[] (0) Fix the navigation and history traversal algorithms so that th…

…e back button doesn't lock up the browser if the Document was evicted

git-svn-id: http://svn.whatwg.org/webapps@756 340c8d12-0b0e-0410-8428-c7bf67bfef74

index

@@ -22,7 +22,7 @@
 
    <h1 id=web-applications>Web Applications 1.0</h1>
 
-   <h2 class="no-num no-toc" id=working>Working Draft &mdash; 18 April 2007</h2>
+   <h2 class="no-num no-toc" id=working>Working Draft &mdash; 19 April 2007</h2>
 
    <p>You can take part in this work. <a
     href="http://www.whatwg.org/mailing-list">Join the working group's
@@ -22904,7 +22904,7 @@ XXX selection ranges -->
    <a href="#browsing0">browsing context</a> to the URI given in <var
    title="">url</var>. If the <var title="">replace</var> is true, then <a
    href="#replacement" title="replacement enabled">replacement must be
-   enabled</a>.
+   enabled</a>; otherwise, it must not be enabled.
 
   <h4 id=accessing><span class=secno>4.2.3. </span>Accessing other browsing
    contexts</h4>
@@ -23050,6 +23050,14 @@ XXX selection ranges -->
    act as follows:
 
   <ol>
+   <li>If there is no longer a <code>Document</code> object for the entry in
+    question, the user agent must <a href="#navigate">navigate</a> the
+    browsing context to the location for that entry to preform an <a
+    href="#entry">entry update</a> of that entry, and abort these steps. The
+    "<a href="#navigate">navigate</a>" algorithm reinvokes this "traverse"
+    algorithm to complete the traversal, at which point there <em>is</em> a
+    <code>Document</code> object and so this step gets skipped.
+
    <li>
     <p>If appropriate, update the <a href="#current0">current entry</a> in
      the <a href="#browsing0">browsing context</a>'s <code>Document</code>
@@ -23083,11 +23091,7 @@ XXX selection ranges -->
 
      <li>The user agent must make the specified entry's <code>Document</code>
       object the <a href="#active">active document</a> of the <a
-      href="#browsing0">browsing context</a>. If there is no
-      <code>Document</code> object for the entry in question, the user agent
-      must <a href="#navigate">navigate</a> the browsing context to the
-      location for that entry, with <a href="#replacement">replacement
-      enabled</a>.
+      href="#browsing0">browsing context</a>.
 
      <li>The user agent must move any properties that have been added to the
       <a href="#active">active document</a>'s <code>Document<code>'s <a
@@ -24716,20 +24720,19 @@ at the first element with the given ID must be treated as if it was cloned and r
    occur atomically.
 
   <dl>
-   <dt>If the navigation was initiated with <dfn id=replacement>replacement
-    enabled</dfn>
+   <dt>If the navigation was initiated for <dfn id=entry>entry update</dfn>
+    of an entry
 
    <dd>
     <ol>
      <li>
-      <p>Remove any entries preceding or following the <a
-       href="#current0">current entry</a> in the <a href="#session">session
-       history</a> that share the same <code>Document</code>.
+      <p>Replace the entry being updated with a new entry representing the
+       new resource and its <code>Document</code> object and related state.
+       The user agent may propagate state from the old entry to the new entry
+       (e.g. scroll position).
 
      <li>
-      <p>Replace the <a href="#current0">current entry</a> in the <a
-       href="#session">session history</a> with a new entry representing the
-       new resource and its <code>Document</code> object and related state.
+      <p><a href="#traverse">Traverse the history</a> to the new entry.
     </ol>
 
    <dt>Otherwise
@@ -24743,8 +24746,7 @@ at the first element with the given ID must be treated as if it was cloned and r
        href="#history1">History</a></code> object.</p>
 
       <p class=note>This <a href="#history-notes">doesn't necessarily have to
-       affect</a><!--XXX
-     change to auto-xref?--> the user agent's user
+       affect</a><!--XXX change to auto-xref?--> the user agent's user
        interface.</p>
 
