Bug#27430 Crash in subquery code when in PS and table DDL changed after PREPARE

Add test target to the makefile that will cause all
statements to be re-prepared before execution.


Makefile.am:
  Add test-reprepare target. In combination with the
  --ps-protocol this will cause that every statement
  in the test suite be re-prepared before execution.
sql/sql_base.cc:
  Re-prepare each statement before execution.

Makefile.am

@@ -66,7 +66,7 @@ tags:
   test-pl test-force-pl test-full-pl test-force-full-pl test-force-pl-mem \
   test-unit test-ps test-nr test-pr test-ns test-binlog-statement \
   test-ext-funcs test-ext-rpl test-ext-partitions test-ext-jp \
-  test-ext-stress test-ext test-embedded \
+  test-ext-stress test-ext test-embedded test-reprepare \
   test-fast test-fast-cursor test-fast-view test-fast-prepare \
   test-full-qa
 
@@ -111,6 +111,11 @@ test-embedded:
 	  echo "no program found for 'embedded' tests - skipped testing" ; \
 	fi
 
+test-reprepare:
+	cd mysql-test ; \
+	    @PERL@ ./mysql-test-run.pl $(force) $(mem) --ps-protocol \
+		--mysqld=--debug=+d,reprepare_each_statement
+
 test:	test-unit test-ns test-pr
 
 test-full:	test test-nr test-ps

sql/sql_base.cc

@@ -3770,16 +3770,17 @@ check_and_update_table_version(THD *thd,
     /* Always maintain the latest version and type */
     tables->set_metadata_id(table_share);
   }
-#if 0
+
 #ifndef DBUG_OFF
   /* Spuriously reprepare each statement. */
-  if (thd->m_metadata_observer && thd->stmt_arena->is_reprepared == FALSE)
+  if (_db_strict_keyword_("reprepare_each_statement") &&
+      thd->m_metadata_observer && thd->stmt_arena->is_reprepared == FALSE)
   {
     thd->m_metadata_observer->report_error(thd);
     return TRUE;
   }
 #endif
-#endif
+
   return FALSE;
 }