X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/3bd9f270ec6af9b2e2897bf7d3cc3e91c8cf14dd..8dad1c49bab966ff0e1878c4508d0eeef68a9d62:/unix/gtkfont.c

diff --git a/unix/gtkfont.c b/unix/gtkfont.c
index 1aa1df85..123731a1 100644
--- a/unix/gtkfont.c
+++ b/unix/gtkfont.c
@@ -430,7 +430,7 @@ static int x11font_has_glyph(unifont *font, wchar_t glyph)
         char sbstring[2];
         int sblen = wc_to_mb(xfont->real_charset, 0, &glyph, 1,
                              sbstring, 2, "", NULL, NULL);
-        if (!sbstring[0])
+        if (sblen == 0 || !sbstring[0])
             return FALSE;              /* not even in the charset */
 
         return x11_font_has_glyph(xfont->fonts[0], 0,