Commit 0b72b7f0 authored by unknown's avatar unknown
Browse files

Bug #26642: create index corrupts table definition in .frm 

Thanks to Martin Friebe for finding and submitting a fix for this bug!

A table with maximum number of key segments and maximum length key name
would have a corrupted .frm file, due to an incorrect calculation of the
complete key length.  Now the key length is computed correctly (I hope) :-)

MyISAM would reject a table with the maximum number of keys and the maximum
number of key segments in all keys.  It would allow one less than this total
maximum.  Now MyISAM accepts a table defined with the maximum.  (This is a
very minor issue.)


myisam/mi_open.c:
  change >= to > in a comparison (i.e., error only if key_parts_in_table
  really is greater than MAX_KEY * MAX_KEY_SEG)
mysql-test/r/create.result:
  Add test results for bug #26642 (create index corrupts table definition in .frm)
mysql-test/t/create.test:
  Add test case for bug #26642 (create index corrupts table definition in .frm)
sql/table.cc:
  In create_frm(), fix formula for key_length; it was too small by (keys * 2) bytes
parent e77cdbe2

myisam/mi_open.c

+1 −1
Original line number Diff line number Diff line
@@ -219,7 +219,7 @@ MI_INFO *mi_open(const char *name, int mode, uint open_flags) 


    key_parts+=fulltext_keys*FT_SEGS;

    if (share->base.max_key_length > MI_MAX_KEY_BUFF || keys > MI_MAX_KEY ||

	key_parts >= MI_MAX_KEY * MI_MAX_KEY_SEG)

	key_parts > MI_MAX_KEY * MI_MAX_KEY_SEG)

    {

      DBUG_PRINT("error",("Wrong key info:  Max_key_length: %d  keys: %d  key_parts: %d", share->base.max_key_length, keys, key_parts));

      my_errno=HA_ERR_UNSUPPORTED;

mysql-test/r/create.result

+517 −0

File changed.

Preview size limit exceeded, changes collapsed.

mysql-test/t/create.test

+211 −1

File changed.

Preview size limit exceeded, changes collapsed.

sql/table.cc

+12 −1
Original line number Diff line number Diff line
@@ -1283,7 +1283,18 @@ File create_frm(register my_string name, const char *db, const char *table, 
    fileinfo[3]= (uchar) ha_checktype(create_info->db_type);

    fileinfo[4]=1;

    int2store(fileinfo+6,IO_SIZE);		/* Next block starts here */

    key_length=keys*(7+NAME_LEN+MAX_REF_PARTS*9)+16;

    /*

      For each key (see unireg.cc::pack_keys()):

        8 bytes for the key header

        9 bytes for each key-part (MAX_REF_PARTS)

        NAME_LEN bytes for the name

        1 byte for the NAMES_SEP_CHAR (before the name)

      For all keys:

        6 bytes for the header

        1 byte for the NAMES_SEP_CHAR (after the last name)

        9 extra bytes (padding for safety? alignment?)

    */

    key_length= keys * (8 + MAX_REF_PARTS * 9 + NAME_LEN + 1) + 16;

    length=(ulong) next_io_size((ulong) (IO_SIZE+key_length+reclength));

    int4store(fileinfo+10,length);

    if (key_length > 0xffff) key_length=0xffff;