# Fetch one or more remote refs and merge it/them into the current HEAD.
. git-sh-setup-script || die "Not a git archive"
-git-fetch-script "$@" || exit 1
+
+orig_head=$(cat "$GIT_DIR/HEAD") || die "Pulling into a black hole?"
+git-fetch-script --update-head-ok "$@" || exit 1
+
+curr_head=$(cat "$GIT_DIR/HEAD")
+if test "$curr_head" != "$orig_head"
+then
+ # The fetch involved updating the current branch.
+
+ # The working tree and the index file is still based on the
+ # $orig_head commit, but we are merging into $curr_head.
+ # First update the working tree to match $curr_head.
+
+ echo >&2 "Warning: fetch updated the current branch head."
+ echo >&2 "Warning: fast forwarding your working tree."
+ git-read-tree -u -m "$orig_head" "$curr_head" ||
+ die "You need to first update your working tree."
+fi
+
merge_head=$(sed -e 's/ .*//' "$GIT_DIR"/FETCH_HEAD | tr '\012' ' ')
merge_name=$(sed -e 's/^[0-9a-f]* //' "$GIT_DIR"/FETCH_HEAD |
tr '\012' ' ')