From f9a8fe0afef5b4a6bac6071b812a4faac0f963b7 Mon Sep 17 00:00:00 2001
From: Michael Howell <michael@notriddle.com>
Date: Fri, 1 Jul 2016 21:02:28 -0700
Subject: [PATCH] Do not crash on partial calc interpolation

Fixes #12151

Fixes regression introduced by #11924
---
 .../style/properties/helpers/animated_properties.mako.rs      | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/components/style/properties/helpers/animated_properties.mako.rs b/components/style/properties/helpers/animated_properties.mako.rs
index 552f5b303c3..ad34f59dc89 100644
--- a/components/style/properties/helpers/animated_properties.mako.rs
+++ b/components/style/properties/helpers/animated_properties.mako.rs
@@ -329,8 +329,8 @@ impl Interpolate for CalcLengthOrPercentage {
     #[inline]
     fn interpolate(&self, other: &Self, time: f64) -> Result<Self, ()> {
         Ok(CalcLengthOrPercentage {
-            length: try!(self.length.interpolate(&other.length, time)),
-            percentage: try!(self.percentage.interpolate(&other.percentage, time)),
+            length: self.length.interpolate(&other.length, time).ok().and_then(|x|x),
+            percentage: self.percentage.interpolate(&other.percentage, time).ok().and_then(|x|x),
         })
     }
 }