From 32b05936a96b753d44facc0f6f5ae074d12b1ef5 Mon Sep 17 00:00:00 2001
From: Matt Brubeck <mbrubeck@limpet.net>
Date: Tue, 8 Nov 2016 11:46:26 -0800
Subject: [PATCH] Bug 1292275 - Stylo: Fix crash after failed stylesheet load.
 r=heycam

Fixes a crash ServoStyleSet::AddDocStyleSheet caused by
ServoStyleSheet::RawSheet returning null.

MozReview-Commit-ID: BdDosompqTv
---
 ports/geckolib/glue.rs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/ports/geckolib/glue.rs b/ports/geckolib/glue.rs
index c3c9b856dd4..70131075f0c 100644
--- a/ports/geckolib/glue.rs
+++ b/ports/geckolib/glue.rs
@@ -164,6 +164,22 @@ pub extern "C" fn Servo_Node_ClearNodeData(node: RawGeckoNodeBorrowed) -> () {
     }
 }
 
+#[no_mangle]
+pub extern "C" fn Servo_StyleSheet_Empty(mode: SheetParsingMode) -> RawServoStyleSheetStrong {
+    let url = Url::parse("about:blank").unwrap();
+    let extra_data = ParserContextExtraData::default();
+    let origin = match mode {
+        SheetParsingMode::eAuthorSheetFeatures => Origin::Author,
+        SheetParsingMode::eUserSheetFeatures => Origin::User,
+        SheetParsingMode::eAgentSheetFeatures => Origin::UserAgent,
+    };
+    let sheet = Arc::new(Stylesheet::from_str("", url, origin, Box::new(StdoutErrorReporter),
+                                              extra_data));
+    unsafe {
+        transmute(sheet)
+    }
+}
+
 #[no_mangle]
 pub extern "C" fn Servo_StyleSheet_FromUTF8Bytes(data: *const nsACString,
                                                  mode: SheetParsingMode,