commit 70a16104e386c26b69c4db1fe575ce5016c1396c
author Zac Livingston <zacl@codeaurora.org> Tue Nov 20 15:07:34 2018 -0700
committer Nasser Grainawi <nasser@codeaurora.org> Tue Oct 22 12:35:39 2019 -0600
tree 4dfe4b69ff9373f2071ba05101957cf5bc4b56eb
parent 547b1108063e5411b0c3f97eb94b4f77bc4d88c5

Enable aliases for change query operators

Site administrators can alias change query operators from a plugin
using the 'operator-alias' section and 'change' subsection in
gerrit.config:

[operator-alias "change"]
  oldage = age
  number = change

Aliases are already supported for SSH commands [1] and URLs [2].

This feature is particularly useful to alias operator names which may be
long and clunky because they include a plugin name in them to a shorter
name without the plugin name. Admins should take care to pick short
names that are unique and unlikely to be used by future operators.

Aliases are resolved dynamically at invocation time to any currently
loaded versions of plugins. If the alias points to an operator provided
by a plugin which is not currently loaded, or the plugin does not define
the operator, then "unsupported operator" is returned to the user.

Aliases will override existing operators. In the case of multiple aliases
with the same name, the last one defined will be used.

When the target of an alias doesn't exist, the operator with the name
of the alias will be used (if present). This enables an admin to config
the system to override a core operator with an operator provided by a
plugin when present and otherwise fall back to the operator provided by
core.

The above three features can make aliases useful for cases of moving
functionality from Gerrit core to plugins and vice versa.

[1] https://gerrit-review.googlesource.com/Documentation/config-gerrit.html#ssh-alias
[2] https://gerrit-review.googlesource.com/Documentation/config-gerrit.html#urlAlias

Change-Id: I3c60b0b9bc84467fece4b7d30dc735509e28071d