**
**   changesetfuzz INPUT
**   changesetfuzz INPUT SEED N
**
** Argument INPUT must be the name of a file containing a binary changeset.
** In the first form above, this program outputs a human-readable version
** of the same changeset. This is chiefly for debugging.




**
** In the second form, arguments SEED and N must both be integers. In this
** case, this program writes N binary changesets to disk. Each output
** changeset is a slightly modified - "fuzzed" - version of the input. 
** The output changesets are written to files name "INPUT-$n", where $n is 
** an integer between 0 and N-1, inclusive. Output changesets are always
** well-formed. Parameter SEED is used to seed the PRNG - any two 
................................................................................
**      value is appended to all INSERT, DELETE and UPDATE old.* records.
**      An "undefined" is appended to new.* UPDATE records.
**
**  14. A column may be removed from a table, provided that it is not the
**      only PRIMARY KEY column in the table. In this case the corresponding
**      field is removed from all records. In cases where this leaves an UPDATE
**      with no non-PK, non-undefined fields, the entire change is removed.
**
** PATCHSETS
**
** As well as changesets, this program can also dump and fuzz patchsets.
*/

#include "sqlite3.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
................................................................................
  aRec[3] = (iVal>>32) & 0xFF;
  aRec[4] = (iVal>>24) & 0xFF;
  aRec[5] = (iVal>>16) & 0xFF;
  aRec[6] = (iVal>> 8) & 0xFF;
  aRec[7] = (iVal)     & 0xFF;
}






static int fuzzParseHeader(
  FuzzChangeset *pParse,
  u8 **ppHdr, 
  u8 *pEnd, 


  FuzzChangesetGroup **ppGrp
){
  int rc = SQLITE_OK;
  FuzzChangesetGroup *pGrp;
  u8 cHdr = (pParse->bPatchset ? 'P' : 'T');

  assert( pEnd>(*ppHdr) );
  pGrp = (FuzzChangesetGroup*)fuzzMalloc(sizeof(FuzzChangesetGroup));
................................................................................
    pGrp = 0;
  }

  *ppGrp = pGrp;
  return rc;
}








static int fuzzChangeSize(u8 *p, int *pSz){
  u8 eType = p[0];
  switch( eType ){
    case 0x00:                    /* undefined */
    case 0x05:                    /* null */
      *pSz = 1;
      break;
................................................................................

    default:
      return fuzzCorrupt();
  }
  return SQLITE_OK;
}














static int fuzzParseRecord(
  u8 **ppRec,                     /* IN/OUT: Iterator */
  u8 *pEnd,                       /* One byte after end of input data */
  FuzzChangeset *pParse,
  int bPkOnly
){
  int rc = SQLITE_OK;
  FuzzChangesetGroup *pGrp = pParse->apGroup[pParse->nGroup-1];
  int i;
  u8 *p = *ppRec;

  for(i=0; rc==SQLITE_OK && i<pGrp->nCol && p<pEnd; i++){
................................................................................
    rc = fuzzCorrupt();
  }

  *ppRec = p;
  return rc;
}









static int fuzzParseChanges(u8 **ppData, u8 *pEnd, FuzzChangeset *pParse){
  u8 cHdr = (pParse->bPatchset ? 'P' : 'T');
  FuzzChangesetGroup *pGrp = pParse->apGroup[pParse->nGroup-1];
  int rc = SQLITE_OK;
  u8 *p = *ppData;

  pGrp->aChange = p;
................................................................................
  }
  pGrp->szChange = p - pGrp->aChange;

