Bug 1640160 - Serialize mRequestContextId with BrowsingContext's IPCInitializer to ensure that we don't try to create a request context with an id of 0. r=nika

This was a bit of pain to track down, because some code was allowing an ID of 0, and creating a request context to match, but other code was treating 0 as invalid.

Differential Revision: https://phabricator.services.mozilla.com/D76652

docshell/base/BrowsingContext.cpp

@@ -2383,6 +2383,7 @@ void IPDLParamTraits<dom::BrowsingContext::IPCInitializer>::Write(
   WriteIPDLParam(aMessage, aActor, aInit.mUseRemoteTabs);
   WriteIPDLParam(aMessage, aActor, aInit.mUseRemoteSubframes);
   WriteIPDLParam(aMessage, aActor, aInit.mOriginAttributes);
+  WriteIPDLParam(aMessage, aActor, aInit.mRequestContextId);
   WriteIPDLParam(aMessage, aActor, aInit.mFields);
 }
 
@@ -2397,6 +2398,7 @@ bool IPDLParamTraits<dom::BrowsingContext::IPCInitializer>::Read(
       !ReadIPDLParam(aMessage, aIterator, aActor,
                      &aInit->mUseRemoteSubframes) ||
       !ReadIPDLParam(aMessage, aIterator, aActor, &aInit->mOriginAttributes) ||
+      !ReadIPDLParam(aMessage, aIterator, aActor, &aInit->mRequestContextId) ||
       !ReadIPDLParam(aMessage, aIterator, aActor, &aInit->mFields)) {
     return false;
   }

netwerk/base/RequestContextService.cpp

@@ -505,6 +505,10 @@ RequestContextService::GetRequestContext(const uint64_t rcID,
     return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
   }
 
+  if (!rcID) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
   if (!mTable.Get(rcID, rc)) {
     nsCOMPtr<nsIRequestContext> newSC = new RequestContext(rcID);
     mTable.Put(rcID, newSC);

uriloader/base/nsDocLoader.cpp

@@ -143,6 +143,9 @@ nsresult nsDocLoader::Init() {
 nsresult nsDocLoader::InitWithBrowsingContext(
     BrowsingContext* aBrowsingContext) {
   RefPtr<net::nsLoadGroup> loadGroup = new net::nsLoadGroup();
+  if (!aBrowsingContext->GetRequestContextId()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
   nsresult rv = loadGroup->InitWithRequestContextId(
       aBrowsingContext->GetRequestContextId());
   if (NS_FAILED(rv)) return rv;