/ Check-in [486949fc]
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Overview
Comment:Improvement to a comment. No changes to code.
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SHA3-256: 486949fc03706e0056439b52ce60931ea4ce0a65e391da7f6287fe13862de251
User & Date: drh 2017-11-14 03:42:52
Context
2017-11-14
19:34
Add the ability to read from read-only WAL-mode database files as long as the -wal and -shm files are present on disk. check-in: 00ec95fc user: drh tags: trunk
03:42
Improvement to a comment. No changes to code. Closed-Leaf check-in: 486949fc user: drh tags: readonly-wal-recovery
2017-11-13
05:51
Remove some branches in walTryBeginRead() that were added by check-in [ce5d13c2de] but became unreachable with the addition of logic in check-in [18b26843] that enabled read-only clients to parse the WAL file into a heap-memory WAL-index, thus guaranteeing that the WAL-index header is always available. check-in: 9c6b38b9 user: drh tags: readonly-wal-recovery
Changes
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Changes to src/wal.c.

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    rc = SQLITE_CANTOPEN_BKPT;
  }
  if( pWal->bShmUnreliable ){
    if( rc!=SQLITE_OK ){
      walIndexClose(pWal, 0);
      pWal->bShmUnreliable = 0;
      assert( pWal->nWiData>0 && pWal->apWiData[0]==0 );



      if( rc==SQLITE_IOERR_SHORT_READ ) rc = WAL_RETRY;
    }
    pWal->exclusiveMode = WAL_NORMAL_MODE;
  }

  return rc;
}







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    rc = SQLITE_CANTOPEN_BKPT;
  }
  if( pWal->bShmUnreliable ){
    if( rc!=SQLITE_OK ){
      walIndexClose(pWal, 0);
      pWal->bShmUnreliable = 0;
      assert( pWal->nWiData>0 && pWal->apWiData[0]==0 );
      /* walIndexRecover() might have returned SHORT_READ if a concurrent
      ** writer truncated the WAL out from under it.  If that happens, it
      ** indicates that a writer has fixed the SHM file for us, so retry */
      if( rc==SQLITE_IOERR_SHORT_READ ) rc = WAL_RETRY;
    }
    pWal->exclusiveMode = WAL_NORMAL_MODE;
  }

  return rc;
}