From 7ccef13ad51b5c6e194788bb00b620a16bfd9a56 Mon Sep 17 00:00:00 2001
From: riverwanderer <58135975+riverwanderer@users.noreply.github.com>
Date: Mon, 18 Sep 2023 07:23:20 +0100
Subject: [PATCH] Trap regex error.

---
 .../java/VASSAL/configure/ConfigureTree.java   | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/vassal-app/src/main/java/VASSAL/configure/ConfigureTree.java b/vassal-app/src/main/java/VASSAL/configure/ConfigureTree.java
index c2bd235aca..ae1cec1c34 100644
--- a/vassal-app/src/main/java/VASSAL/configure/ConfigureTree.java
+++ b/vassal-app/src/main/java/VASSAL/configure/ConfigureTree.java
@@ -2662,15 +2662,17 @@ else if (c instanceof PrototypeDefinition) {
      */
     private boolean checkString(String target, String searchString) {
       if (searchParameters.isMatchRegex()) {
-        // patch search string to avoid exception when Regex starts with * only
-        if (searchString.substring(0, 1).equals("*")) {
-          searchString = "." + searchString;
-        }
-        if (searchParameters.isMatchCase()) {
-          return target.matches(searchString);
+        try {
+          if (searchParameters.isMatchCase()) {
+            return target.matches(searchString);
+          }
+          else {
+            return target.toLowerCase().matches(searchString.toLowerCase());
+          }
         }
-        else {
-          return target.toLowerCase().matches(searchString.toLowerCase());
+        catch (java.util.regex.PatternSyntaxException e) {
+          logger.error("Search string is not a valid Regular Expression: " + e.getMessage()); //NON-NLS
+          return false;
         }
       }
       else {