From bceb2ee2c6383744beb5cd470dbbc28fe4aa491a Mon Sep 17 00:00:00 2001
From: Matt Giuca <mgiuca@chromium.org>
Date: Fri, 7 Jun 2024 08:45:32 +1000
Subject: [PATCH] Processing steps for id now removes the fragment (#1122)

---
 index.html | 49 ++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 42 insertions(+), 7 deletions(-)

diff --git a/index.html b/index.html
index 2d84905b..41141077 100644
--- a/index.html
+++ b/index.html
@@ -640,8 +640,7 @@ <h3>
           </li>
           <li>If |scope| is failure, return.
           </li>
-          <li>From |scope|, remove the [=url/query=] and [=url/fragment=]
-          components.
+          <li>Set |scope|'s [=URL/query=] and [=URL/fragment=] to null.
           </li>
           <li>If |manifest|["start_url"] is not [=URL/within scope=] of
           |scope|, return.
@@ -873,13 +872,26 @@ <h3>
           application, it SHOULD treat that manifest as a description of a
           distinct application, even if it is served from the same URL as that
           of another application. When the user agent sees a manifest where
-          |manifest|["id"] is [=url/equal=] with [=URL serializer/exclude
-          fragment|exclude fragment true=] to the [=identity=] of an
+          |manifest|["id"] is [=url/equal=] (with [=URL/equals/exclude
+          fragments=] OPTIONALLY set to true) to the [=identity=] of an
           already-installed application, it SHOULD be used as a signal that
           this manifest is a replacement for the already-installed
           application's manifest, and not a distinct application, even if it is
           served from a different URL than the one seen previously.
         </p>
+        <aside class="note" title="Excluding fragments is best practice">
+          Since the [=process the id member|processing algorithm=] removes the
+          [=URL/fragment=] from the <code>[=manifest/id=]</code> member, it is
+          not strictly necessary to [=URL/equals/exclude fragments=] when
+          checking for a matching application. However, since old versions of
+          this spec (and, possibly, old user agents) did not remove the
+          [=URL/fragment=] from the [=URL=] at parse time, and relied only on
+          [=URL/equals/exclude fragments|excluding fragments=] during
+          comparisons, historical app data could contain [=URL/fragments=] in
+          the <code>[=manifest/id=]</code>. Therefore, it is best practice for
+          user agents to [=URL/equals/exclude fragments=] even when comparing
+          two [=URLs=] that ought not to have fragments.
+        </aside>
         <p class="note">
           The [=identity=] can be used by a service that collects lists of web
           applications to uniquely identify applications.
@@ -910,6 +922,8 @@ <h3>
           <li>If |id| is not [=same origin=] as |manifest|["start_url"],
           return.
           </li>
+          <li>Set |id|'s [=URL/fragment=] to null.
+          </li>
           <li>Set |manifest|["id"] to |id|.
           </li>
         </ol>
@@ -949,7 +963,7 @@ <h3>
                 "https://example.com/my-app/#here"
               </td>
               <td>
-                "https://example.com/my-app/#here"
+                "https://example.com/my-app/"
               </td>
             </tr>
             <tr>
@@ -985,6 +999,28 @@ <h3>
                 "https://example.com/foo"
               </td>
             </tr>
+            <tr>
+              <td>
+                "foo?x=y"
+              </td>
+              <td>
+                "https://example.com/my-app/start"
+              </td>
+              <td>
+                "https://example.com/foo?x=y"
+              </td>
+            </tr>
+            <tr>
+              <td>
+                "foo#heading"
+              </td>
+              <td>
+                "https://example.com/my-app/start"
+              </td>
+              <td>
+                "https://example.com/foo"
+              </td>
+            </tr>
             <tr>
               <td>
                 "./foo"
@@ -1312,8 +1348,7 @@ <h3>
             </li>
             <li>If the [=document=]'s [=document|processed manifest=] is not
             null, and [=document=]'s [=document|processed manifest=]'s id is
-            not [=URL/equal=] with [=URL serializer/exclude fragment|exclude
-            fragment true=] to |manifest|["id"], return.
+            not [=URL/equal=] to |manifest|["id"], return.
             </li>
             <li>[=Process the `scope` member=] passing |json|, |manifest|, and
             |manifest URL|.