--cap-lints does not downgrade lint levels for subsequent lint control flags

[matthiaskrgr]

I order to silence all lints but one when using clippy, I can do something like cargo clippy -- -Aclippy::all -Wclippy::redundant_clone however this does not work when a crate denys clippy lints!

Thus I tried to override the lint level to warn with cargo clippy -- --cap-lints warn -Aclippy::all -Wclippy::redundant_clone but the -Aclippy.. -Wclippy.. flags do not affect messages that were forced from deny to warn with --cap-lints and the ex-deny-level lint warnings are still printed (as warning instead of error); filtering out undesired deny-messages completely did not work.
This looks like a bug.

rustc 1.47.0-nightly (6c8927b0c 2020-07-26)
binary: rustc
commit-hash: 6c8927b0cf80ceee19386026cf9d7fd4fd9d486f
commit-date: 2020-07-26
host: x86_64-unknown-linux-gnu
release: 1.47.0-nightly
LLVM version: 10.0