  *ppData = p;
  return rc;
}







static int fuzzParseChangeset(
  u8 *pChangeset,                 /* Buffer containing changeset */
  int nChangeset,                 /* Size of buffer in bytes */
  FuzzChangeset *pParse           /* OUT: Results of parse */
){
  u8 *pEnd = &pChangeset[nChangeset];
  u8 *p = pChangeset;
................................................................................
      rc = fuzzParseChanges(&p, pEnd, pParse);
    }
  }

  return rc;
}













static int fuzzPrintRecord(FuzzChangesetGroup *pGrp, u8 **ppRec, int bPKOnly){
  int rc = SQLITE_OK;
  u8 *p = *ppRec;
  int i;
  const char *zPre = " (";

  for(i=0; i<pGrp->nCol; i++){
................................................................................
  }
  printf(")");

  *ppRec = p;
  return rc;
}





static int fuzzPrintGroup(FuzzChangeset *pParse, FuzzChangesetGroup *pGrp){
  int i;
  u8 *p;

  /* The table header */
  printf("TABLE:  %s nCol=%d aPK=", pGrp->zTab, pGrp->nCol);
  for(i=0; i<pGrp->nCol; i++){
    printf("%d", (int)pGrp->aPK[i]);
................................................................................
      fuzzPrintRecord(pGrp, &p, 0);
    }
    fuzzPrintRecord(pGrp, &p, eType==SQLITE_DELETE && pParse->bPatchset);
    printf("\n");
  }
}











static int fuzzSelectChange(FuzzChangeset *pParse, FuzzChange *pChange){
  int iSub;

  memset(pChange, 0, sizeof(FuzzChange));
  pChange->eType = fuzzRandomInt(FUZZ_COLUMN_DEL) + 1;

  assert( pChange->eType==FUZZ_VALUE_SUB
................................................................................
      }
    }
  }

  return SQLITE_OK;
}





static int fuzzCopyChange(
  FuzzChangeset *pParse,
  int iGrp,
  FuzzChange *pFuzz,
  u8 **pp, u8 **ppOut             /* IN/OUT: Input and output pointers */
){
  int bPS = pParse->bPatchset;
................................................................................

  *pp = p;
  *ppOut = pOut;
  pFuzz->iCurrent += (eType==SQLITE_UPDATE || pFuzz->eType!=FUZZ_CHANGE_FIELD);
  return SQLITE_OK;
}








static int fuzzDoOneFuzz(
  const char *zOut,               /* Filename to write modified changeset to */
  u8 *pBuf,                       /* Buffer to use for modified changeset */
  FuzzChangeset *pParse           /* Parse of input changeset */
){
  FuzzChange change;
  int iGrp;

**
**   changesetfuzz INPUT
**   changesetfuzz INPUT SEED N
**
** Argument INPUT must be the name of a file containing a binary changeset.
** In the first form above, this program outputs a human-readable version
** of the same changeset. This is chiefly for debugging.
**
** As well as changesets, this program can also dump and fuzz patchsets.
** The term "changeset" is used for both patchsets and changesets from this
** point on.
**
** In the second form, arguments SEED and N must both be integers. In this
** case, this program writes N binary changesets to disk. Each output
** changeset is a slightly modified - "fuzzed" - version of the input. 
** The output changesets are written to files name "INPUT-$n", where $n is 
** an integer between 0 and N-1, inclusive. Output changesets are always
** well-formed. Parameter SEED is used to seed the PRNG - any two 
................................................................................
**      value is appended to all INSERT, DELETE and UPDATE old.* records.
**      An "undefined" is appended to new.* UPDATE records.
**
**  14. A column may be removed from a table, provided that it is not the
**      only PRIMARY KEY column in the table. In this case the corresponding
**      field is removed from all records. In cases where this leaves an UPDATE
**      with no non-PK, non-undefined fields, the entire change is removed.




