MDEV-9021: MYSQLD SEGFAULTS WHEN BUILT USING --WITH-MAX-INDEXES=128

The bitmap implementation defines two template Bitmap classes. One
optimized for 64-bit (default) wide bitmaps while the other is used for
all other widths.

In order to optimize the computations, Bitmap<64> class has defined its
own member functions for bitmap operations, the other one, however,
relies on mysys' bitmap implementation (mysys/my_bitmap.c).

Issue 1:
In case of non 64-bit Bitmap class, intersect() wrongly reset the
received bitmap while initialising a new local bitmap structure
(bitmap_init() clears the bitmap buffer) thus, the received bitmap was
getting cleared.

Fixed by initializing the local bitmap structure by using a temporary
buffer and later copying the received bitmap to the initialised bitmap
structure.

Issue 2:
The non 64-bit Bitmap class had the Iterator missing which caused
compilation failure.

Also added a cmake variable to hold the MAX_INDEXES value when supplied
from the command prompt. (eg. cmake .. -DMAX_INDEXES=128U). Checks have
been put in place to trigger build failure if MAX_INDEXES value is
greater than 128.

Test modifications:
* Introduced include/have_max_indexes_[64|128].inc to facilitate
skipping of tests for which the output differs with different
MAX_INDEXES.

* Introduced include/max_indexes.inc which would get modified by cmake
to reflect the MAX_INDEXES value used to build the server. This file
simply sets an mtr variable '$max_indexes' to show the MAX_INDEXES
value, which will then be consumed by the above introduced include file.

* Some tests (portions), dependent on MAX_INDEXES value, have been moved
to separate test files.

1 files changed, 1 insertions, 0 deletions

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 860426c013a..513f76a06f3 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -5214,6 +5214,7 @@ bool prepare_search_best_index_intersect(PARAM *param,
     return 1;
 
   bzero(init, sizeof(*init));
+  init->filtered_scans.init();
   init->common_info= common;
   init->cost= cutoff_cost;