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Check-in [e0af9a9040]
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Overview
Comment:The BLOB returned by sqlite3VdbeMemFromBtree() does not need to be zero-terminated.
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SHA3-256: e0af9a9040768adf8bba42a8780adeb6304bc442afb1f35d239d019db1624f40
User & Date: drh 2017-09-20 18:07:50.056
References
2017-09-22
12:52
Partial backout of check-in [e0af9a904076]. It turns out we do need some extra space at the end of the record blob as an overrun area to use when decoding a maliciously malformed record. (check-in: 403b88a894 user: drh tags: trunk)
Context
2017-09-22
12:52
Partial backout of check-in [e0af9a904076]. It turns out we do need some extra space at the end of the record blob as an overrun area to use when decoding a maliciously malformed record. (check-in: 403b88a894 user: drh tags: trunk)
2017-09-20
18:47
Size and performance optimization on sqlite3VdbeMemGrow(). (check-in: 4b3f7eacb8 user: drh tags: trunk)
18:07
The BLOB returned by sqlite3VdbeMemFromBtree() does not need to be zero-terminated. (check-in: e0af9a9040 user: drh tags: trunk)
17:49
Small size and performance optimization in the bytecode engine. (check-in: 3b3e32d4cd user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/vdbemem.c.
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  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
  u32 offset,       /* Offset from the start of data to return bytes from. */
  u32 amt,          /* Number of bytes to return. */
  Mem *pMem         /* OUT: Return data in this Mem structure. */
){
  int rc;
  pMem->flags = MEM_Null;
  if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+2)) ){
    rc = sqlite3BtreePayload(pCur, offset, amt, pMem->z);
    if( rc==SQLITE_OK ){
      pMem->z[amt] = 0;
      pMem->z[amt+1] = 0;
      pMem->flags = MEM_Blob|MEM_Term;
      pMem->n = (int)amt;
    }else{
      sqlite3VdbeMemRelease(pMem);
    }
  }
  return rc;
}








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  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
  u32 offset,       /* Offset from the start of data to return bytes from. */
  u32 amt,          /* Number of bytes to return. */
  Mem *pMem         /* OUT: Return data in this Mem structure. */
){
  int rc;
  pMem->flags = MEM_Null;
  if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt)) ){
    rc = sqlite3BtreePayload(pCur, offset, amt, pMem->z);
    if( rc==SQLITE_OK ){


      pMem->flags = MEM_Blob;
      pMem->n = (int)amt;
    }else{
      sqlite3VdbeMemRelease(pMem);
    }
  }
  return rc;
}
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