1 files changed, 8 insertions, 2 deletions
diff --git a/vcl/unx/gtk3/gtk3gtkframe.cxx b/vcl/unx/gtk3/gtk3gtkframe.cxx
index 113fcb425963..8a18974d2635 100644
--- a/vcl/unx/gtk3/gtk3gtkframe.cxx
+++ b/vcl/unx/gtk3/gtk3gtkframe.cxx
@@ -3977,8 +3977,14 @@ void GtkSalFrame::IMHandler::signalIMPreeditChanged( GtkIMContext*, gpointer im_
         ExtTextInputAttr sal_attr = ExtTextInputAttr::NONE;
 
         pango_attr_iterator_range (iter, &start, &end);
-        if (end == G_MAXINT)
-            end = pText ? g_utf8_strlen(pText, -1) : 0;
+        if (start == G_MAXINT || end == G_MAXINT)
+        {
+            auto len = pText ? g_utf8_strlen(pText, -1) : 0;
+            if (end == G_MAXINT)
+                end = len;
+            if (start == G_MAXINT)
+                start = len;
+        }
         if (end == start)
             continue;