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A fix and a test case for Bug#9520 "SELECT DISTINCT crashes server

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with cursor". The patch refactors do_select/sub_select
functions, which implement the nested loop algorithm, and reuses them to
fetch rows for cursors as well.
Pushing with view.test failing (--ps-protocol).
This commit is contained in:
konstantin@mysql.com
2005-04-30 09:54:35 +04:00
parent f35c1a1874
commit 6040b0abf6
4 changed files with 456 additions and 360 deletions
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2
sql/sql_prepare.cc
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@ -2223,7 +2223,7 @@ void mysql_stmt_fetch(THD *thd, char *packet, uint packet_length)
my_pthread_setprio(pthread_self(), QUERY_PRIOR);
thd->protocol= &thd->protocol_prep; // Switch to binary protocol
(void) stmt->cursor->fetch(num_rows);
stmt->cursor->fetch(num_rows);
thd->protocol= &thd->protocol_simple; // Use normal protocol
if (!(specialflag & SPECIAL_NO_PRIOR))

742
sql/sql_select.cc
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File diff suppressed because it is too large Load Diff

18
sql/sql_select.h
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@ -91,7 +91,15 @@ enum join_type { JT_UNKNOWN,JT_SYSTEM,JT_CONST,JT_EQ_REF,JT_REF,JT_MAYBE_REF,
class JOIN;
typedef int (*Next_select_func)(JOIN *,struct st_join_table *,bool);
enum enum_nested_loop_state
{
NESTED_LOOP_KILLED= -2, NESTED_LOOP_ERROR= -1,
NESTED_LOOP_OK= 0, NESTED_LOOP_NO_MORE_ROWS= 1,
NESTED_LOOP_QUERY_LIMIT= 3, NESTED_LOOP_CURSOR_LIMIT= 4
};
typedef enum_nested_loop_state
(*Next_select_func)(JOIN *, struct st_join_table *, bool);
typedef int (*Read_record_func)(struct st_join_table *tab);
@ -162,6 +170,11 @@ class JOIN :public Sql_alloc
uint send_group_parts;
bool sort_and_group,first_record,full_join,group, no_field_update;
bool do_send_rows;
/*
TRUE when we want to resume nested loop iterations when
fetching data from a cursor
*/
bool resume_nested_loop;
table_map const_table_map,found_const_table_map,outer_join;
ha_rows send_records,found_records,examined_rows,row_limit, select_limit;
/*
@ -263,6 +276,7 @@ class JOIN :public Sql_alloc
sort_and_group= 0;
first_record= 0;
do_send_rows= 1;
resume_nested_loop= FALSE;
send_records= 0;
found_records= 0;
fetch_limit= HA_POS_ERROR;
@ -374,7 +388,7 @@ public:
void reset_thd(THD *thd);
int open(JOIN *join);
int fetch(ulong num_rows);
void fetch(ulong num_rows);
void reset() { join= 0; }
bool is_open() const { return join != 0; }
void close();

54
tests/mysql_client_test.c
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@ -12854,6 +12854,59 @@ static void test_bug9159()
myquery(rc);
}
/* Crash when opening a cursor to a query with DISTICNT and no key */
static void test_bug9520()
{
MYSQL_STMT *stmt;
MYSQL_BIND bind[1];
char a[6];
ulong a_len;
int rc, row_count= 0;
myheader("test_bug9520");
mysql_query(mysql, "drop table if exists t1");
mysql_query(mysql, "create table t1 (a char(5), b char(5), c char(5),"
" primary key (a, b, c))");
rc= mysql_query(mysql, "insert into t1 values ('x', 'y', 'z'), "
" ('a', 'b', 'c'), ('k', 'l', 'm')");
myquery(rc);
stmt= open_cursor("select distinct b from t1");
/*
Not crashes with:
stmt= open_cursor("select distinct a from t1");
*/
rc= mysql_stmt_execute(stmt);
check_execute(stmt, rc);
bzero(bind, sizeof(bind));
bind[0].buffer_type= MYSQL_TYPE_STRING;
bind[0].buffer= (char*) a;
bind[0].buffer_length= sizeof(a);
bind[0].length= &a_len;
mysql_stmt_bind_result(stmt, bind);
while (!(rc= mysql_stmt_fetch(stmt)))
row_count++;
DIE_UNLESS(rc == MYSQL_NO_DATA);
printf("Fetched %d rows\n", row_count);
DBUG_ASSERT(row_count == 3);
mysql_stmt_close(stmt);
rc= mysql_query(mysql, "drop table t1");
myquery(rc);
}
/*
Read and parse arguments and MySQL options from my.cnf
*/
@ -13079,6 +13132,7 @@ static struct my_tests_st my_tests[]= {
{ "test_bug8722", test_bug8722 },
{ "test_bug8880", test_bug8880 },
{ "test_bug9159", test_bug9159 },
{ "test_bug9520", test_bug9520 },
{ 0, 0 }
};