[PATCH] Update tags to record who made them

[git.git] / git-checkout-script

diff --git a/git-checkout-script b/git-checkout-script
index dc1cffd..7e70338 100755 (executable)
--- a/git-checkout-script
+++ b/git-checkout-script
@@ -1,27 +1,55 @@
 #!/bin/sh
-: ${GIT_DIR=.git}
-old=$(git-rev-parse HEAD)
-new=$(git-rev-parse --revs-only "$@")
-new=${new:-$old}
-args=($(git-rev-parse --no-revs "$@"))
+. git-sh-setup-script || die "Not a git archive"
 
-i=0
+old=$(git-rev-parse HEAD)
+new=
 force=
-update=
-while [ $i -lt ${#args} ]; do
-    case "${args[$i]}" in
+branch=
+newbranch=
+while [ "$#" != "0" ]; do
+    arg="$1"
+    shift
+    case "$arg" in
+       "-b")
+               newbranch="$1"
+               shift
+               [ -z "$newbranch" ] &&
+                       die "git checkout: -b needs a branch name"
+               [ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
+                       die "git checkout: branch $newbranch already exists"
+               ;;
        "-f")
-               force=1;;
-       "-u")
-               update=1;;
-       "")
+               force=1
                ;;
        *)
-               echo "unknown flag ${args[$i]}"
-               exit 1;;
+               rev=$(git-rev-parse --verify --revs-only "$arg^0") || exit
+               if [ -z "$rev" ]; then
+                       echo "unknown flag $arg"
+                       exit 1
+               fi
+               if [ "$new" ]; then
+                       echo "Multiple revisions?"
+                       exit 1
+               fi
+               new="$rev"
+               if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
+                       branch="$arg"
+               fi
+               ;;
     esac
     i=$(($i+1))
 done
+[ -z "$new" ] && new=$old
+
+#
+# If we don't have an old branch that we're switching to,
+# and we don't have a new branch name for the target we
+# are switching to, then we'd better just be checking out
+# what we already had
+#
+[ -z "$branch$newbranch" ] &&
+       [ "$new" != "$old" ] &&
+       die "git checkout: you need to specify a new branch name"
 
 if [ "$force" ]
 then
@@ -29,5 +57,19 @@ then
        git-checkout-cache -q -f -u -a
 else
     git-read-tree -m -u $old $new
-fi && [ "$update" ] && echo $new > "$GIT_DIR/HEAD"
+fi
 
+# 
+# Switch the HEAD pointer to the new branch if it we
+# checked out a branch head, and remove any potential
+# old MERGE_HEAD's (subsequent commits will clearly not
+# be based on them, since we re-set the index)
+#
+if [ "$?" -eq 0 ]; then
+       if [ "$newbranch" ]; then
+               echo $new > "$GIT_DIR/refs/heads/$newbranch"
+               branch="$newbranch"
+       fi
+       [ "$branch" ] && ln -sf "refs/heads/$branch" "$GIT_DIR/HEAD"
+       rm -f "$GIT_DIR/MERGE_HEAD"
+fi