From a8f10f24ece04ffee57610adf7b2e06d3a365b9f Mon Sep 17 00:00:00 2001
From: Bobby Holley <bobbyholley@gmail.com>
Date: Fri, 5 May 2017 13:48:53 -0700
Subject: [PATCH] Bug 1362549 - Assert against accessing the attributes of a
 snapshot that doesn't have attributes saved. r=emilio

MozReview-Commit-ID: 8BsnTF6uIGM
---
 layout/style/ServoElementSnapshot.cpp | 2 +-
 layout/style/ServoElementSnapshot.h   | 8 +++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/layout/style/ServoElementSnapshot.cpp b/layout/style/ServoElementSnapshot.cpp
index 29999ffe3749..1ef36308abd3 100644
--- a/layout/style/ServoElementSnapshot.cpp
+++ b/layout/style/ServoElementSnapshot.cpp
@@ -32,7 +32,7 @@ ServoElementSnapshot::AddAttrs(Element* aElement)
 {
   MOZ_ASSERT(aElement);
 
-  if (HasAny(Flags::Attributes)) {
+  if (HasAttrs()) {
     return;
   }
 
diff --git a/layout/style/ServoElementSnapshot.h b/layout/style/ServoElementSnapshot.h
index 7a064d9e110d..0b3b797b999d 100644
--- a/layout/style/ServoElementSnapshot.h
+++ b/layout/style/ServoElementSnapshot.h
@@ -70,9 +70,9 @@ public:
   explicit ServoElementSnapshot(const Element* aElement);
   ~ServoElementSnapshot();
 
-  bool HasAttrs() { return HasAny(Flags::Attributes); }
+  bool HasAttrs() const { return HasAny(Flags::Attributes); }
 
-  bool HasState() { return HasAny(Flags::State); }
+  bool HasState() const { return HasAny(Flags::State); }
 
   /**
    * Captures the given state (if not previously captured).
@@ -95,6 +95,7 @@ public:
    */
   BorrowedAttrInfo GetAttrInfoAt(uint32_t aIndex) const
   {
+    MOZ_ASSERT(HasAttrs());
     if (aIndex >= mAttrs.Length()) {
       return BorrowedAttrInfo(nullptr, nullptr);
     }
@@ -109,6 +110,7 @@ public:
   const nsAttrValue* GetParsedAttr(nsIAtom* aLocalName,
                                    int32_t aNamespaceID) const
   {
+    MOZ_ASSERT(HasAttrs());
     uint32_t i, len = mAttrs.Length();
     if (aNamespaceID == kNameSpaceID_None) {
       // This should be the common case so lets make an optimized loop
@@ -135,7 +137,7 @@ public:
     return mIsInChromeDocument;
   }
 
-  bool HasAny(Flags aFlags) { return bool(mContains & aFlags); }
+  bool HasAny(Flags aFlags) const { return bool(mContains & aFlags); }
 
 private:
   // TODO: Profile, a 1 or 2 element AutoTArray could be worth it, given we know