From bc3a654486930578867d477e5bdfe600f773dae9 Mon Sep 17 00:00:00 2001
From: kennytm <kennytm@gmail.com>
Date: Tue, 11 Jul 2017 22:40:02 +0800
Subject: [PATCH] Improve Graphviz output.

---
 cov/src/graph.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/cov/src/graph.rs b/cov/src/graph.rs
index 6d15d76..62a15c3 100644
--- a/cov/src/graph.rs
+++ b/cov/src/graph.rs
@@ -935,6 +935,9 @@ impl Graph {
                     use std::fmt::Write;
                     write!(s, "{}{}", if i == 0 { '#' } else { ',' }, line).expect(":(");
                 }
+                if s.is_empty() {
+                    s.push('?');
+                }
                 s
             };
             writeln!(
@@ -943,7 +946,7 @@ impl Graph {
                  <table cellspacing=\"0\">\
                  <tr>\
                  <td rowspan=\"2\"><font color=\"{}\">{}</font></td>\
-                 <td><font point-size=\"9\">block {}</font></td>\
+                 <td><font point-size=\"9\">@{}</font></td>\
                  </tr>\
                  <tr>\
                  <td><font point-size=\"9\">{}</font></td>\