Currently, if you have the following images:
foo/bar 1 23b27d50fb49
foo/bar 2 f2b86ec3fcc4
And you issue the following command:
docker tag foo/bar:2 foo/bar latest
docker will tag the "wrong" image, because the image id for foo/bar:1 starts
with a "2". That is, you'll end up with the following:
foo/bar 1 23b27d50fb49
foo/bar 2 f2b86ec3fcc4
foo/bar latest 23b27d50fb49
This commit reverses the priority given to tags vs. image ids in the
construction `<user>/<repo>:<tagOrId>`, meaning that if a tag that is an exact
match for the specified `tagOrId`, it will be tagged in preference to an image
with an id that happens to start with the correct character sequence.
Upstream-commit: 44b3e8d51b655d68d0a253c48c027360ff8c3a97
Component: engine
54ca7a355c