diff --git a/sql/handler.cc b/sql/handler.cc
index 06c407b572a..711fac116f5 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -3851,6 +3851,10 @@ uint handler::get_dup_key(int error)
       error == HA_ERR_FOUND_DUPP_UNIQUE || error == HA_ERR_NULL_IN_SPATIAL ||
       error == HA_ERR_DROP_INDEX_FK)
     table->file->info(HA_STATUS_ERRKEY | HA_STATUS_NO_LOCK);
+  else
+    sql_print_error("get_dup_key: %d", error);
+    /* else part is MDEV-15237 patch */
+
   DBUG_RETURN(table->file->errkey);
 }
 
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index 7ac7495e221..fb2d08f9637 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -14514,7 +14514,17 @@ ha_innobase::info_low(
 		if (err_index) {
 			errkey = innobase_get_mysql_key_number_for_index(
 					m_share, table, ib_table, err_index);
+            /* MDEV-15237 patch begin */
+            sql_print_error("err_index (%d) for %s:%s",
+					errkey, err_index->name,
+					m_prebuilt->table->name.m_name);
+            /* MDEV-15237 patch end */
 		} else {
+            /* MDEV-15237 patch begin */
+			sql_print_error("no err_index (" ULINTPF ") for %s",
+					m_prebuilt->trx->error_key_num,
+					m_prebuilt->table->name.m_name);
+            /* MDEV-15237 patch end */
 			errkey = (unsigned int) (
 				(m_prebuilt->trx->error_key_num
 				 == ULINT_UNDEFINED)