*/

#include "sqlite3.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
................................................................................
  aRec[3] = (iVal>>32) & 0xFF;
  aRec[4] = (iVal>>24) & 0xFF;
  aRec[5] = (iVal>>16) & 0xFF;
  aRec[6] = (iVal>> 8) & 0xFF;
  aRec[7] = (iVal)     & 0xFF;
}

/*
** Parse a single table-header from the input. Allocate a new change-group
** object with the results. Return SQLITE_OK if successful, or an error code
** otherwise.
*/
static int fuzzParseHeader(
  FuzzChangeset *pParse,          /* Changeset parse object */


  u8 **ppHdr,                     /* IN/OUT: Iterator */
  u8 *pEnd,                       /* 1 byte past EOF */
  FuzzChangesetGroup **ppGrp      /* OUT: New change-group object */
){
  int rc = SQLITE_OK;
  FuzzChangesetGroup *pGrp;
  u8 cHdr = (pParse->bPatchset ? 'P' : 'T');

  assert( pEnd>(*ppHdr) );
  pGrp = (FuzzChangesetGroup*)fuzzMalloc(sizeof(FuzzChangesetGroup));
................................................................................
    pGrp = 0;
  }

  *ppGrp = pGrp;
  return rc;
}

/*
** Argument p points to a buffer containing a single changeset-record value. 
** This function attempts to determine the size of the value in bytes. If
** successful, it sets (*pSz) to the size and returns SQLITE_OK. Or, if the
** buffer does not contain a valid value, SQLITE_CORRUPT is returned and
** the final value of (*pSz) is undefined.
*/
static int fuzzChangeSize(u8 *p, int *pSz){
  u8 eType = p[0];
  switch( eType ){
    case 0x00:                    /* undefined */
    case 0x05:                    /* null */
      *pSz = 1;
      break;
................................................................................

    default:
      return fuzzCorrupt();
  }
  return SQLITE_OK;
}

/*
** When this function is called, (*ppRec) points to the start of a 
** record in a changeset being parsed. This function adds entries
** to the pParse->apVal[] array for all values and advances (*ppRec) 
** to one byte past the end of the record. Argument pEnd points to
** one byte past the end of the input changeset.
**
** Argument bPkOnly is true if the record being parsed is part of
** a DELETE record in a patchset. In this case, all non-primary-key
** fields have been omitted from the record.
**
** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
*/
static int fuzzParseRecord(
  u8 **ppRec,                     /* IN/OUT: Iterator */
  u8 *pEnd,                       /* One byte after end of input data */
  FuzzChangeset *pParse,          /* Changeset parse context */
  int bPkOnly                     /* True if non-PK fields omitted */
){
  int rc = SQLITE_OK;
  FuzzChangesetGroup *pGrp = pParse->apGroup[pParse->nGroup-1];
  int i;
  u8 *p = *ppRec;

  for(i=0; rc==SQLITE_OK && i<pGrp->nCol && p<pEnd; i++){
................................................................................
    rc = fuzzCorrupt();
  }

  *ppRec = p;
  return rc;
}

/*
** Parse the array of changes starting at (*ppData) and add entries for
** all values to the pParse->apVal[] array. Argument pEnd points to one byte
** past the end of the input changeset. If successful, set (*ppData) to point
** to one byte past the end of the change array and return SQLITE_OK.
** Otherwise, return an SQLite error code. The final value of (*ppData) is
** undefined in this case.
*/
static int fuzzParseChanges(u8 **ppData, u8 *pEnd, FuzzChangeset *pParse){
  u8 cHdr = (pParse->bPatchset ? 'P' : 'T');
  FuzzChangesetGroup *pGrp = pParse->apGroup[pParse->nGroup-1];
  int rc = SQLITE_OK;
  u8 *p = *ppData;

  pGrp->aChange = p;
................................................................................
  }
  pGrp->szChange = p - pGrp->aChange;

