Merge branch 'mysql/5.5' into 5.5

1 files changed, 35 insertions, 15 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 828dab7ef99..91aecadfd0a 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1,4 +1,4 @@
-/* Copyright (c) 2000, 2015 Oracle and/or its affiliates.
+/* Copyright (c) 2000, 2016 Oracle and/or its affiliates.
    Copyright (c) 2009, 2016 MariaDB
 
    This program is free software; you can redistribute it and/or modify
@@ -23128,32 +23128,52 @@ static void print_join(THD *thd,
   /* List is reversed => we should reverse it before using */
   List_iterator_fast<TABLE_LIST> ti(*tables);
   TABLE_LIST **table;
-  uint non_const_tables= 0;
+
+  /*
+    If the QT_NO_DATA_EXPANSION flag is specified, we print the
+    original table list, including constant tables that have been
+    optimized away, as the constant tables may be referenced in the
+    expression printed by Item_field::print() when this flag is given.
+    Otherwise, only non-const tables are printed.
+
+    Example:
+
+    Original SQL:
+    select * from (select 1) t
+
+    Printed without QT_NO_DATA_EXPANSION:
+    select '1' AS `1` from dual
+
+    Printed with QT_NO_DATA_EXPANSION:
+    select `t`.`1` from (select 1 AS `1`) `t`
+  */
+  const bool print_const_tables= (query_type & QT_NO_DATA_EXPANSION);
+  size_t tables_to_print= 0;
 
   for (TABLE_LIST *t= ti++; t ; t= ti++)
   {
-    /* 
-      See comment in print_table_array() about the second part of the
-      condition 
-    */
-    if (!t->optimized_away && !is_eliminated_table(eliminated_tables, t))
-      non_const_tables++;
+    /* See comment in print_table_array() about the second condition */
+    if (print_const_tables || !t->optimized_away)
+      if (!is_eliminated_table(eliminated_tables, t))
+        tables_to_print++;
   }
-  if (!non_const_tables)
+  if (tables_to_print == 0)
   {
     str->append(STRING_WITH_LEN("dual"));
     return; // all tables were optimized away
   }
   ti.rewind();
 
-  if (!(table= (TABLE_LIST **)thd->alloc(sizeof(TABLE_LIST*) *
-                                                non_const_tables)))
+  if (!(table= static_cast<TABLE_LIST **>(thd->alloc(sizeof(TABLE_LIST*) *
+                                                     tables_to_print))))
     return;  // out of memory
 
-  TABLE_LIST *tmp, **t= table + (non_const_tables - 1);
+  TABLE_LIST *tmp, **t= table + (tables_to_print - 1);
   while ((tmp= ti++))
   {
-    if (tmp->optimized_away || is_eliminated_table(eliminated_tables, tmp))
+    if (tmp->optimized_away && !print_const_tables)
+      continue;
+    if (is_eliminated_table(eliminated_tables, tmp))
       continue;
     *t--= tmp;
   }
@@ -23173,7 +23193,7 @@ static void print_join(THD *thd,
   */
   if ((*table)->sj_inner_tables)
   {
-    TABLE_LIST **end= table + non_const_tables;
+    TABLE_LIST **end= table + tables_to_print;
     for (TABLE_LIST **t2= table; t2!=end; t2++)
     {
       if (!(*t2)->sj_inner_tables)
@@ -23186,7 +23206,7 @@ static void print_join(THD *thd,
     }
   }
   print_table_array(thd, eliminated_tables, str, table, 
-                    table +  non_const_tables, query_type);
+                    table +  tables_to_print, query_type);
 }
 
 /**