From 0e8f2c83cf84767df7bfbcc02b1d475008d6939e Mon Sep 17 00:00:00 2001
From: David Grieve <dagrieve@microsoft.com>
Date: Wed, 14 Jun 2023 09:45:16 -0400
Subject: [PATCH] fix potential substring(0,0)

---
 .../java/com/microsoft/gctoolkit/parser/UnifiedG1GCParser.java | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/parser/src/main/java/com/microsoft/gctoolkit/parser/UnifiedG1GCParser.java b/parser/src/main/java/com/microsoft/gctoolkit/parser/UnifiedG1GCParser.java
index cc1c834..55b0139 100644
--- a/parser/src/main/java/com/microsoft/gctoolkit/parser/UnifiedG1GCParser.java
+++ b/parser/src/main/java/com/microsoft/gctoolkit/parser/UnifiedG1GCParser.java
@@ -199,7 +199,8 @@ public class UnifiedG1GCParser extends UnifiedGCLogParser implements UnifiedG1GC
                 .findAny()
                 .ifPresentOrElse(
                         tuple -> {
-                            setForwardReference(gcid, line.substring(0, end));
+                            // Typically, "end" will be greater than zero, but not always.
+                            setForwardReference(gcid, end > 0 ? line.substring(0, end) : line);
                             applyRule(tuple.getKey(), tuple.getValue(), line);
                         },
                         () -> log(line)