[mdb-dev] Slight fix for table.c

[Mike P. <mj...@fi...>]

Hi all,

I've been running into some segfaults with the CVS version and a JET3 
database, and discovered a bug in read_pg_if_n in table.c.

I've done so much futzing I can't be fussed to make a diff, but the change is 
easy enough - if you insert the bit between the 'MJP' comments as shown below, 
this will avoid the situation where cur_pos is outside the current page size, 
and hence causes 'half' to go negative.

It's worked for me - I don't know how clean it is, or whether it's masking 
another error further up the line.

As an aside, I've also got support for REPID's if anyone is interested - 
again, a couple of simple changes.

Does anyone know if anything is making it into CVS, or has the maintainer gone 
awol ??

-------

guint16
read_pg_if_n(MdbHandle *mdb, void *buf, int *cur_pos, int len)
{
         // MJP

         while (*cur_pos > mdb->fmt->pg_size)
         {
            mdb_read_pg(mdb, mdb_get_int32(mdb->pg_buf,4));
            *cur_pos = *cur_pos - mdb->fmt->pg_size;
         }

	// MJP

         if (*cur_pos + len < mdb->fmt->pg_size) {
                 memcpy(buf, &mdb->pg_buf[*cur_pos], len);
                 return 0;
         } else {
                 int half = mdb->fmt->pg_size - *cur_pos;
//printf ("curpos = %d, pg_size = %d, len = %d, half = %d\n", *cur_pos, 
mdb->fmt->pg_size, len, half);
                 memcpy(buf, &mdb->pg_buf[*cur_pos], half);
                 mdb_read_pg(mdb, mdb_get_int32(mdb->pg_buf,4));
                 memcpy(buf + half, &mdb->pg_buf[8], len - half);
                 *cur_pos = 8 - half;
                 return 1;
         }
}


-- 
Cheers,

Mike

mj...@fi...                             http://www.filmsat59.com
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