Skip bad files entries and make accept required (#78)

If the name is an empty string, discard that files entry instead
of rejecting the entire share target.

If an accept entry is invalid, discard that accept entry instead
of rejecting either the files entry or the entire share target.

If accept is an empty array (either initially or because it only
contained invalid entries), discard the files entry.

Note an an empty accept array previously had the opposite
meaning, i.e. that the files entry accepted all files.

resolves #77

Author: ewilligers

level-2/index.html

@@ -283,7 +283,7 @@ <h2>
       <pre class="idl">
 dictionary ShareTargetFiles {
   required USVString name;
-  (USVString or sequence&lt;USVString&gt;) accept = [];
+  required (USVString or sequence&lt;USVString&gt;) accept;
 };
 
 dictionary ShareTargetParams {
@@ -386,7 +386,7 @@ <h3>
           dictionary, <var>bucket</var>, set <var>share
           target</var>["<a data-link-for=
           "ShareTarget">params</a>"]["<a data-link-for=
-          "ShareTargetParams">files</a>"] to [<var>bucket</var>].
+          "ShareTargetParams">files</a>"] to «<var>bucket</var>».
           </li>
           <li>If <var>share target</var>["<a data-link-for=
           "ShareTarget">params</a>"]["<a data-link-for=
@@ -411,19 +411,25 @@ <h3>
               <li>If <var>bucket</var>["<a data-link-for=
               "ShareTargetFiles">name</a>"] is an empty string, <a data-cite=
               "!appmanifest#dfn-issue-a-developer-warning">issue a developer
-              warning</a> and return <code>undefined</code>.
+              warning</a>, remove <var>bucket</var> from <var>share
+              target</var>["<a data-link-for=
+              "ShareTarget">params</a>"]["<a data-link-for=
+              "ShareTargetParams">files</a>"] and <a data-cite=
+              "!INFRA#iteration-continue">continue</a>.
               </li>
               <li>If <var>bucket</var>["<a data-link-for=
               "ShareTargetFiles">accept</a>"] is a <a data-cite=
               "!WEBIDL#idl-USVString">USVString</a>, <var>accept</var>, set
               <var>bucket</var>["<a data-link-for=
-              "ShareTargetFiles">accept</a>"] to [<var>accept</var>].
+              "ShareTargetFiles">accept</a>"] to «<var>accept</var>».
               </li>
-              <li>If <var>bucket</var>["<a data-link-for=
-              "ShareTargetFiles">accept</a>"] contains a string that does not
-              match any of the following, <a data-cite=
+              <li>For each string in <var>bucket</var>["<a data-link-for=
+              "ShareTargetFiles">accept</a>"] that does not match any of the
+              following, <a data-cite=
               "!appmanifest#dfn-issue-a-developer-warning">issue a developer
-              warning</a> and return <code>undefined</code>.
+              warning</a> and remove the string from
+              <var>bucket</var>["<a data-link-for=
+              "ShareTargetFiles">accept</a>"].
                 <ul>
                   <li>a string whose first character is a U+002E FULL STOP
                   character (.)
@@ -442,6 +448,14 @@ <h3>
                   </li>
                 </ul>
               </li>
+              <li>If <var>bucket</var>["<a data-link-for=
+              "ShareTargetFiles">accept</a>"] is empty, <a data-cite=
+              "!appmanifest#dfn-issue-a-developer-warning">issue a developer
+              warning</a> and remove <var>bucket</var> from <var>share
+              target</var>["<a data-link-for=
+              "ShareTarget">params</a>"]["<a data-link-for=
+              "ShareTargetParams">files</a>"].
+              </li>
             </ol>
           </li>
           <li>Let <var>action</var> be the result of <a data-cite=
@@ -550,8 +564,7 @@ <h3>
         <p>
           The <dfn>accept</dfn> member specifies a sequence of accepted MIME
           type(s) or file extension(s), the latter expressed as strings
-          starting with U+002E FULL STOP (.). An empty sequence indicates that
-          all files are accepted.
+          starting with U+002E FULL STOP (.).
         </p>
       </section>
     </section>
@@ -875,9 +888,6 @@ <h3>
           is as follows:-
         </p>
         <ol>
-          <li>If <var>bucket</var>["<a data-link-for=
-          "ShareTargetFiles">accept</a>"] is empty, return <code>true</code>.
-          </li>
           <li>For each <var>criterion</var> in
           <var>bucket</var>["<a data-link-for="ShareTargetFiles">accept</a>"]:
             <ol>