Fixed extra -- lines (noted by Christophe Boyanique).
diff --git a/grep.c b/grep.c
index 061462e..07646e0 100644
--- a/grep.c
+++ b/grep.c
@@ -60,7 +60,8 @@
 {
 #ifdef BB_FEATURE_GREP_CONTEXT
 	/* possibly print the little '--' seperator */
-	if (last_line_printed && last_line_printed < linenum - 1) {
+	if ((lines_before || lines_after) && last_line_printed &&
+			last_line_printed < linenum - 1) {
 		puts("--");
 	}
 	last_line_printed = linenum;