Auto merge of #12008 - servo:keyframes, r=Manishearth

Reorder code in KeyframesAnimation::from_keyframes() to avoid a panic.

Fixes #11999.
Fixes #12006.

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1 files changed, 5 insertions, 1 deletions

diff --git a/components/style/keyframes.rs b/components/style/keyframes.rs
index cbfa35b78c4..7d219758848 100644
--- a/components/style/keyframes.rs
+++ b/components/style/keyframes.rs
@@ -154,8 +154,12 @@ fn get_animated_properties(keyframe: &Keyframe) -> Vec<TransitionProperty> {
 
 impl KeyframesAnimation {
     pub fn from_keyframes(keyframes: &[Keyframe]) -> Option<Self> {
+        if keyframes.is_empty() {
+            return None;
+        }
+
         let animated_properties = get_animated_properties(&keyframes[0]);
-        if keyframes.is_empty() || animated_properties.is_empty() {
+        if animated_properties.is_empty() {
             return None;
         }