SQLite

  int nField = 0;    /* Number of fields seen in the pKey1 record */
  int rc = 0;
  const unsigned char *aKey1 = (const unsigned char *)pKey1;
  KeyInfo *pKeyInfo;
  Mem mem1;

  pKeyInfo = pPKey2->pKeyInfo;

  mem1.enc = pKeyInfo->enc;
  mem1.db = pKeyInfo->db;
  /* mem1.flags = 0;  // Will be initialized by sqlite3VdbeSerialGet() */
  VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */

  /* Compilers may complain that mem1.u.i is potentially uninitialized.
  ** We could initialize it, as shown here, to silence those complaints.
  ** But in fact, mem1.u.i will never actually be used uninitialized, and doing 
  ** the unnecessary initialization has a measurable negative performance
  ** impact, since this routine is a very high runner.  And so, we choose
  ** to ignore the compiler warnings and leave this variable uninitialized.
  */
  /*  mem1.u.i = 0;  // not needed, here to silence compiler warning */
  
  idx1 = getVarint32(aKey1, szHdr1);
  if( pKeyInfo->db==0 ) goto debugCompareEnd;
  d1 = szHdr1;
  assert( pKeyInfo->nField+pKeyInfo->nXField>=pPKey2->nField || CORRUPT_DB );
  assert( pKeyInfo->aSortOrder!=0 );
  assert( pKeyInfo->nField>0 );
  assert( idx1<=szHdr1 || CORRUPT_DB );
  do{
    u32 serial_type1;

  /* rc==0 here means that one of the keys ran out of fields and
  ** all the fields up to that point were equal. Return the default_rc
  ** value.  */
  rc = pPKey2->default_rc;

debugCompareEnd:
  /* Verify that the total number of columns in the record does not
  ** exceed pKeyInfo->nField + pKeyInfo->nXField.  This is an assumption
  ** that was made by sqlite3VdbeFindCompare() and if it is wrong then
  ** comparison results can be invalid.  Ticket [f97c4637102a3ae72b].
  */
  while( idx1<szHdr1 ){
    u32 serial_type1;
    idx1 += getVarint32( aKey1+idx1, serial_type1);
    nField++;
  }
  assert( nField <= pKeyInfo->nField + pKeyInfo->nXField || CORRUPT_DB );

  if( pKeyInfo->db==0 ) return 1;
  if( desiredResult==0 && rc==0 ) return 1;
  if( desiredResult<0 && rc<0 ) return 1;
  if( desiredResult>0 && rc>0 ) return 1;
  if( CORRUPT_DB ) return 1;
  if( pKeyInfo->db->mallocFailed ) return 1;
  return 0;
}