From b3c5f899047bdafb598d8d7d23c290d77ea9db71 Mon Sep 17 00:00:00 2001
From: Matt Woodrow <mwoodrow@mozilla.com>
Date: Fri, 24 Apr 2020 07:01:02 +0000
Subject: [PATCH] Bug 1602318 - Disable parent-initiated loads when using
 devtools. r=nika,ochameau

Differential Revision: https://phabricator.services.mozilla.com/D71136
---
 docshell/base/BrowsingContext.cpp          | 7 +++++++
 docshell/base/BrowsingContext.h            | 3 +++
 docshell/base/CanonicalBrowsingContext.cpp | 9 +++++++++
 docshell/base/nsDocShell.cpp               | 1 +
 4 files changed, 20 insertions(+)

diff --git a/docshell/base/BrowsingContext.cpp b/docshell/base/BrowsingContext.cpp
index c61c06d8dbc8..d76037c8b72c 100644
--- a/docshell/base/BrowsingContext.cpp
+++ b/docshell/base/BrowsingContext.cpp
@@ -201,6 +201,7 @@ already_AddRefed<BrowsingContext> BrowsingContext::CreateDetached(
       nsILoadInfo::EMBEDDER_POLICY_NULL);
   context->mFields.SetWithoutSyncing<IDX_OpenerPolicy>(
       nsILoadInfo::OPENER_POLICY_UNSAFE_NONE);
+  context->mFields.SetWithoutSyncing<IDX_WatchedByDevtools>(false);
 
   if (aOpener && aOpener->SameOriginWithTop()) {
     // We inherit the opener policy if there is a creator and if the creator's
@@ -1895,6 +1896,12 @@ bool BrowsingContext::CanSet(FieldIndex<IDX_AllowPlugins>,
   return CheckOnlyOwningProcessCanSet(aSource);
 }
 
+bool BrowsingContext::CanSet(FieldIndex<IDX_WatchedByDevtools>,
+                             const bool& aWatchedByDevtools,
+                             ContentParent* aSource) {
+  return CheckOnlyOwningProcessCanSet(aSource);
+}
+
 bool BrowsingContext::CanSet(FieldIndex<IDX_UserAgentOverride>,
                              const nsString& aUserAgent,
                              ContentParent* aSource) {
diff --git a/docshell/base/BrowsingContext.h b/docshell/base/BrowsingContext.h
index 1639d919bd87..170516a243c0 100644
--- a/docshell/base/BrowsingContext.h
+++ b/docshell/base/BrowsingContext.h
@@ -123,6 +123,7 @@ class WindowProxyHolder;
   FIELD(MessageManagerGroup, nsString)                                       \
   FIELD(MaxTouchPointsOverride, uint8_t)                                     \
   FIELD(FullZoom, float)                                                     \
+  FIELD(WatchedByDevtools, bool)                                             \
   FIELD(TextZoom, float)
 
 // BrowsingContext, in this context, is the cross process replicated
@@ -701,6 +702,8 @@ class BrowsingContext : public nsILoadContext, public nsWrapperCache {
               ContentParent* aSource);
   bool CanSet(FieldIndex<IDX_AllowPlugins>, const bool& aAllowPlugins,
               ContentParent* aSource);
+  bool CanSet(FieldIndex<IDX_WatchedByDevtools>, const bool& aWatchedByDevtools,
+              ContentParent* aSource);
 
   template <size_t I, typename T>
   bool CanSet(FieldIndex<I>, const T&, ContentParent*) {
diff --git a/docshell/base/CanonicalBrowsingContext.cpp b/docshell/base/CanonicalBrowsingContext.cpp
index 413ab3e9c906..f28981507cd3 100644
--- a/docshell/base/CanonicalBrowsingContext.cpp
+++ b/docshell/base/CanonicalBrowsingContext.cpp
@@ -536,6 +536,15 @@ bool CanonicalBrowsingContext::AttemptLoadURIInParent(
     return false;
   }
 
+  // We currently don't support initiating loads in the parent when they are
+  // watched by devtools. This is because devtools tracks loads using content
+  // process notifications, which happens after the load is initiated in this
+  // case. Devtools clears all prior requests when it detects a new navigation,
+  // so it drops the main document load that happened here.
+  if (GetWatchedByDevtools()) {
+    return false;
+  }
+
   // DocumentChannel currently only supports connecting channels into the
   // content process, so we can only support schemes that will always be loaded
   // there for now. Restrict to just http(s) for simplicity.
diff --git a/docshell/base/nsDocShell.cpp b/docshell/base/nsDocShell.cpp
index 37b087b78ddc..66e1a777ac15 100644
--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -12845,5 +12845,6 @@ nsDocShell::GetWatchedByDevtools(bool* aWatched) {
 NS_IMETHODIMP
 nsDocShell::SetWatchedByDevtools(bool aWatched) {
   mWatchedByDevtools = aWatched;
+  mBrowsingContext->SetWatchedByDevtools(aWatched);
   return NS_OK;
 }