database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

Bug#27430 "Crash in subquery code when in PS and table DDL changed after

Browse Source 
PREPARE", review fixes:
- make the patch follow the specification of WL#4166 and remove  
the new error that was originally introduced.
Now the client never gets an error from reprepare, unless it failed.
I.e. even if the statement at hand returns a completely different
result set, this is not considered a server error.
The C API library, that can not handle this situation, was modified to
return a client error.
Added additional test coverage.
This commit is contained in:
kostja@bodhi.(none)
2008-05-20 20:36:26 +04:00
parent 2c0ce2a832
commit 6ae3bca94e
8 changed files with 229 additions and 64 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
libmysql/errmsg.c
View File

@ -84,6 +84,7 @@ const char *client_errors[]=
"This feature is not implemented yet",
"Lost connection to MySQL server at '%s', system error: %d",
"Statement closed indirectly because of a preceeding %s() call",
"The number of columns in the result set differs from the number of bound buffers. You must reset the statement, rebind the result set columns, and execute the statement again",
""
};
@ -149,6 +150,7 @@ const char *client_errors[]=
"This feature is not implemented yet",
"Lost connection to MySQL server at '%s', system error: %d",
"Statement closed indirectly because of a preceeding %s() call",
"The number of columns in the result set differs from the number of bound buffers. You must reset the statement, rebind the result set columns, and execute the statement again",
""
};
@ -212,6 +214,7 @@ const char *client_errors[]=
"This feature is not implemented yet",
"Lost connection to MySQL server at '%s', system error: %d",
"Statement closed indirectly because of a preceeding %s() call",
"The number of columns in the result set differs from the number of bound buffers. You must reset the statement, rebind the result set columns, and execute the statement again",
""
};
#endif

