From 8c8bc16905ad140c1552ee6f0d455ef9591bbe43 Mon Sep 17 00:00:00 2001
From: ManoloFLTK <41016272+ManoloFLTK@users.noreply.github.com>
Date: Fri, 30 Jan 2026 09:04:24 +0100
Subject: Fix in Fl_Text_Buffer::next_char() necessary for empty buffer.

---
 src/Fl_Text_Buffer.cxx | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Fl_Text_Buffer.cxx b/src/Fl_Text_Buffer.cxx
index ef300f19b..b0be2d94c 100644
--- a/src/Fl_Text_Buffer.cxx
+++ b/src/Fl_Text_Buffer.cxx
@@ -2145,7 +2145,8 @@ int Fl_Text_Buffer::next_char(int pos) const
         break;
       }
     }
-    l = fl_utf8_next_composed_char(t, t + l) - t; // length of possibly composed character starting at pos
+    // length of possibly composed character starting at pos
+    l = (l > 0 ? fl_utf8_next_composed_char(t, t + l) - t : 0);
   } else if (l == -1) {
     l = 1;
   }
-- 
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