From 20b2e8f1e8dc27e84f1d3ca97a6efbc22b6afb24 Mon Sep 17 00:00:00 2001
From: Paulo Gustavo Veiga <pveiga@wisemapping.com>
Date: Sat, 26 Mar 2022 21:06:51 -0300
Subject: [PATCH] Improve mindmap format validation.

---
 .../src/main/java/com/wisemapping/model/MindmapUtils.java | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/wise-webapp/src/main/java/com/wisemapping/model/MindmapUtils.java b/wise-webapp/src/main/java/com/wisemapping/model/MindmapUtils.java
index c3d96579..5607ea22 100644
--- a/wise-webapp/src/main/java/com/wisemapping/model/MindmapUtils.java
+++ b/wise-webapp/src/main/java/com/wisemapping/model/MindmapUtils.java
@@ -36,10 +36,16 @@ abstract public class MindmapUtils {
             throw InvalidMindmapException.invalidFormat(xmlDoc);
         }
 
-        // Validate that the number of nodes is not bigger 500 nodes.
         int numberOfTopics = xmlDoc.split("<topic").length;
+        // Any valid map must contain at least a central topic ...
+        if (numberOfTopics == 0) {
+            throw InvalidMindmapException.invalidFormat(xmlDoc);
+        }
+
+        // Validate that the number of nodes is not bigger 5000 nodes.
         if (numberOfTopics > MAX_SUPPORTED_NODES) {
             throw InvalidMindmapException.tooBigMindnap(numberOfTopics);
         }
+
     }
 }