Bug #38795: Automatic search depth and nested join's results in server crash

      
The greedy optimizer tracks the current level of nested joins and the position
inside these by setting and maintaining a state that's global for the whole FROM
clause.
This state was correctly maintained inside the selection of the next partial plan
table (in best_extension_by_limited_search()). 
greedy_search() also moves the current position by adding the last partial match 
table when there's not enough tables in the partial plan found by 
best_extension_by_limited_search().
This may require update of the global state variables that describe the current
position in the plan if the last table placed by greedy_search is not a top-level 
join table.
Fixed by updating the state after placing the partial plan table in greedy_search()
in the same way this is done on entering the best_extension_by_limited_search().
Fixed the signature of the function called to update the state : 
check_interleaving_with_nj

mysql-test/r/greedy_optimizer.result:
  Bug #38795: test case
mysql-test/t/greedy_optimizer.test:
  Bug #38795: test case
sql/sql_select.cc:
  Bug #38795: correctly update current position when placing
  the next partial plan table in greedy_search().

1 files changed, 77 insertions, 0 deletions

diff --git a/mysql-test/r/greedy_optimizer.result b/mysql-test/r/greedy_optimizer.result
index 1da49fbedb0..534038ee626 100644
--- a/mysql-test/r/greedy_optimizer.result
+++ b/mysql-test/r/greedy_optimizer.result
@@ -655,3 +655,80 @@ show status like 'Last_query_cost';
 Variable_name	Value
 Last_query_cost	794.837037
 drop table t1,t2,t3,t4,t5,t6,t7;
+CREATE TABLE t1 (a int, b int, d int, i int);
+INSERT INTO t1 VALUES (1,1,1,1);
+CREATE TABLE t2 (b int, c int, j int);
+INSERT INTO t2 VALUES (1,1,1);
+CREATE TABLE t2_1 (j int);
+INSERT INTO t2_1 VALUES (1);
+CREATE TABLE t3 (c int, f int);
+INSERT INTO t3 VALUES (1,1);
+CREATE TABLE t3_1 (f int);
+INSERT INTO t3_1 VALUES (1);
+CREATE TABLE t4 (d int, e int, k int);
+INSERT INTO t4 VALUES (1,1,1);
+CREATE TABLE t4_1 (k int);
+INSERT INTO t4_1 VALUES (1);
+CREATE TABLE t5 (g int, d int, h int, l int);
+INSERT INTO t5 VALUES (1,1,1,1);
+CREATE TABLE t5_1 (l int);
+INSERT INTO t5_1 VALUES (1);
+SET optimizer_search_depth = 3;
+SELECT 1
+FROM t1
+LEFT JOIN (
+t2 JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+t4 JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SELECT 1
+FROM t1
+LEFT JOIN (
+t2 LEFT JOIN (t3 JOIN t3_1 ON t3.f = t3_1.f) ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+t4 JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SELECT 1
+FROM t1
+LEFT JOIN (
+(t2 JOIN t2_1 ON t2.j = t2_1.j) JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+t4 JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SELECT 1
+FROM t1
+LEFT JOIN (
+t2 JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+(t4 JOIN t4_1 ON t4.k = t4_1.k) LEFT JOIN t5 ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SELECT 1
+FROM t1
+LEFT JOIN (
+t2 JOIN t3 ON t3.c = t2.c
+) ON t2.b = t1.b
+LEFT JOIN (
+t4 LEFT JOIN (t5 JOIN t5_1 ON t5.l = t5_1.l) ON t5.d = t4.d
+) ON t4.d = t1.d
+;
+1
+1
+SET optimizer_search_depth = DEFAULT;
+DROP TABLE t1,t2,t2_1,t3,t3_1,t4,t4_1,t5,t5_1;
+End of 5.0 tests