Fixed lp:879939 "assertion in ha_maria::enable_indexes with derived_with_keys=on"

Honor unique/not unique when creating keys for internal tempory tables.
Added new variables to be used to limit how keys are created for internal temporary tables.


include/maria.h:
  Added maria_max_key_length() and maria_max_key_segments()
include/myisam.h:
  Added myisam_max_key_length() and myisam_max_key_segments()
mysql-test/r/mysql.result:
  Drop all used tables
mysql-test/r/subselect4.result:
  Added test case for lp:879939
mysql-test/t/mysql.test:
  Drop all used tables
mysql-test/t/subselect4.test:
  Added test case for lp:879939
sql/mysql_priv.h:
  Added internal_tmp_table_max_key_length and internal_tmp_table_max_key_segments to be used to limit how keys for derived tables are created.
sql/mysqld.cc:
  Added internal_tmp_table_max_key_length and internal_tmp_table_max_key_segments to be used to limit how keys for derived tables are created.
sql/share/errmsg.txt:
  Added new error message for internal errors
sql/sql_select.cc:
  Give error if we try to create a wrong key (this error should never happen)
  Honor unique/not unique when creating keys for internal tempory tables.
storage/maria/ha_maria.cc:
  Added change_table_ptr() to ensure that external_ref points always to the correct table.
  (Not having this caused an assert in the included test)
storage/maria/ha_maria.h:
  Added change_table_ptr() to ensure that external_ref points always to the correct table.
storage/maria/ma_check.c:
  Fixed bug in Duplicate key error printing (now row position is printed correctly)
storage/maria/ma_create.c:
  maria_max_key_length() -> _ma_max_key_length()
storage/maria/ma_info.c:
  Added extern function maria_max_key_length() to calculate the max key length based on current block size.
storage/maria/ma_open.c:
  maria_max_key_length() -> _ma_max_key_length()
storage/maria/maria_def.h:
  maria_max_key_length() -> _ma_max_key_length()
storage/myisam/ha_myisam.cc:
  Added change_table_ptr() to ensure that external_ref points always to the correct table.
  (Not having this caused an assert in the included test)
storage/myisam/ha_myisam.h:
  Added change_table_ptr() to ensure that external_ref points always to the correct table.

2 files changed, 8 insertions, 2 deletions

diff --git a/storage/myisam/ha_myisam.cc b/storage/myisam/ha_myisam.cc
index e6ad635c885..84c16caebe1 100644
--- a/storage/myisam/ha_myisam.cc
+++ b/storage/myisam/ha_myisam.cc
@@ -551,7 +551,6 @@ my_bool mi_killed_in_mariadb(MI_INFO *info)
 
 }
 
-
 ha_myisam::ha_myisam(handlerton *hton, TABLE_SHARE *table_arg)
   :handler(hton, table_arg), file(0),
   int_table_flags(HA_NULL_IN_KEY | HA_CAN_FULLTEXT | HA_CAN_SQL_HANDLER |
@@ -2005,6 +2004,13 @@ int ha_myisam::delete_table(const char *name)
   return mi_delete_table(name);
 }
 
+void ha_myisam::change_table_ptr(TABLE *table_arg, TABLE_SHARE *share)
+{
+  handler::change_table_ptr(table_arg, share);
+  if (file)
+    file->external_ref= table_arg;
+}
+
 
 int ha_myisam::external_lock(THD *thd, int lock_type)
 {
diff --git a/storage/myisam/ha_myisam.h b/storage/myisam/ha_myisam.h
index f895a5bf449..e25cbee03e6 100644
--- a/storage/myisam/ha_myisam.h
+++ b/storage/myisam/ha_myisam.h
@@ -68,7 +68,7 @@ class ha_myisam: public handler
   uint max_supported_key_length()    const { return HA_MAX_KEY_LENGTH; }
   uint max_supported_key_part_length() const { return HA_MAX_KEY_LENGTH; }
   uint checksum() const;
-
+  void change_table_ptr(TABLE *table_arg, TABLE_SHARE *share);
   int open(const char *name, int mode, uint test_if_locked);
   int close(void);
   int write_row(uchar * buf);