Allow method="POST"

Web Share Target can generate GET or POST requests.

Author: ericwilligers

index.html

@@ -247,12 +247,12 @@ <h3>
           <code>undefined</code>.
           </li>
           <li>If <var>share target</var>["<a data-link-for=
-          "ShareTarget">method</a>"] is not an <a data-cite=
+          "ShareTarget">method</a>"] is neither an <a data-cite=
           "!INFRA#ascii-case-insensitive">ASCII case-insensitive</a> match for
-          the string <code>"GET"</code>, <a data-cite=
-          "!appmanifest#dfn-issue-a-developer-warning">issue a developer
-          warning</a> that the method is not supported, and return
-          <code>undefined</code>.
+          the strings <code>"GET"</code> nor <code>"POST"</code>,
+            <a data-cite="!appmanifest#dfn-issue-a-developer-warning">issue a
+            developer warning</a> that the method is not supported, and return
+            <code>undefined</code>.
           </li>
           <li>Let <var>action</var> be the result of <a data-cite=
           "!URL#concept-url-parser">parsing</a> the <a data-cite=
@@ -454,7 +454,7 @@ <h3>
           run the following steps:
         </p>
         <ol>
-          <li>Let <var>action</var> be
+          <li>Let <var>url</var> be a copy of
           <var>manifest</var>["<a>share_target</a>"]["<a data-link-for=
           "ShareTarget">action</a>"].
           </li>
@@ -483,16 +483,62 @@ <h3>
               </li>
             </ul>
           </li>
-          <li>Let <var>query</var> be the result of running the <a data-cite=
-          "!URL#concept-urlencoded-serializer"><code>application/x-www-form-urlencoded</code>
-          serializer</a> with entry list and no encoding override.
+          <li>Let <var>header list</var> be a new empty <a data-cite=
+          "!FETCH/#concept-header-list">header list</a>.
+          </li>
+          <li>Let <var>method</var> be
+          <var>manifest</var>["<a>share_target</a>"]["<a data-link-for=
+          "ShareTarget">method</a>"].
+          </li>
+          <li>If <var>method</var> is <code>"GET"</code>:
+            <ol>
+              <li>Let <var>query</var> be the result of running the
+              <a data-cite=
+              "!URL#concept-urlencoded-serializer"><code>application/x-www-form-urlencoded</code>
+              serializer</a> with <var>entry list</var> and no encoding
+              override.
+              </li>
+              <li>Set <var>url</var>'s <a data-cite=
+              "!URL#concept-url-query">query</a> component to <var>query</var>.
+              </li>
+              <li>Let <var>body</var> be null.
+              </li>
+            </ol>
+          </li>
+          <li>Otherwise, if <var>method</var> is <code>"POST"</code>:
+            <ol>
+              <li>Let <var>body</var> be the result of running the
+                <a data-cite="!HTML#multipart/form-data-encoding-algorithm"><code>
+                multipart/form-data</code> encoding algorithm</a> with
+                <var>entry list</var> and <a data-cite="!UTF-8">UTF-8</a>
+                encoding.
+              </li>
+              <li>Let <var>MIME type</var> be the concatenation of the string
+              <code>"multipart/form-data;"</code>, a U+0020 SPACE character,
+              the string <code>"boundary="</code>, and the <a data-cite=
+              "!HTML#multipart/form-data-boundary-string"><code>multipart/form-data</code>
+              boundary string</a> generated by the <a data-cite=
+              "!HTML#multipart/form-data-encoding-algorithm"><code>multipart/form-data</code>
+              encoding algorithm</a>.
+              </li>
+              <li>
+                <a data-cite="!FETCH/#concept-header-list-append">Append</a>
+                <code>Content-Type/</code><var>MIME type</var> to <var>header
+                list</var>.
+              </li>
+            </ol>
           </li>
-          <li>Set <var>action</var>'s <a data-cite=
-          "!URL#concept-url-query">query</a> component to <var>query</var>.
+          <li>Let <var>browsing context</var> be the result of creating a
+          <a data-cite="!HTML#creating-a-new-browsing-context">new</a>
+          <a data-cite="!HTML#top-level-browsing-context">top-level browsing
+          context</a>.
           </li>
-          <li>Run the <a data-cite="!HTML#window-open-steps">window open
-          steps</a> on <var>action</var>, with empty <var>target</var> and
-          empty <var>features</var>.
+          <li>
+            <a data-cite="!HTML#navigate">Navigate</a> <var>browsing
+            context</var> to a new <a data-cite=
+            "!FETCH/#concept-request">request</a> whose method is
+            <var>method</var>, url is <var>url</var>, header list is
+            <var>header list</var>, and body is <var>body</var>.
           </li>
         </ol>
         <p class="note">