3a09d2b95a
`docker rename foo ''` would result in: ``` usage: docker rename OLD_NAME NEW_NAME ``` which is the old engine's way of return errors - yes that's in the daemon code. So I fixed that error msg to just be normal. While doing that I noticed that using an empty string for the source container name failed but didn't print any error message at all. This is because we would generate a URL like: ../containers//rename/.. which would cause a 301 redirect to ../containers/rename/.. however the CLI code doesn't actually deal with 301's - it just ignores them and returns back to the CLI code/caller. Rather than changing the CLI to deal with 3xx error codes, which would probably be a good thing to do in a follow-on PR, for this immediate issue I just added a cli-side check for empty strings for both old and new names. This way we catch it even before we hit the daemon. API callers will get a 404, assuming they follow the 301, for the case of the src being empty, and the new error msg when the destination is empty - so we should be good now. Add tests for both cases too. Signed-off-by: Doug Davis <dug@us.ibm.com> Upstream-commit: 848792c42e61070adc4107a39d6a044e2ed615f7 Component: engine