added GraphViz support

[sbp.git] / src / edu / berkeley / sbp / util / StringUtil.java

diff --git a/src/edu/berkeley/sbp/util/StringUtil.java b/src/edu/berkeley/sbp/util/StringUtil.java
index 41e67e9..8c046ee 100644 (file)
--- a/src/edu/berkeley/sbp/util/StringUtil.java
+++ b/src/edu/berkeley/sbp/util/StringUtil.java
@@ -55,6 +55,7 @@ public class StringUtil {
     */
     public static String escapify(String s) { return escapify(s, "\\\n\r"); }
     public static String escapify(String s, String illegal) {
+        if (s==null) return null;
         StringBuffer sb = new StringBuffer();
         for(int i=0; i<s.length(); i++) {
             char c = s.charAt(i);