Teach 'diff' about 'diff' attribute.

diff --git a/git-checkout.sh b/git-checkout.sh
index 14835a4aa982af88d758ea014afacf7b2fb1bb1e..deb0a9a3c733ed889158d05b7cae4d174917553d 100755 (executable)
--- a/git-checkout.sh
+++ b/git-checkout.sh
@@ -12,6 +12,7 @@ new=
 new_name=
 force=
 branch=
+track=
 newbranch=
 newbranch_log=
 merge=
@@ -33,7 +34,10 @@ while [ "$#" != "0" ]; do
                        die "git checkout: we do not like '$newbranch' as a branch name."
                ;;
        "-l")
-               newbranch_log=1
+               newbranch_log=-l
+               ;;
+       "--track"|"--no-track")
+               track="$arg"
                ;;
        "-f")
                force=1
@@ -85,6 +89,11 @@ while [ "$#" != "0" ]; do
     esac
 done
 
+case "$newbranch,$track" in
+,--*)
+       die "git checkout: --track and --no-track require -b"
+esac
+
 case "$force$merge" in
 11)
        die "git checkout: -f and -m are incompatible"
@@ -154,7 +163,14 @@ cd_to_toplevel
 detached=
 detach_warn=
 
-if test -z "$branch$newbranch" && test "$new" != "$old"
+describe_detached_head () {
+       test -n "$quiet" || {
+               printf >&2 "$1 "
+               GIT_PAGER= git log >&2 -1 --pretty=oneline --abbrev-commit "$2"
+       }
+}
+
+if test -z "$branch$newbranch" && test "$new_name" != "$old_name"
 then
        detached="$new"
        if test -n "$oldbranch" && test -z "$quiet"
@@ -164,9 +180,9 @@ If you want to create a new branch from this checkout, you may do so
 (now or later) by using -b with the checkout command again. Example:
   git checkout -b <new_branch_name>"
        fi
-elif test -z "$oldbranch" && test -z "$quiet"
+elif test -z "$oldbranch" && test "$new" != "$old"
 then
-       echo >&2 "Previous HEAD position was $old"
+       describe_detached_head 'Previous HEAD position was' "$old"
 fi
 
 if [ "X$old" = X ]
@@ -196,7 +212,7 @@ else
        work=`git write-tree` &&
        git read-tree --reset -u $new || exit
 
-       eval GITHEAD_$new=${new_name:-${branch:-$new}} &&
+       eval GITHEAD_$new='${new_name:-${branch:-$new}}' &&
        eval GITHEAD_$work=local &&
        export GITHEAD_$new GITHEAD_$work &&
        git merge-recursive $old -- $new $work
@@ -235,18 +251,19 @@ fi
 #
 if [ "$?" -eq 0 ]; then
        if [ "$newbranch" ]; then
-               if [ "$newbranch_log" ]; then
-                       mkdir -p $(dirname "$GIT_DIR/logs/refs/heads/$newbranch")
-                       touch "$GIT_DIR/logs/refs/heads/$newbranch"
-               fi
-               git-update-ref -m "checkout: Created from $new_name" "refs/heads/$newbranch" $new || exit
+               git-branch $track $newbranch_log "$newbranch" "$new_name" || exit
                branch="$newbranch"
        fi
        if test -n "$branch"
        then
                GIT_DIR="$GIT_DIR" git-symbolic-ref -m "checkout: moving to $branch" HEAD "refs/heads/$branch"
-               if test -z "$quiet"
+               if test -n "$quiet"
+               then
+                       true    # nothing
+               elif test "refs/heads/$branch" = "$oldbranch"
                then
+                       echo >&2 "Already on branch \"$branch\""
+               else
                        echo >&2 "Switched to${newbranch:+ a new} branch \"$branch\""
                fi
        elif test -n "$detached"
@@ -265,6 +282,7 @@ if [ "$?" -eq 0 ]; then
                then
                        echo >&2 "$detach_warn"
                fi
+               describe_detached_head 'HEAD is now at' HEAD
        fi
        rm -f "$GIT_DIR/MERGE_HEAD"
 else