Fixed crashing bug in recursive SQL if write to tmp table would fail

This error was discovered while working on
MDEV-30540 Wrong result with IN list length reaching
           IN_PREDICATE_CONVERSION_THRESHOLD

If there is read error from handler::ha_rnd_next() during a recursive
query, st_select_lex_unit::exec_recursive() will crash as it will try to
get the error code from a structure that was deleted by the callee.
The code was using the construct:
   sl->join->exec();
   saved_error=sl->join->error;
This does not work as sl->join was freed by the exec() and sl->join would
be set to 0.
Fixed by having JOIN::exec() return the error code.
The included test case simulates the error in ha_rnd_next(), which causes
a crash without the patch.
scovered whle working on
MDEV-30540 Wrong result with IN list length reaching
           IN_PREDICATE_CONVERSION_THRESHOLD

If there is read error from handler::ha_rnd_next() during a recursive
query, st_select_lex_unit::exec_recursive() will crash as it will try to
get the error code from a structure that was deleted by the callee.
The code was using the construct:
   sl->join->exec();
   saved_error=sl->join->error;
This does not work as sl->join was freed by the exec() and sl->join was
set to 0.
Fixed by having JOIN::exec() return the error code.
The included test case simulates the error in ha_rnd_next(), which causes
a crash without the patch.

2 files changed, 120 insertions, 0 deletions

diff --git a/mysql-test/suite/maria/crash-recursive.result b/mysql-test/suite/maria/crash-recursive.result
new file mode 100644
index 00000000000..998bb9e501b
--- /dev/null
+++ b/mysql-test/suite/maria/crash-recursive.result
@@ -0,0 +1,53 @@
+set @save_big_tables=@@big_tables;
+set big_tables=1;
+Warnings:
+Warning	1287	'@@big_tables' is deprecated and will be removed in a future release
+create table  folks(id int, name char(32), dob date, father int, mother int);
+insert into folks values
+(100, 'Me', '2000-01-01', 20, 30),
+(20, 'Dad', '1970-02-02', 10, 9),
+(30, 'Mom', '1975-03-03', 8, 7),
+(10, 'Grandpa Bill', '1940-04-05', null, null),
+(9, 'Grandma Ann', '1941-10-15', null, null),
+(25, 'Uncle Jim', '1968-11-18', 8, 7),
+(98, 'Sister Amy', '2001-06-20', 20, 30),
+(7, 'Grandma Sally', '1943-08-23', null, 6),
+(8, 'Grandpa Ben', '1940-10-21', null, null),
+(6, 'Grandgrandma Martha', '1923-05-17', null, null),
+(67, 'Cousin Eddie', '1992-02-28', 25, 27),
+(27, 'Auntie Melinda', '1971-03-29', null, null);
+call mtr.add_suppression(".*marked as crashed.*");
+SET @saved_dbug= @@SESSION.debug_dbug;
+SET SESSION debug_dbug="+d,ha_rnd_next_error";
+SET @ha_rnd_next_error_counter=110;
+with recursive
+ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
+w_id, w_name, w_dob, w_father, w_mother)
+as
+(
+select h.*, w.*
+from folks h, folks w,  coupled_ancestors a
+where a.father = h.id AND a.mother = w.id
+union
+select h.*, w.*
+from folks v, folks h, folks w
+where v.name = 'Me' and
+(v.father = h.id AND v.mother= w.id)
+),
+coupled_ancestors (id, name, dob, father, mother)
+as
+(
+select h_id, h_name, h_dob, h_father, h_mother
+from ancestor_couples
+union
+select w_id, w_name, w_dob, w_father, w_mother
+from ancestor_couples
+)
+select h_name, h_dob, w_name, w_dob
+from ancestor_couples;
+ERROR HY000: Table '(temporary)' is marked as crashed and should be repaired
+drop table folks;
+set big_tables=@save_big_tables;
+Warnings:
+Warning	1287	'@@big_tables' is deprecated and will be removed in a future release
+SET @@SESSION.debug_dbug=@saved_dbug;
diff --git a/mysql-test/suite/maria/crash-recursive.test b/mysql-test/suite/maria/crash-recursive.test
new file mode 100644
index 00000000000..1fa18ce85c0
--- /dev/null
+++ b/mysql-test/suite/maria/crash-recursive.test
@@ -0,0 +1,67 @@
+#
+# This test simulates an error in an aria file discovered during a recursive SQL call.
+# The error handling causes used join structures to be deleted, which caused crashes in
+# upper levels when trying to access structures that does not exist anymore
+#
+
+--source include/have_debug_sync.inc
+--source include/not_embedded.inc
+
+set @save_big_tables=@@big_tables;
+set big_tables=1;
+
+create table  folks(id int, name char(32), dob date, father int, mother int);
+
+insert into folks values
+(100, 'Me', '2000-01-01', 20, 30),
+(20, 'Dad', '1970-02-02', 10, 9),
+(30, 'Mom', '1975-03-03', 8, 7),
+(10, 'Grandpa Bill', '1940-04-05', null, null),
+(9, 'Grandma Ann', '1941-10-15', null, null),
+(25, 'Uncle Jim', '1968-11-18', 8, 7),
+(98, 'Sister Amy', '2001-06-20', 20, 30),
+(7, 'Grandma Sally', '1943-08-23', null, 6),
+(8, 'Grandpa Ben', '1940-10-21', null, null),
+(6, 'Grandgrandma Martha', '1923-05-17', null, null),
+(67, 'Cousin Eddie', '1992-02-28', 25, 27),
+(27, 'Auntie Melinda', '1971-03-29', null, null);
+
+
+call mtr.add_suppression(".*marked as crashed.*");
+SET @saved_dbug= @@SESSION.debug_dbug;
+SET SESSION debug_dbug="+d,ha_rnd_next_error";
+SET @ha_rnd_next_error_counter=110;
+
+let q=
+with recursive
+ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
+                 w_id, w_name, w_dob, w_father, w_mother)
+as
+(
+  select h.*, w.*
+    from folks h, folks w,  coupled_ancestors a
+      where a.father = h.id AND a.mother = w.id
+  union
+  select h.*, w.*
+    from folks v, folks h, folks w
+      where v.name = 'Me' and
+            (v.father = h.id AND v.mother= w.id)
+),
+coupled_ancestors (id, name, dob, father, mother)
+as
+(
+  select h_id, h_name, h_dob, h_father, h_mother
+    from ancestor_couples
+  union
+  select w_id, w_name, w_dob, w_father, w_mother
+    from ancestor_couples
+)
+select h_name, h_dob, w_name, w_dob
+  from ancestor_couples;
+
+--error ER_CRASHED_ON_USAGE
+eval $q;
+drop table folks;
+
+set big_tables=@save_big_tables;
+SET @@SESSION.debug_dbug=@saved_dbug;
\ No newline at end of file