submodule: Add --force option for git submodule update

By default git submodule update runs a simple checkout on submodules that
are not up-to-date. If the submodules contains modified or untracked
files, the command may exit sanely with an error:

  $ git submodule update
  error: Your local changes to the following files would be overwritten by
  checkout:
	  file
  Please, commit your changes or stash them before you can switch branches.
  Aborting
  Unable to checkout '1b69c6e55606b48d3284a3a9efe4b58bfb7e8c9e' in
  submodule path 'test1'

In order to reset a whole git submodule tree, a user has to run first 'git
submodule foreach --recursive git checkout -f' and then run 'git submodule
update'.

This patch adds a --force option for the update command (only used for
submodules without --rebase or --merge options). It passes the --force
option to git checkout which will throw away the local changes.

Signed-off-by: Nicolas Morey-Chaisemartin <nmorey@kalray.eu>
Acked-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 1ed331c599d4b492b0dec112332bb83db5506d74..9f84da7ad61260f0b151d60a51bee4151a96151f 100644 (file)
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -185,8 +185,10 @@ OPTIONS
 
 -f::
 --force::
-       This option is only valid for the add command.
-       Allow adding an otherwise ignored submodule path.
+       This option is only valid for add and update commands.
+       When running add, allow adding an otherwise ignored submodule path.
+       When running update, throw away local changes in submodules when
+       switching to a different commit.
 
 --cached::
        This option is only valid for status and summary commands.  These

diff --git a/git-submodule.sh b/git-submodule.sh
index 3a13397e057edf88d2c810490ec3d7d755be2009..f7327090bbe80b3bc553d0fe8774a02c76c48749 100755 (executable)
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -8,7 +8,7 @@ dashless=$(basename "$0" | sed -e 's/-/ /')
 USAGE="[--quiet] add [-b branch] [-f|--force] [--reference <repository>] [--] <repository> [<path>]
    or: $dashless [--quiet] status [--cached] [--recursive] [--] [<path>...]
    or: $dashless [--quiet] init [--] [<path>...]
-   or: $dashless [--quiet] update [--init] [-N|--no-fetch] [--rebase] [--reference <repository>] [--merge] [--recursive] [--] [<path>...]
+   or: $dashless [--quiet] update [--init] [-N|--no-fetch] [-f|--force] [--rebase] [--reference <repository>] [--merge] [--recursive] [--] [<path>...]
    or: $dashless [--quiet] summary [--cached|--files] [--summary-limit <n>] [commit] [--] [<path>...]
    or: $dashless [--quiet] foreach [--recursive] <command>
    or: $dashless [--quiet] sync [--] [<path>...]"
@@ -385,6 +385,9 @@ cmd_update()
                -N|--no-fetch)
                        nofetch=1
                        ;;
+               -f|--force)
+                       force=$1
+                       ;;
                -r|--rebase)
                        update="rebase"
                        ;;
@@ -458,10 +461,11 @@ cmd_update()
 
                if test "$subsha1" != "$sha1"
                then
-                       force=
-                       if test -z "$subsha1"
+                       subforce=$force
+                       # If we don't already have a -f flag and the submodule has never been checked out
+                       if test -z "$subsha1" -a -z "$force"
                        then
-                               force="-f"
+                               subforce="-f"
                        fi
 
                        if test -z "$nofetch"
@@ -490,7 +494,7 @@ cmd_update()
                                msg="merged in"
                                ;;
                        *)
-                               command="git checkout $force -q"
+                               command="git checkout $subforce -q"
                                action="checkout"
                                msg="checked out"
                                ;;

diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
index fa9d23aa31302f53cc1c39473492cf545ca5ae87..5d24d9ff74595174a4549bb165fcc8a0800d8120 100755 (executable)
--- a/t/t7406-submodule-update.sh
+++ b/t/t7406-submodule-update.sh
@@ -74,6 +74,29 @@ test_expect_success 'submodule update detaching the HEAD ' '
        )
 '
 
+test_expect_success 'submodule update should fail due to local changes' '
+       (cd super/submodule &&
+        git reset --hard HEAD~1 &&
+        echo "local change" > file
+       ) &&
+       (cd super &&
+        (cd submodule &&
+         compare_head
+        ) &&
+        test_must_fail git submodule update submodule
+       )
+'
+test_expect_success 'submodule update should throw away changes with --force ' '
+       (cd super &&
+        (cd submodule &&
+         compare_head
+        ) &&
+        git submodule update --force submodule &&
+        cd submodule &&
+        ! compare_head
+       )
+'
+
 test_expect_success 'submodule update --rebase staying on master' '
        (cd super/submodule &&
          git checkout master