Fixing ready promise definition (#1487)

Test PR: web-platform-tests/wpt#20655

Author: jakearchibald

docs/index.bs

@@ -690,7 +690,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
 
     A {{ServiceWorkerContainer}} has an associated <dfn for="ServiceWorkerContainer">service worker client</dfn>, which is a [=/service worker client=] whose [=environment settings object/global object=] is associated with the {{Navigator}} object or the {{WorkerNavigator}} object that the {{ServiceWorkerContainer}} is retrieved from.
 
-    A {{ServiceWorkerContainer}} object has an associated <dfn for="ServiceWorkerContainer">ready promise</dfn> (a [=promise=]). It is initially set to [=a new promise=].
+    A {{ServiceWorkerContainer}} object has an associated <dfn for="ServiceWorkerContainer">ready promise</dfn> (a [=promise=] or null). It is initially null.
 
     A {{ServiceWorkerContainer}} object has a <a>task source</a> called the <dfn export id="dfn-client-message-queue" for="ServiceWorkerContainer">client message queue</dfn>, initially empty. A [=ServiceWorkerContainer/client message queue=] can be enabled or disabled, and is initially disabled. When a {{ServiceWorkerContainer}} object's [=ServiceWorkerContainer/client message queue=] is enabled, the <a>event loop</a> *must* use it as one of its <a>task sources</a>. When the {{ServiceWorkerContainer}} object's <a>relevant global object</a> is a {{Window}} object, all <a>tasks</a> <a lt="queue a task">queued</a> on its [=ServiceWorkerContainer/client message queue=] *must* be associated with its <a>relevant settings object</a>'s <a>responsible document</a>.
 
@@ -711,6 +711,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
 
       <dfn attribute for="ServiceWorkerContainer"><code>ready</code></dfn> attribute *must* run these steps:
 
+        1. If the [=context object=]'s [=ServiceWorkerContainer/ready promise=] is null, then set the [=context object=]'s [=ServiceWorkerContainer/ready promise=] to [=a new promise=].
         1. Let |readyPromise| be the [=context object=]'s [=ServiceWorkerContainer/ready promise=].
         1. If |readyPromise| is pending, run the following substeps [=in parallel=]:
             1. Let |registration| be the result of running [=Match Service Worker Registration=] with the [=context object=]'s [=ServiceWorkerContainer/service worker client=]'s [=creation URL=].
@@ -2782,6 +2783,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
       1. Let |matchedClients| be a [=list=] of [=/service worker clients=] whose <a>creation URL</a> <a lt="Match Service Worker Registration">matches</a> |registration|'s [=service worker registration/scope url=].
       1. [=list/For each=] |client| of |matchedClients|, [=queue a task=] on |client|'s [=responsible event loop=], using the [=DOM manipulation task source=], to run the following substeps:
           1. Let |readyPromise| be |client|'s [=environment settings object/global object=]'s {{ServiceWorkerContainer}} object's [=ServiceWorkerContainer/ready promise=].
+          1. If |readyPromise| is null, then [=continue=].
           1. <span id="activate-resolve-ready-step">If |readyPromise| is pending, resolve |readyPromise| with the the result of [=getting the service worker registration object=] that represents |registration| in |readyPromise|'s [=relevant settings object=]</span>.
       1. [=list/For each=] |client| of |matchedClients|:
           1. If |client| is a <a>window client</a>, unassociate |client|'s <a>responsible document</a> from its <a>application cache</a>, if it has one.

docs/v1/index.bs

@@ -654,7 +654,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
 
     A {{ServiceWorkerContainer}} has an associated <dfn for="ServiceWorkerContainer">service worker client</dfn>, which is a [=/service worker client=] whose [=environment settings object/global object=] is associated with the {{Navigator}} object or the {{WorkerNavigator}} object that the {{ServiceWorkerContainer}} is retrieved from.
 
-    A {{ServiceWorkerContainer}} object has an associated <dfn for="ServiceWorkerContainer">ready promise</dfn> (a [=promise=]). It is initially set to [=a new promise=].
+    A {{ServiceWorkerContainer}} object has an associated <dfn for="ServiceWorkerContainer">ready promise</dfn> (a [=promise=] or null). It is initially null.
 
     A {{ServiceWorkerContainer}} object has a <a>task source</a> called the <dfn export id="dfn-client-message-queue" for="ServiceWorkerContainer">client message queue</dfn>, initially empty. A [=ServiceWorkerContainer/client message queue=] can be enabled or disabled, and is initially disabled. When a {{ServiceWorkerContainer}} object's [=ServiceWorkerContainer/client message queue=] is enabled, the <a>event loop</a> *must* use it as one of its <a>task sources</a>. When the {{ServiceWorkerContainer}} object's <a>relevant global object</a> is a {{Window}} object, all <a>tasks</a> <a lt="queue a task">queued</a> on its [=ServiceWorkerContainer/client message queue=] *must* be associated with its <a>relevant settings object</a>'s <a>responsible document</a>.
 
@@ -675,6 +675,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
 
       <dfn attribute for="ServiceWorkerContainer"><code>ready</code></dfn> attribute *must* run these steps:
 
+        1. If the [=context object=]'s [=ServiceWorkerContainer/ready promise=] is null, then set the [=context object=]'s [=ServiceWorkerContainer/ready promise=] to [=a new promise=].
         1. Let |readyPromise| be the [=context object=]'s [=ServiceWorkerContainer/ready promise=].
         1. If |readyPromise| is pending, run the following substeps [=in parallel=]:
             1. Let |registration| be the result of running [=Match Service Worker Registration=] with the [=context object=]'s [=ServiceWorkerContainer/service worker client=]'s [=creation URL=].
@@ -2593,6 +2594,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
       1. Let |matchedClients| be a [=list=] of [=/service worker clients=] whose <a>creation URL</a> <a lt="Match Service Worker Registration">matches</a> |registration|'s [=service worker registration/scope url=].
       1. [=list/For each=] |client| of |matchedClients|, [=queue a task=] on |client|'s [=responsible event loop=], using the [=DOM manipulation task source=], to run the following substeps:
           1. Let |readyPromise| be |client|'s [=environment settings object/global object=]'s {{ServiceWorkerContainer}} object's [=ServiceWorkerContainer/ready promise=].
+          1. If |readyPromise| is null, then [=continue=].
           1. <span id="activate-resolve-ready-step">If |readyPromise| is pending, resolve |readyPromise| with the the result of [=getting the service worker registration object=] that represents |registration| in |readyPromise|'s [=relevant settings object=]</span>.
       1. [=list/For each=] |client| of |matchedClients|:
           1. If |client| is a <a>window client</a>, unassociate |client|'s <a>responsible document</a> from its <a>application cache</a>, if it has one.