{"action":"created","issue":{"url":"https://api.github.com/repos/docker/docker/issues/11149","labels_url":"https://api.github.com/repos/docker/docker/issues/11149/labels{/name}","comments_url":"https://api.github.com/repos/docker/docker/issues/11149/comments","events_url":"https://api.github.com/repos/docker/docker/issues/11149/events","html_url":"https://github.com/docker/docker/pull/11149","id":59743608,"number":11149,"title":"Add support for advanced ${} uses","user":{"login":"duglin","id":1944671,"avatar_url":"https://avatars.githubusercontent.com/u/1944671?v=3","gravatar_id":"","url":"https://api.github.com/users/duglin","html_url":"https://github.com/duglin","followers_url":"https://api.github.com/users/duglin/followers","following_url":"https://api.github.com/users/duglin/following{/other_user}","gists_url":"https://api.github.com/users/duglin/gists{/gist_id}","starred_url":"https://api.github.com/users/duglin/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/duglin/subscriptions","organizations_url":"https://api.github.com/users/duglin/orgs","repos_url":"https://api.github.com/users/duglin/repos","events_url":"https://api.github.com/users/duglin/events{/privacy}","received_events_url":"https://api.github.com/users/duglin/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/docker/docker/labels/status/1-needs-design-review","name":"status/1-needs-design-review","color":"fef2c0"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":13,"created_at":"2015-03-04T03:00:07Z","updated_at":"2015-03-31T16:11:21Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/docker/docker/pulls/11149","html_url":"https://github.com/docker/docker/pull/11149","diff_url":"https://github.com/docker/docker/pull/11149.diff","patch_url":"https://github.com/docker/docker/pull/11149.patch"},"body":"In particular ${xxx:+...} and ${xxx:-...}\r\n\r\n~~This depends on https://github.com/docker/docker/pull/10431~~\r\n\r\nCloses #8667 "},"comment":{"url":"https://api.github.com/repos/docker/docker/issues/comments/88148243","html_url":"https://github.com/docker/docker/pull/11149#issuecomment-88148243","issue_url":"https://api.github.com/repos/docker/docker/issues/11149","id":88148243,"user":{"login":"duglin","id":1944671,"avatar_url":"https://avatars.githubusercontent.com/u/1944671?v=3","gravatar_id":"","url":"https://api.github.com/users/duglin","html_url":"https://github.com/duglin","followers_url":"https://api.github.com/users/duglin/followers","following_url":"https://api.github.com/users/duglin/following{/other_user}","gists_url":"https://api.github.com/users/duglin/gists{/gist_id}","starred_url":"https://api.github.com/users/duglin/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/duglin/subscriptions","organizations_url":"https://api.github.com/users/duglin/orgs","repos_url":"https://api.github.com/users/duglin/repos","events_url":"https://api.github.com/users/duglin/events{/privacy}","received_events_url":"https://api.github.com/users/duglin/received_events","type":"User","site_admin":false},"created_at":"2015-03-31T16:11:21Z","updated_at":"2015-03-31T16:11:21Z","body":"@tiborvass yes `{$..:-...}` is the primary usecase but I added support for `${...:+...}` too since it was trivial to add - mainly for symmetry with `${...:-...}`. I don't think adding this should be much of a concern since `${}` has been supported for a while and we simply error-out if someone uses a modifier (like - or +) we don't understand. So all we're really doing is changing an error case to a valid case to allow more bash-like semantics. No invention here, just giving the user more stuff that they're used to seeing."}}