sparse-checkout: document interactions with submodules

Using 'git submodule (init|deinit)' a user can select a subset of
submodules to populate. This behaves very similar to the sparse-checkout
feature, but those directories contain their own .git directory
including an object database and ref space. To have the sparse-checkout
file also determine if those files should exist would easily cause
problems. Therefore, keeping these features independent in this way
is the best way forward.

Also create a test that demonstrates this behavior to make sure
it doesn't change as the sparse-checkout feature evolves.

Reported-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/Documentation/git-sparse-checkout.txt b/Documentation/git-sparse-checkout.txt
index 67be5247b9..3b341cf0fc 100644
--- a/Documentation/git-sparse-checkout.txt
+++ b/Documentation/git-sparse-checkout.txt
@@ -164,6 +164,16 @@ case-insensitive check. This corrects for case mismatched filenames in the
 'git sparse-checkout set' command to reflect the expected cone in the working
 directory.
 
+
+SUBMODULES
+----------
+
+If your repository contains one or more submodules, then those submodules will
+appear based on which you initialized with the `git submodule` command. If
+your sparse-checkout patterns exclude an initialized submodule, then that
+submodule will still appear in your working directory.
+
+
 SEE ALSO
 --------