git-submodule: Motivate --record with an example use case

Signed-off-by: W. Trevor King <wking@tremily.us>

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 9a99826d5c7bd1aadb86b41c993c48cb22f182c2..d4e993faff3a77959b6c1bd3484d628e51e9277e 100644 (file)
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -220,6 +220,14 @@ OPTIONS
        is not set either, `HEAD` will be recorded.  Because the branch name
        is optional, you must use the equal-sign form (`-r=<branch>`), not
        `-r <branch>`.
++
+The recorded setting is not actually used by git; however, some
+external tools and workflows may make use of it.  For example, if the
+upstream branches still exist and you have a recorded branch setting
+for each of your submodules, you can update all of the submodules to
+the current branch tips with:
++
+       git submodule foreach 'git checkout $submodule_branch && git pull'
 
 -f::
 --force::