upload-pack: make sure deepening preserves shallow roots

diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt
index ba1fe4958227dce5ab146a39374cf02c127c0c65..a83d2b4778a016e8d8f6ead29d9122a7eff49fdb 100644 (file)
--- a/Documentation/fetch-options.txt
+++ b/Documentation/fetch-options.txt
@@ -14,8 +14,12 @@
        branch history. Tags for the deepened commits are not fetched.
 
 --unshallow::
-       Convert a shallow repository to a complete one, removing all
-       the limitations imposed by shallow repositories.
+       If the source repository is complete, convert a shallow
+       repository to a complete one, removing all the limitations
+       imposed by shallow repositories.
++
+If the source repository is shallow, fetch as much as possible so that
+the current repository has the same history as the source repository.
 
 ifndef::git-pull[]
 --dry-run::