From 422639fb60234dad3c139c3d2395d5d51f28f70f Mon Sep 17 00:00:00 2001
From: Olaf Buddenhagen <antrik@users.sf.net>
Date: Sun, 13 Dec 2015 02:00:19 +0100
Subject: [PATCH] layout/text.rs: Add assertion for empty fontgroup

---
 components/layout/text.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/components/layout/text.rs b/components/layout/text.rs
index d28cea4c0e2..c8ef3ad2b5d 100644
--- a/components/layout/text.rs
+++ b/components/layout/text.rs
@@ -186,6 +186,8 @@ impl TextRunScanner {
                     // Search for the first font in this font group that contains a glyph for this
                     // character.
                     let mut font_index = 0;
+                    // The following code panics one way or another if this condition isn't met.
+                    assert!(fontgroup.fonts.len() > 0);
                     while font_index < fontgroup.fonts.len() - 1 {
                         if fontgroup.fonts.get(font_index).unwrap().borrow()
                                           .glyph_index(character)