Summary:
If the corruption of a table file is done before flushing, then db manifest may record the checksum for the corrupted table, which results in "matching checksums" when backup engine tries to verfiy the checksum, and causes a flaky test.
Fix the issue by adding `Flush()` before trying to corrupt a table file in *db*.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7082
Test Plan:
`buck test`
Without the fix, failed 5 of 100 tests.
Suspected whether the pseudo randomness causes the issue: doubling `keys_iteration` resulted in 2 of 100 tests failed; deterministically corrupting tables file also caused 2 of 100 tests to fail.
With the fix, passed 200 of 200 tests.
Reviewed By: pdillinger
Differential Revision: D22375421
Pulled By: gg814
fbshipit-source-id: 7304618e7520684b6087e42d0b58329c5ad18329