updated for version 7.3.541
Problem:    When joining lines comment leaders need to be removed manually.
Solution:   Add the 'j' flag to 'formatoptions'. (Lech Lorens)
diff --git a/src/normal.c b/src/normal.c
index 3c66a37..6688a9d 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -1968,7 +1968,7 @@
 		beep_flush();
 	    else
 	    {
-		(void)do_join(oap->line_count, oap->op_type == OP_JOIN, TRUE);
+		(void)do_join(oap->line_count, oap->op_type == OP_JOIN, TRUE, TRUE);
 		auto_format(FALSE, TRUE);
 	    }
 	    break;
@@ -4426,7 +4426,7 @@
 	    break;
 	}
 #ifdef FEAT_COMMENTS
-	if (get_leader_len(ml_get_curline(), NULL, FALSE) > 0)
+	if (get_leader_len(ml_get_curline(), NULL, FALSE, TRUE) > 0)
 	{
 	    /* Ignore this line, continue at start of next line. */
 	    ++curwin->w_cursor.lnum;
@@ -9324,7 +9324,7 @@
 	{
 	    prep_redo(cap->oap->regname, cap->count0,
 			 NUL, cap->cmdchar, NUL, NUL, cap->nchar);
-	    (void)do_join(cap->count0, cap->nchar == NUL, TRUE);
+	    (void)do_join(cap->count0, cap->nchar == NUL, TRUE, TRUE);
 	}
     }
 }