Merge.

mysql-test/r/join_cache.result

@@ -4964,4 +4964,40 @@ a
 SET SESSION join_cache_level = DEFAULT;
 SET SESSION join_buffer_size = DEFAULT;
 DROP TABLE t1,t2;
+#
+# Bug #802860: crash on join cache + derived + duplicate_weedout 
+#
+SET SESSION optimizer_switch=
+'semijoin=on,materialization=off,firstmatch=off,loosescan=off';
+CREATE TABLE t1 (a int) ;
+INSERT IGNORE INTO t1 VALUES (0), (1), (0);
+CREATE TABLE t2 (a int) ;
+INSERT IGNORE INTO t2 VALUES (0), (3), (0), (2);
+SET SESSION join_cache_level = 0;
+EXPLAIN
+SELECT * FROM (SELECT DISTINCT * FROM t1) t
+WHERE t.a IN (SELECT t2.a FROM t2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	4	Using where; Start temporary
+1	PRIMARY	<derived2>	ref	key0	key0	5	test.t2.a	2	End temporary
+2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	3	Using temporary
+SELECT * FROM (SELECT DISTINCT * FROM t1) t
+WHERE t.a IN (SELECT t2.a FROM t2);
+a
+0
+SET SESSION join_cache_level = 1;
+EXPLAIN
+SELECT * FROM (SELECT DISTINCT * FROM t1) t
+WHERE t.a  IN (SELECT t2.a FROM t2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<derived2>	ALL	key0	NULL	NULL	NULL	3	Start temporary
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	4	Using where; End temporary; Using join buffer (flat, BNL join)
+2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	3	Using temporary
+SELECT * FROM (SELECT DISTINCT * FROM t1) t
+WHERE t.a  IN (SELECT t2.a FROM t2);
+a
+0
+SET SESSION join_cache_level = DEFAULT;
+DROP TABLE t1, t2;
+SET SESSION optimizer_switch=default;
 set @@optimizer_switch=@save_optimizer_switch;

mysql-test/t/join_cache.test

@@ -3100,5 +3100,40 @@ SET SESSION join_buffer_size = DEFAULT;
 
 DROP TABLE t1,t2;
 
+--echo #
+--echo # Bug #802860: crash on join cache + derived + duplicate_weedout 
+--echo #
+
+SET SESSION optimizer_switch=
+  'semijoin=on,materialization=off,firstmatch=off,loosescan=off';
+
+CREATE TABLE t1 (a int) ;
+INSERT IGNORE INTO t1 VALUES (0), (1), (0);
+
+CREATE TABLE t2 (a int) ;
+INSERT IGNORE INTO t2 VALUES (0), (3), (0), (2);
+
+SET SESSION join_cache_level = 0;
+
+EXPLAIN
+SELECT * FROM (SELECT DISTINCT * FROM t1) t
+  WHERE t.a IN (SELECT t2.a FROM t2);
+SELECT * FROM (SELECT DISTINCT * FROM t1) t
+  WHERE t.a IN (SELECT t2.a FROM t2);
+
+SET SESSION join_cache_level = 1;
+
+EXPLAIN
+SELECT * FROM (SELECT DISTINCT * FROM t1) t
+  WHERE t.a  IN (SELECT t2.a FROM t2);
+SELECT * FROM (SELECT DISTINCT * FROM t1) t
+  WHERE t.a  IN (SELECT t2.a FROM t2);
+
+SET SESSION join_cache_level = DEFAULT;
+
+DROP TABLE t1, t2;
+
+SET SESSION optimizer_switch=default;
+
 # this must be the last command in the file
 set @@optimizer_switch=@save_optimizer_switch;

sql/sql_join_cache.cc

@@ -609,8 +609,15 @@ void JOIN_CACHE::create_remaining_fields()
     if (tab->keep_current_rowid)
     {
       copy->str= table->file->ref;
+      if (copy->str)
         copy->length= table->file->ref_length;
-      copy->type= 0;
+      else
+      {
+        /* This may happen only for materialized derived tables and views */
+        copy->length= 0;
+        copy->str= (uchar *) table;
+      } 
+      copy->type= CACHE_ROWID;
       copy->field= 0;
       copy->referenced_field_no= 0;
       length+= copy->length;
@@ -1326,7 +1333,6 @@ uint JOIN_CACHE::write_record_data(uchar * link, bool *is_full)
     Field *field= copy->field;
     if (field && field->maybe_null() && field->is_null())
     {    
-      /* Do not copy a field if its value is null */
       if (copy->referenced_field_no)
         copy->offset= 0;
       continue;              
@@ -1386,6 +1392,18 @@ uint JOIN_CACHE::write_record_data(uchar * link, bool *is_full)
 	cp+= len+2;
         break;
       }
+      case CACHE_ROWID:
+        if (!copy->length)
+	{
+          /*
+            This may happen only for ROWID fields of materialized
+            derived tables and views.
+	  */
+	  TABLE *table= (TABLE *) copy->str;
+          copy->str= table->file->ref;
+          copy->length= table->file->ref_length;
+        }
+        /* fall through */
       default:      
         /* Copy the entire image of the field from the record buffer */
 	memcpy(cp, copy->str, copy->length);
@@ -1455,7 +1473,6 @@ uint JOIN_CACHE::write_record_data(uchar * link, bool *is_full)
   RETURN VALUE
     none
 */
-
 void JOIN_CACHE::reset(bool for_writing)
 {
   pos= buff;

sql/sql_join_cache.h

@@ -16,6 +16,7 @@
 #define CACHE_STRIPPED  2        /* field stripped of trailing spaces */
 #define CACHE_VARSTR1   3        /* short string value (length takes 1 byte) */ 
 #define CACHE_VARSTR2   4        /* long string value (length takes 2 bytes) */
+#define CACHE_ROWID     5        /* ROWID field */
 
 /*
   The CACHE_FIELD structure used to describe fields of records that