submodule update: consistently document the '--checkout' option

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 2e1c7a28d0fb00714748bf21de02c1f044a39b62..70e09cc5583deac5b79459127a21a6bfd3898dbc 100644 (file)
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -15,7 +15,7 @@ SYNOPSIS
 'git submodule' [--quiet] init [--] [<path>...]
 'git submodule' [--quiet] deinit [-f|--force] [--] <path>...
 'git submodule' [--quiet] update [--init] [--remote] [-N|--no-fetch]
-             [-f|--force] [--rebase|--merge|--checkout] [--reference <repository>]
+             [-f|--force] [--checkout|--rebase|--merge] [--reference <repository>]
              [--depth <depth>] [--recursive] [--] [<path>...]
 'git submodule' [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
              [commit] [--] [<path>...]
@@ -305,6 +305,15 @@ SHA-1.  If you don't want to fetch, you should use `submodule update
        This option is only valid for the update command.
        Don't fetch new objects from the remote site.
 
+--checkout::
+       This option is only valid for the update command.
+       Checkout the commit recorded in the superproject on a detached HEAD
+       in the submodule. This is the default behavior, the main use of
+       this option is to override `submodule.$name.update` when set to
+       `merge`, `rebase` or `none`.
+       If the key `submodule.$name.update` is either not explicitly set or
+       set to `checkout`, this option is implicit.
+
 --merge::
        This option is only valid for the update command.
        Merge the commit recorded in the superproject into the current branch