From d8bd29292e32f8398d90ce942d23c363f9adef43 Mon Sep 17 00:00:00 2001
From: Boris Chiou <boris.chiou@gmail.com>
Date: Mon, 12 Nov 2018 19:21:32 +0000
Subject: [PATCH] style: Parse any order of number and angle for Rotate.

Rotate accepts rotate axis and angle in any order
(i.e. <number>{3} <angle> or <angle> <number>{3}), so we rewrite the
parser.

Differential Revision: https://phabricator.services.mozilla.com/D11417
---
 .../style/values/specified/transform.rs       | 31 +++++++++++++------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/components/style/values/specified/transform.rs b/components/style/values/specified/transform.rs
index c1ffe202a79..38ac07edf63 100644
--- a/components/style/values/specified/transform.rs
+++ b/components/style/values/specified/transform.rs
@@ -357,17 +357,28 @@ impl Parse for Rotate {
             return Ok(generic::Rotate::None);
         }
 
-        if let Ok(rx) = input.try(|i| Number::parse(context, i)) {
-            // 'rotate: <number>{3} <angle>'
-            let ry = Number::parse(context, input)?;
-            let rz = Number::parse(context, input)?;
-            let angle = specified::Angle::parse(context, input)?;
-            return Ok(generic::Rotate::Rotate3D(rx, ry, rz, angle));
-        }
+        // Parse <angle> or [ x | y | z | <number>{3} ] && <angle>.
+        // TODO: Bug 1504327: Parse [x|y|z] keywords.
+        //
+        // The rotate axis and angle could be in any order, so we parse angle twice to cover
+        // two cases. i.e. `<number>{3} <angle>` or `<angle> <number>{3}`
+        let angle = input.try(|i| specified::Angle::parse(context, i)).ok();
+        let axis = input.try(|i| -> Result<_, ParseError> {
+            Ok((
+                Number::parse(context, i)?,
+                Number::parse(context, i)?,
+                Number::parse(context, i)?,
+            ))
+        }).ok();
+        let angle = match angle {
+            Some(a) => a,
+            None => specified::Angle::parse(context, input)?,
+        };
 
-        // 'rotate: <angle>'
-        let angle = specified::Angle::parse(context, input)?;
-        Ok(generic::Rotate::Rotate(angle))
+        Ok(match axis {
+            Some((x, y, z)) => generic::Rotate::Rotate3D(x, y, z, angle),
+            None => generic::Rotate::Rotate(angle),
+        })
     }
 }