1272432 - [FlyWeb] Always set attributes in nsDNSServicediscovery when resolving service.

Status: RESOLVED FIXED

(Core :: Networking, defect)

Description

[Kannan Vijayan [:djvj]]

Attachment: always-set-nsdnsserviceinfo-attributes-on-osx.patch

nsDNSServiceDiscovery doesn't set nsDNSServiceInfo::attributes if there are no TXT records in the metadata.

It should set the attribute to the empty hash if that's the case, instead of leaving it nullptr.  Leaving it null breaks semantics: the nsDNSServiceInfo is supposed to be fully resolved and have all fields defined by the time it gets set to the onServiceResolved callback.

Comment 1

[Justin D'Arcangelo [:justindarc]]

Comment on attachment 8751834 [details] [diff] [review]
always-set-nsdnsserviceinfo-attributes-on-osx.patch

Review of attachment 8751834 [details] [diff] [review]:
-----------------------------------------------------------------

LGTM

Comment 2

[Kannan Vijayan [:djvj]]

https://hg.mozilla.org/projects/larch/rev/2362715386da

Comment 3

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

Comment on attachment 8751834 [details] [diff] [review]
always-set-nsdnsserviceinfo-attributes-on-osx.patch

Review of attachment 8751834 [details] [diff] [review]:
-----------------------------------------------------------------

::: netwerk/dns/mdns/libmdns/MDNSResponderOperator.cpp
@@ +631,5 @@
>    // Resolve TXT record
>    int count = TXTRecordGetCount(aTxtLen, aTxtRecord);
>    LOG_I("resolve: txt count = %d, len = %d", count, aTxtLen);
> +  nsCOMPtr<nsIWritablePropertyBag2> attributes = new nsHashPropertyBag();
> +  if (NS_WARN_IF(!attributes)) { return; }

This nullcheck is a no-op these days. Our default |operator new| will exit() if the allocation fails, so we'll never get to the if-statement with a null |attributes|.