Fixed bug with indexed NULL column <=> NULL

Fix for Mac OS X shutdown

mysql-test/mysql-test-run.sh

@@ -249,6 +249,7 @@ SLAVE_MYPID="$MYRUN_DIR/mysqld-slave.pid"
 SLAVE_MYLOG="$MYSQL_TEST_DIR/var/log/mysqld-slave.log"
 SLAVE_MYERR="$MYSQL_TEST_DIR/var/log/mysqld-slave.err"
 
+CLIENT_MYLOG="$MYSQL_TEST_DIR/var/log/client.log"
 SMALL_SERVER="-O key_buffer_size=1M -O sort_buffer=256K -O max_heap_table_size=1M"
 
 export MASTER_MYPORT
@@ -344,7 +345,7 @@ SLAVE_MYSQLD=$MYSQLD #this can be changed later if we are doing gcov
 #--
 wait_for_server_start ()
 {
-   $MYSQLADMIN --no-defaults -u $DBUSER --silent -O connect_timeout=10 -w3 --host=$hostname --port=$1  ping >/dev/null 2>&1
+   $MYSQLADMIN --no-defaults -u $DBUSER --silent -O connect_timeout=10 -w3 --host=$hostname --port=$1  ping >> $CLIENT_MYLOG 2>&1
    exit_code=$?
    if [ $exit_code != 0 ]; then
 	echo "Error: Could not start $2, exit code $exit_code";

mysql-test/r/null_key.result

@@ -126,3 +126,20 @@ order_id	product_id	product_type
 3d7ce39b5d4b3e3d22aaafe9b633de51	5880836	3
 id	id
 id	id
+id	id2
+NULL	0
+1	1
+id	id2
+NULL	0
+id	id2
+NULL	0
+1	1
+id	id2
+NULL	0
+1	1
+id	id2
+1	1
+id	id2
+1	1
+id	id2
+1	1

mysql-test/t/null_key.test

@@ -135,3 +135,24 @@ select * from t1, t2 where t1.id = t2.id;
 alter table t1 add key id (id);
 select * from t1, t2 where t1.id = t2.id;
 drop table t1,t2;
+
+#
+# Check bug when doing <=> NULL on an indexed null field
+#
+
+create table t1 (
+  id  integer,
+  id2 integer not null,
+  index (id),
+  index (id2)
+);
+insert into t1 values(null,null),(1,1);
+select * from t1;
+select * from t1 where id <=> null;
+select * from t1 where id <=> null or id > 0;
+select * from t1 where id is null or id > 0;
+select * from t1 where id2 <=> null or id2 > 0;
+select * from t1 where id2 is null or id2 > 0;
+delete from t1 where id <=> NULL;
+select * from t1;
+drop table t1;

sql/mysqld.cc

@@ -739,7 +739,11 @@ static sig_handler print_signal_warning(int sig)
 void unireg_end(int signal_number __attribute__((unused)))
 {
   clean_up();
+#ifdef SIGNALS_DONT_BREAK_READ
+  exit(0);
+#else
   pthread_exit(0);				// Exit is in main thread
+#endif
 }
 
 

sql/opt_range.cc

@@ -931,8 +931,11 @@ get_mm_leaf(Field *field,KEY_PART *key_part,
     if (!(res= value->val_str(&tmp)))
       DBUG_RETURN(&null_element);
 
-    // Check if this was a function. This should have be optimized away
-    // in the sql_select.cc
+    /*
+      TODO:
+      Check if this was a function. This should have be optimized away
+      in the sql_select.cc
+    */
     if (res != &tmp)
     {
       tmp.copy(*res);				// Get own copy
@@ -1011,8 +1014,10 @@ get_mm_leaf(Field *field,KEY_PART *key_part,
       type != Item_func::EQUAL_FUNC)
     DBUG_RETURN(0);				// Can't optimize this
 
-  /* We can't always use indexes when comparing a string index to a number */
-  /* cmp_type() is checked to allow compare of dates to numbers */
+  /*
+    We can't always use indexes when comparing a string index to a number
+    cmp_type() is checked to allow compare of dates to numbers
+  */
   if (field->result_type() == STRING_RESULT &&
       value->result_type() != STRING_RESULT &&
       field->cmp_type() != value->result_type())
@@ -1020,6 +1025,7 @@ get_mm_leaf(Field *field,KEY_PART *key_part,
 
   if (value->save_in_field(field))
   {
+    /* This happens when we try to insert a NULL field in a not null column */
     if (type == Item_func::EQUAL_FUNC)
     {
       /* convert column_name <=> NULL -> column_name IS NULL */
@@ -1029,14 +1035,14 @@ get_mm_leaf(Field *field,KEY_PART *key_part,
       *str = 1;
       DBUG_RETURN(new SEL_ARG(field,str,str));
     }
-    DBUG_RETURN(&null_element);			// NULL is never true
+    DBUG_RETURN(&null_element);			// cmp with NULL is never true
   }
   // Get local copy of key
   char *str= (char*) sql_alloc(key_part->part_length+maybe_null);
   if (!str)
     DBUG_RETURN(0);
   if (maybe_null)
-    *str=0;					// Not NULL
+    *str= (char) field->is_real_null();		// Set to 1 if null
   field->get_key_image(str+maybe_null,key_part->part_length);
   if (!(tree=new SEL_ARG(field,str,str)))
     DBUG_RETURN(0);