Add review for file-lock v1.1.20

YdnEoYtqvbBGv0hhENLDUYmc3tNfm5V5NIG5hCovHyM/reviews/2021-05-package-0Oh57g.proof.crev

@@ -0,0 +1,42 @@
+----- BEGIN CREV PROOF -----
+kind: package review
+version: -1
+date: "2021-05-21T14:00:32.881465652+02:00"
+from:
+  id-type: crev
+  id: YdnEoYtqvbBGv0hhENLDUYmc3tNfm5V5NIG5hCovHyM
+  url: "https://git.jcg.re/jcgruenhage/crev-proofs.git"
+package:
+  source: "https://crates.io"
+  name: file-lock
+  version: 1.1.20
+  digest: Av61358dytJkb_iBCTZzy-0J868RHCPLC1wgQ6o_VXk
+review:
+  thoroughness: high
+  understanding: high
+  rating: neutral
+flags:
+  unmaintained: true
+comment: |-
+  As the README claims, this locks files using the fcntl libc method, and it
+  provides locks for both read and write access. I've read the man pages for
+  that thoroughly and compared it to the implementation of this crate, and at
+  least the C part of it is nearly perfect. I would have named some things
+  differently, but aside of that, this part is good as it stands. It always
+  locks the whole file, uses the proper flags and in general looks good. As for
+  the rust part.. well, that's where the problems begin. The Drop impl does
+  unlock the file, but ignores the result of the unlocking (it calls .is_ok() on
+  the Result and ignores the return value, which is an antipattern also present
+  in all of the test cases). When aquiring an exclusive lock, it disables read
+  access to the file, causing bad fd errors when trying to read anyway. Last but
+  not least, this crate hasn't been updated for the 2018 edition, has tons of
+  warning and is using the deprecated and unmaintained gcc crate. These problems
+  are easily fixable, and where I'm using the crate, I'm using my fork which has
+  all these problems fixed, but considering that the other 3 MRs of the last
+  year haven't been fixed either, I have my doubts about this still being
+  maintained. If upstream continues to not respond, I'll fork this and update my
+  review with an alternative accordingly.
+----- SIGN CREV PROOF -----
+OsHzghhizKAFsZbIfwU1WjgLl5waAl17bAkB7JRF7q7Z72YKs6PMuVq400SS25Jc4lO1rgwUSmCVGfKBofe9AQ
+----- END CREV PROOF -----
+