bisect: sanity check on terms

This is currently only a defensive check since the only terms are
bad/good and new/old, which pass it, but this is a preparation step for
accepting user-supplied terms.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-bisect.sh b/git-bisect.sh
index ea63223ab3b5d4f8fb0a9af45db4278aef010fb7..761ca6cca0ff7a5c3ee71bde77da52a1f7234853 100755 (executable)
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -535,9 +535,42 @@ get_terms () {
 write_terms () {
        TERM_BAD=$1
        TERM_GOOD=$2
+       if test "$TERM_BAD" = "$TERM_GOOD"
+       then
+               die "$(gettext "please use two different terms")"
+       fi
+       check_term_format "$TERM_BAD" bad
+       check_term_format "$TERM_GOOD" good
        printf '%s\n%s\n' "$TERM_BAD" "$TERM_GOOD" >"$GIT_DIR/BISECT_TERMS"
 }
 
+check_term_format () {
+       term=$1
+       git check-ref-format refs/bisect/"$term" ||
+       die "$(eval_gettext "'\$term' is not a valid term")"
+       case "$term" in
+       help|start|terms|skip|next|reset|visualize|replay|log|run)
+               die "$(eval_gettext "can't use the builtin command '\$term' as a term")"
+               ;;
+       bad|new)
+               if test "$2" != bad
+               then
+                       # In theory, nothing prevents swapping
+                       # completely good and bad, but this situation
+                       # could be confusing and hasn't been tested
+                       # enough. Forbid it for now.
+                       die "$(eval_gettext "can't change the meaning of term '\$term'")"
+               fi
+               ;;
+       good|old)
+               if test "$2" != good
+               then
+                       die "$(eval_gettext "can't change the meaning of term '\$term'")"
+               fi
+               ;;
+       esac
+}
+
 check_and_set_terms () {
        cmd="$1"
        case "$cmd" in