,7 +2928,8 @@ err:
   thd->variables.max_allowed_packet= old_max_allowed_packet;
   delete info->fdev;
 
-  if (info->error == ER_MASTER_FATAL_ERROR_READING_BINLOG && binlog_open)
+  if ((info->error == ER_MASTER_FATAL_ERROR_READING_BINLOG ||
+       info->error == ER_SLAVE_SAME_ID) && binlog_open)
   {
     /*
        detailing the fatal error message with coordinates
@@ -3392,7 +3400,7 @@ void kill_zombie_dump_threads(uint32 slave_server_id)
       it will be slow because it will iterate through the list
       again. We just to do kill the thread ourselves.
     */
-    tmp->awake(KILL_QUERY);
+    tmp->awake(KILL_SLAVE_SAME_ID);
     mysql_mutex_unlock(&tmp->LOCK_thd_data);
   }
 }
diff --git a/storage/innobase/include/ut0dbg.h b/storage/innobase/include/ut0dbg.h
index 5a373c57c0c..706579a3b9f 100644
--- a/storage/innobase/include/ut0dbg.h
+++ b/storage/innobase/include/ut0dbg.h
@@ -61,7 +61,7 @@ ut_dbg_assertion_failed(
 	ut_dbg_assertion_failed(0, __FILE__, __LINE__)
 
 /** Debug assertion */
-#define ut_ad(EXPR)	DBUG_ASSERT(EXPR)
+#define ut_ad	DBUG_ASSERT
 #ifdef UNIV_DEBUG
 /** Debug statement. Does nothing unless UNIV_DEBUG is defined. */
 #define ut_d(EXPR)	EXPR
diff --git a/storage/innobase/trx/trx0rec.cc b/storage/innobase/trx/trx0rec.cc
index 7c757a027d4..481e14d44de 100644
--- a/storage/innobase/trx/trx0rec.cc
+++ b/storage/innobase/trx/trx0rec.cc
@@ -2005,10 +2005,9 @@ trx_undo_report_row_operation(
 			undo->empty = FALSE;
 			undo->top_page_no = page_no;
 			undo->top_offset  = offset;
-			undo->top_undo_no = trx->undo_no;
+			undo->top_undo_no = trx->undo_no++;
 			undo->guess_block = undo_block;
 
-			trx->undo_no++;
 			trx->undo_rseg_space = rseg->space;
 
 			mutex_exit(&trx->undo_mutex);
diff --git a/storage/innobase/trx/trx0roll.cc b/storage/innobase/trx/trx0roll.cc
index cc41d318188..1a997330a9e 100644
--- a/storage/innobase/trx/trx0roll.cc
+++ b/storage/innobase/trx/trx0roll.cc
@@ -990,11 +990,11 @@ trx_roll_pop_top_rec_of_trx(trx_t* trx, roll_ptr_t* roll_ptr, mem_heap_t* heap)
 	trx_undo_t*	temp	= trx->rsegs.m_noredo.undo;
 	const undo_no_t	limit	= trx->roll_limit;
 
-	ut_ad(!insert || !update || !insert->top_undo_no
+	ut_ad(!insert || !update || insert->empty || update->empty
 	      || insert->top_undo_no != update->top_undo_no);
-	ut_ad(!insert || !temp || !insert->top_undo_no
+	ut_ad(!insert || !temp || insert->empty || temp->empty
 	      || insert->top_undo_no != temp->top_undo_no);
-	ut_ad(!update || !temp || !update->top_undo_no
+	ut_ad(!update || !temp || update->empty || temp->empty
 	      || update->top_undo_no != temp->top_undo_no);
 
 	if (insert && !insert->empty && limit <= insert->top_undo_no) {