fixed empty object bug reported by @Tare05

the exact same problem as 062c43f
but with objects instead of lists

src/burp/BurpExtender.java

@@ -219,15 +219,16 @@ private void escapeUrlEncodedBytes(byte[] input, StringBuilder output,
 
 	private static void escapeJson(Json node, StringBuilder output) {
 		if (node.isObject()) {
-			String prefix = "{";
+			output.append('{');
 			Map<String, Json> tm = new TreeMap(String.CASE_INSENSITIVE_ORDER);
 			tm.putAll(node.asJsonMap());
-			for (Map.Entry<String, Json> e : tm.entrySet()) {
-				output.append(prefix);
-				prefix = ", ";
-				escapeString(e.getKey(), output);
-				output.append(": ");
-				escapeJson(e.getValue(), output);
+			final Iterator<Map.Entry<String, Json>> iter = tm.entrySet().iterator();
+			if (iter.hasNext()) {
+				appendIteratedEntry(iter, output);
+				while (iter.hasNext()) {
+					output.append(", ");
+					appendIteratedEntry(iter, output);
+				}
 			}
 			output.append('}');
 		} else if (node.isArray()) {
@@ -252,6 +253,13 @@ private static void escapeJson(Json node, StringBuilder output) {
 		}
 	}
 
+	private static void appendIteratedEntry(Iterator<Map.Entry<String, Json>> iter, StringBuilder output) {
+		final Map.Entry<String, Json> e = iter.next();
+		escapeString(e.getKey(), output);
+		output.append(": ");
+		escapeJson(e.getValue(), output);
+	}
+
 	private static String byteSliceToString(byte[] input, int from, int till) {
 		try {
 			return new String(input, from, till - from, "ISO-8859-1");