131
libmysql/libmysql.c
View File

@ -1706,6 +1706,7 @@ static my_bool setup_one_fetch_function(MYSQL_BIND *, MYSQL_FIELD *field);
#define RESET_SERVER_SIDE 1
#define RESET_LONG_DATA 2
#define RESET_STORE_RESULT 4
#define RESET_CLEAR_ERROR 8
static my_bool reset_stmt_handle(MYSQL_STMT *stmt, uint flags);
@ -2090,7 +2091,7 @@ mysql_stmt_prepare(MYSQL_STMT *stmt, const char *query, ulong length)
To be removed when all commands will fully support prepared mode.
*/
static unsigned int alloc_stmt_fields(MYSQL_STMT *stmt)
static void alloc_stmt_fields(MYSQL_STMT *stmt)
{
MYSQL_FIELD *fields, *field, *end;
MEM_ROOT *alloc= &stmt->mem_root;
@ -2108,7 +2109,10 @@ static unsigned int alloc_stmt_fields(MYSQL_STMT *stmt)
!(stmt->bind= (MYSQL_BIND *) alloc_root(alloc,
sizeof(MYSQL_BIND) *
stmt->field_count)))
return 0;
{
set_stmt_error(stmt, CR_OUT_OF_MEMORY, unknown_sqlstate, NULL);
return;
}
for (fields= mysql->fields, end= fields+stmt->field_count,
field= stmt->fields;
@ -2127,13 +2131,15 @@ static unsigned int alloc_stmt_fields(MYSQL_STMT *stmt)
field->def = fields->def ? strdup_root(alloc,fields->def): 0;
field->max_length= 0;
}
return stmt->field_count;
}
/*
/**
Update result set columns metadata if it was sent again in
reply to COM_STMT_EXECUTE.
@note If the new field count is different from the original one,
an error is set and no update is performed.
*/
static void update_stmt_fields(MYSQL_STMT *stmt)
@ -2143,7 +2149,22 @@ static void update_stmt_fields(MYSQL_STMT *stmt)
MYSQL_FIELD *stmt_field= stmt->fields;
MYSQL_BIND *my_bind= stmt->bind_result_done ? stmt->bind : 0;
DBUG_ASSERT(stmt->field_count == stmt->mysql->field_count);
if (stmt->field_count != stmt->mysql->field_count)
{
/*
The tables used in the statement were altered,
and the query now returns a different number of columns.
There is no way to continue without reallocating the bind
array:
- if the number of columns increased, mysql_stmt_fetch()
will write beyond allocated memory
- if the number of columns decreased, some user-bound
buffers will be left unassigned without user knowing
that.
*/
set_stmt_error(stmt, CR_NEW_STMT_METADATA, unknown_sqlstate, NULL);
return;
}
for (; field < field_end; ++field, ++stmt_field)
{
@ -2792,6 +2813,50 @@ my_bool STDCALL mysql_stmt_attr_get(MYSQL_STMT *stmt,
}
/**
Update statement result set metadata from with the new field
information sent during statement execute.
@pre mysql->field_count is not zero
@retval TRUE if error: out of memory or the new
result set has a different number of columns
@retval FALSE success
*/
static void reinit_result_set_metadata(MYSQL_STMT *stmt)
{
/* Server has sent result set metadata */
if (stmt->field_count == 0)
{
/*
This is 'SHOW'/'EXPLAIN'-like query. Current implementation of
prepared statements can't send result set metadata for these queries
on prepare stage. Read it now.
*/
alloc_stmt_fields(stmt);
}
else
{
/*
Update result set metadata if it for some reason changed between
prepare and execute, i.e.:
- in case of 'SELECT ?' we don't know column type unless data was
supplied to mysql_stmt_execute, so updated column type is sent
now.
- if data dictionary changed between prepare and execute, for
example a table used in the query was altered.
Note, that now (4.1.3) we always send metadata in reply to
COM_STMT_EXECUTE (even if it is not necessary), so either this or
previous branch always works.
TODO: send metadata only when it's really necessary and add a warning
'Metadata changed' when it's sent twice.
*/
update_stmt_fields(stmt);
}
}
/*
Send placeholders data to server (if there are placeholders)
and execute prepared statement.
@ -2847,7 +2912,7 @@ int STDCALL mysql_stmt_execute(MYSQL_STMT *stmt)
DBUG_RETURN(1);
}
if (reset_stmt_handle(stmt, RESET_STORE_RESULT))
if (reset_stmt_handle(stmt, RESET_STORE_RESULT | RESET_CLEAR_ERROR))
DBUG_RETURN(1);
/*
No need to check for stmt->state: if the statement wasn't
@ -2855,40 +2920,10 @@ int STDCALL mysql_stmt_execute(MYSQL_STMT *stmt)
*/
if (mysql->methods->stmt_execute(stmt))
DBUG_RETURN(1);
stmt->state= MYSQL_STMT_EXECUTE_DONE;
if (mysql->field_count)
{
/* Server has sent result set metadata */
if (stmt->field_count == 0)
{
/*
This is 'SHOW'/'EXPLAIN'-like query. Current implementation of
prepared statements can't send result set metadata for these queries
on prepare stage. Read it now.
*/
alloc_stmt_fields(stmt);
}
else
{
/*
Update result set metadata if it for some reason changed between
prepare and execute, i.e.:
- in case of 'SELECT ?' we don't know column type unless data was
supplied to mysql_stmt_execute, so updated column type is sent
now.
- if data dictionary changed between prepare and execute, for
example a table used in the query was altered.
Note, that now (4.1.3) we always send metadata in reply to
COM_STMT_EXECUTE (even if it is not necessary), so either this or
previous branch always works.
TODO: send metadata only when it's really necessary and add a warning
'Metadata changed' when it's sent twice.
*/
update_stmt_fields(stmt);
}
}
stmt->state= MYSQL_STMT_EXECUTE_DONE;
if (stmt->field_count)
{
reinit_result_set_metadata(stmt);
if (stmt->server_status & SERVER_STATUS_CURSOR_EXISTS)
{
mysql->status= MYSQL_STATUS_READY;
@ -2903,7 +2938,7 @@ int STDCALL mysql_stmt_execute(MYSQL_STMT *stmt)
network or b) is more efficient if all (few) result set rows are
precached on client and server's resources are freed.
*/
DBUG_RETURN(mysql_stmt_store_result(stmt));
mysql_stmt_store_result(stmt);
}
else
{
@ -2912,7 +2947,7 @@ int STDCALL mysql_stmt_execute(MYSQL_STMT *stmt)
stmt->read_row_func= stmt_read_row_unbuffered;
}
}
DBUG_RETURN(0);
DBUG_RETURN(test(stmt->last_errno));
}
@ -4766,6 +4801,12 @@ int STDCALL mysql_stmt_store_result(MYSQL_STMT *stmt)
DBUG_RETURN(1);
}
if (stmt->last_errno)
{
/* An attempt to use an invalid statement handle. */
DBUG_RETURN(1);
}
if (mysql->status == MYSQL_STATUS_READY &&
stmt->server_status & SERVER_STATUS_CURSOR_EXISTS)
{
@ -4973,9 +5014,10 @@ static my_bool reset_stmt_handle(MYSQL_STMT *stmt, uint flags)
stmt->state= MYSQL_STMT_INIT_DONE;
return 1;
}
stmt_clear_error(stmt);
}
}
if (flags & RESET_CLEAR_ERROR)
stmt_clear_error(stmt);
stmt->state= MYSQL_STMT_PREPARE_DONE;
}
return 0;
@ -4986,7 +5028,8 @@ my_bool STDCALL mysql_stmt_free_result(MYSQL_STMT *stmt)
DBUG_ENTER("mysql_stmt_free_result");
/* Free the client side and close the server side cursor if there is one */
DBUG_RETURN(reset_stmt_handle(stmt, RESET_LONG_DATA | RESET_STORE_RESULT));
DBUG_RETURN(reset_stmt_handle(stmt, RESET_LONG_DATA | RESET_STORE_RESULT |
RESET_CLEAR_ERROR));
}
/********************************************************************
@ -5067,7 +5110,9 @@ my_bool STDCALL mysql_stmt_reset(MYSQL_STMT *stmt)
DBUG_RETURN(1);
}
/* Reset the client and server sides of the prepared statement */
DBUG_RETURN(reset_stmt_handle(stmt, RESET_SERVER_SIDE | RESET_LONG_DATA));
DBUG_RETURN(reset_stmt_handle(stmt,
RESET_SERVER_SIDE | RESET_LONG_DATA |
RESET_CLEAR_ERROR));
}
/*