  *ppData = p;
  return rc;
}

/*
** Parse the changeset stored in buffer pChangeset (nChangeset bytes in
** size). If successful, write the results into (*pParse) and return
** SQLITE_OK. Or, if an error occurs, return an SQLite error code. The
** final state of (*pParse) is undefined in this case.
*/
static int fuzzParseChangeset(
  u8 *pChangeset,                 /* Buffer containing changeset */
  int nChangeset,                 /* Size of buffer in bytes */
  FuzzChangeset *pParse           /* OUT: Results of parse */
){
  u8 *pEnd = &pChangeset[nChangeset];
  u8 *p = pChangeset;
................................................................................
      rc = fuzzParseChanges(&p, pEnd, pParse);
    }
  }

  return rc;
}

/*
** When this function is called, (*ppRec) points to the first byte of
** a record that is part of change-group pGrp. This function attempts
** to output a human-readable version of the record to stdout and advance
** (*ppRec) to point to the first byte past the end of the record before
** returning. If successful, SQLITE_OK is returned. Otherwise, an SQLite
** error code.
**
** If parameter bPkOnly is non-zero, then all non-primary-key fields have
** been omitted from the record. This occurs for records that are part
** of DELETE changes in patchsets.
*/
static int fuzzPrintRecord(FuzzChangesetGroup *pGrp, u8 **ppRec, int bPKOnly){
  int rc = SQLITE_OK;
  u8 *p = *ppRec;
  int i;
  const char *zPre = " (";

  for(i=0; i<pGrp->nCol; i++){
................................................................................
  }
  printf(")");

  *ppRec = p;
  return rc;
}

/*
** Print a human-readable version of the table-header and all changes in the
** change-group passed as the second argument.
*/
static void fuzzPrintGroup(FuzzChangeset *pParse, FuzzChangesetGroup *pGrp){
  int i;
  u8 *p;

  /* The table header */
  printf("TABLE:  %s nCol=%d aPK=", pGrp->zTab, pGrp->nCol);
  for(i=0; i<pGrp->nCol; i++){
    printf("%d", (int)pGrp->aPK[i]);
................................................................................
      fuzzPrintRecord(pGrp, &p, 0);
    }
    fuzzPrintRecord(pGrp, &p, eType==SQLITE_DELETE && pParse->bPatchset);
    printf("\n");
  }
}

/*
** Initialize the object passed as the second parameter with details
** of the change that will be attempted (type of change, to which part of the
** changeset it applies etc.). If successful, return SQLITE_OK. Or, if an
** error occurs, return an SQLite error code. 
**
** If a negative value is returned, then the selected change would have
** produced a non-well-formed changeset. In this case the caller should
** call this function again.
*/
static int fuzzSelectChange(FuzzChangeset *pParse, FuzzChange *pChange){
  int iSub;

  memset(pChange, 0, sizeof(FuzzChange));
  pChange->eType = fuzzRandomInt(FUZZ_COLUMN_DEL) + 1;

  assert( pChange->eType==FUZZ_VALUE_SUB
................................................................................
      }
    }
  }

  return SQLITE_OK;
}

/*
** Copy a single change from the input to the output changeset, making
** any modifications specified by (*pFuzz).
*/
static int fuzzCopyChange(
  FuzzChangeset *pParse,
  int iGrp,
  FuzzChange *pFuzz,
  u8 **pp, u8 **ppOut             /* IN/OUT: Input and output pointers */
){
  int bPS = pParse->bPatchset;
................................................................................

  *pp = p;
  *ppOut = pOut;
  pFuzz->iCurrent += (eType==SQLITE_UPDATE || pFuzz->eType!=FUZZ_CHANGE_FIELD);
  return SQLITE_OK;
}

/*
** Fuzz the changeset parsed into object pParse and write the results 
** to file zOut on disk. Argument pBuf points to a buffer that is guaranteed
** to be large enough to hold the fuzzed changeset.
**
** Return SQLITE_OK if successful, or an SQLite error code if an error occurs.
*/
static int fuzzDoOneFuzz(
  const char *zOut,               /* Filename to write modified changeset to */
  u8 *pBuf,                       /* Buffer to use for modified changeset */
  FuzzChangeset *pParse           /* Parse of input changeset */
){
  FuzzChange change;
  int iGrp;