Merge 10.2 into 10.3

2 files changed, 35 insertions, 29 deletions

diff --git a/sql/sql_admin.cc b/sql/sql_admin.cc
index 92e88a74217..692ae7b00fa 100644
--- a/sql/sql_admin.cc
+++ b/sql/sql_admin.cc
@@ -772,31 +772,6 @@ static bool mysql_admin_table(THD* thd, TABLE_LIST* tables,
         (table->table->s->table_category == TABLE_CATEGORY_USER &&
          (get_use_stat_tables_mode(thd) > NEVER ||
           lex->with_persistent_for_clause));
-
-
-      if (!lex->index_list)
-      {
-        tab->keys_in_use_for_query.init(tab->s->keys);
-      }
-      else
-      {
-        int pos;
-        LEX_STRING *index_name;
-        List_iterator_fast<LEX_STRING> it(*lex->index_list);
-   
-        tab->keys_in_use_for_query.clear_all();  
-        while ((index_name= it++))
-	{
-          if (tab->s->keynames.type_names == 0 ||
-              (pos= find_type(&tab->s->keynames, index_name->str,
-                              index_name->length, 1)) <= 0)
-          {
-            compl_result_code= result_code= HA_ADMIN_INVALID;
-            break;
-          }
-          tab->keys_in_use_for_query.set_bit(--pos);
-        }  
-      }
     }
 
     if (result_code == HA_ADMIN_OK)
@@ -881,6 +856,27 @@ static bool mysql_admin_table(THD* thd, TABLE_LIST* tables,
           }
           tab->file->column_bitmaps_signal();
         }
+        if (!lex->index_list)
+          tab->keys_in_use_for_query.init(tab->s->keys);
+        else
+        {
+          int pos;
+          LEX_STRING *index_name;
+          List_iterator_fast<LEX_STRING> it(*lex->index_list);
+
+          tab->keys_in_use_for_query.clear_all();
+          while ((index_name= it++))
+          {
+            if (tab->s->keynames.type_names == 0 ||
+                (pos= find_type(&tab->s->keynames, index_name->str,
+                                index_name->length, 1)) <= 0)
+            {
+              compl_result_code= result_code= HA_ADMIN_INVALID;
+              break;
+            }
+            tab->keys_in_use_for_query.set_bit(--pos);
+          }
+        }
         if (!(compl_result_code=
               alloc_statistics_for_table(thd, table->table)) &&
             !(compl_result_code=
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 9c206a7fa18..f958e17a9f2 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -4786,6 +4786,7 @@ extern "C" LEX_STRING * thd_query_string (MYSQL_THD thd)
   @param buflen  Length of the buffer
 
   @return Length of the query
+  @retval 0 if LOCK_thd_data cannot be acquired without waiting
 
   @note This function is thread safe as the query string is
         accessed under mutex protection and the string is copied
@@ -4794,10 +4795,19 @@ extern "C" LEX_STRING * thd_query_string (MYSQL_THD thd)
 
 extern "C" size_t thd_query_safe(MYSQL_THD thd, char *buf, size_t buflen)
 {
-  mysql_mutex_lock(&thd->LOCK_thd_data);
-  size_t len= MY_MIN(buflen - 1, thd->query_length());
-  memcpy(buf, thd->query(), len);
-  mysql_mutex_unlock(&thd->LOCK_thd_data);
+  size_t len= 0;
+  /* InnoDB invokes this function while holding internal mutexes.
+  THD::awake() will hold LOCK_thd_data while invoking an InnoDB
+  function that would acquire the internal mutex. Because this
+  function is a non-essential part of information_schema view output,
+  we will break the deadlock by avoiding a mutex wait here
+  and returning the empty string if a wait would be needed. */
+  if (!mysql_mutex_trylock(&thd->LOCK_thd_data))
+  {
+    len= MY_MIN(buflen - 1, thd->query_length());
+    memcpy(buf, thd->query(), len);
+    mysql_mutex_unlock(&thd->LOCK_thd_data);
+  }
   buf[len]= '\0';
   return len;
 }