Document that imports and global owners are always read from the current revisions

The GetCodeOwnersForPathInBranch REST endpoint allows to specify a
revision from which the code owner config files in this branch should be
read. Clarify in the documentation that imports from other branches or
repositories as well as global code owners from refs/meta/config are
still read from the current revisions.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I968977a0d1214f59804234367f0a31f202a3df84
diff --git a/java/com/google/gerrit/plugins/codeowners/restapi/GetCodeOwnersForPathInBranch.java b/java/com/google/gerrit/plugins/codeowners/restapi/GetCodeOwnersForPathInBranch.java
index 6e3d054..c2c22df 100644
--- a/java/com/google/gerrit/plugins/codeowners/restapi/GetCodeOwnersForPathInBranch.java
+++ b/java/com/google/gerrit/plugins/codeowners/restapi/GetCodeOwnersForPathInBranch.java
@@ -61,7 +61,12 @@
   private final GitRepositoryManager repoManager;
   private String revision;
 
-  @Option(name = "-revision", usage = "revision from which the code owner configs should be read")
+  @Option(
+      name = "-revision",
+      usage =
+          "revision from which the code owner configs in the branch should be read (imports from"
+              + " other branches or repositories as well as global code owners from refs/meta/config"
+              + " are still read from the current revisions)")
   public void setRevision(String revision) {
     this.revision = revision;
   }
diff --git a/resources/Documentation/rest-api.md b/resources/Documentation/rest-api.md
index 2a0cb32..9afd554 100644
--- a/resources/Documentation/rest-api.md
+++ b/resources/Documentation/rest-api.md
@@ -287,7 +287,7 @@
 | `o`         | optional | [Account option](../../../Documentation/rest-api-accounts.html#query-options) that controls which fields in the returned accounts should be populated. Can be specified multiple times. If not given, only the `_account_id` field for the account ID is populated.
 | `O`         | optional | [Account option](../../../Documentation/rest-api-accounts.html#query-options) in hex. For the explanation see `o` parameter.
 | `limit`\|`n` | optional | Limit defining how many code owners should be returned at most. By default 10.
-| `revision` | optional | Revision from which the code owner configs should be read as commit SHA1. Can be used to read historic code owners. If not specified the code owner configs are read from the HEAD revision of the branch. Not supported for getting code owners for a path in a change.
+| `revision` | optional | Revision from which the code owner configs should be read as commit SHA1. Can be used to read historic code owners from this branch, but imports from other branches or repositories as well as global code owners from `refs/meta/config` are still read from the current revisions. If not specified the code owner configs are read from the HEAD revision of the branch. Not supported for getting code owners for a path in a change.
 
 As a response a list of [CodeOwnerInfo](#code-owner-info) entities is returned.
 The returned code owners are sorted by an internal score that expresses how good