      <li>
@@ -24754,12 +24756,14 @@ at the first element with the given ID must be treated as if it was cloned and r
 
      <li>
       <p><a href="#traverse">Traverse the history</a> to the new entry.
+
+     <li>
+      <p>If the navigation was initiated with <dfn id=replacement>replacement
+       enabled</dfn>, remove the entry immediately before the new <a
+       href="#current0">current entry</a> in the session history.
     </ol>
   </dl>
 
-  <p class=note>Navigation is initiated with replacement disabled unless it
-   is stated otherwise.
-
   <h4 id=read-html><span class=secno>4.5.1. </span><dfn id=page-load
    title=navigate-html>Page load processing model for HTML files</dfn></h4>
 

source

@@ -20528,7 +20528,7 @@ XXX selection ranges -->
   <span>browsing context</span> to the URI given in <var
   title="">url</var>. If the <var title="">replace</var> is true, then
   <span title="replacement enabled">replacement must be
-  enabled</span>.</p>
+  enabled</span>; otherwise, it must not be enabled.</p>
 
 
 
@@ -20679,6 +20679,15 @@ XXX selection ranges -->
 
   <ol>
 
+   <li>If there is no longer a <code>Document</code> object for the
+   entry in question, the user agent must <span>navigate</span> the
+   browsing context to the location for that entry to preform an
+   <span>entry update</span> of that entry, and abort these steps. The
+   "<span>navigate</span>" algorithm reinvokes this "traverse"
+   algorithm to complete the traversal, at which point there
+   <em>is</em> a <code>Document</code> object and so this step gets
+   skipped.</p></li>
+
    <li><p>If appropriate, update the <span>current entry</span> in the
    <span>browsing context</span>'s <code>Document</code> object's
    <code>History</code> object to reflect any state that the user
@@ -20710,11 +20719,7 @@ XXX selection ranges -->
 
      <li>The user agent must make the specified entry's
      <code>Document</code> object the <span>active document</span> of
-     the <span>browsing context</span>. If there is no
-     <code>Document</code> object for the entry in question, the user
-     agent must <span>navigate</span> the browsing context to the
-     location for that entry, with <span>replacement
-     enabled</span>.</p></li>
+     the <span>browsing context</span>.</p></li>
 
      <li>The user agent must move any properties that have been added
      to the <span>active document</span>'s <code>Document<code>'s
@@ -22256,53 +22261,55 @@ at the first element with the given ID must be treated as if it was cloned and r
 
   <dl>
 
-   <dt>If the navigation was initiated with <dfn>replacement
-   enabled</dfn></dt>
+   <dt>If the navigation was initiated for <dfn>entry update</dfn> of
+   an entry</dt>
 
    <dd>
 
     <ol>
 
-     <li><p>Remove any entries preceding or following the
-     <span>current entry</span> in the <span>session history</span>
-     that share the same <code>Document</code>.</p></li>
+     <li><p>Replace the entry being updated with a new entry
+     representing the new resource and its <code>Document</code>
+     object and related state. The user agent may propagate state from
+     the old entry to the new entry (e.g. scroll position).</p></li>
 
-     <li><p>Replace the <span>current entry</span> in the
-     <span>session history</span> with a new entry representing the
-     new resource and its <code>Document</code> object and related
-     state.</p></li>
+     <li><p><span>Traverse the history</span> to the new
+     entry.</p></li>
 
     </ol>
 
    </dd>
 
+
    <dt>Otherwise</dt>
 
    <dd>
 
     <ol>
 
-     <li><p>Remove all the entries after the <span>current entry</span>
-     in the <span>browsing context</span>'s <code>Document</code>
-     object's <code>History</code> object.</p> <p class="note">This <a
-     href="#history-notes">doesn't necessarily have to affect</a><!--XXX
-     change to auto-xref?--> the user agent's user interface.</p> </li>
+     <li><p>Remove all the entries after the <span>current
+     entry</span> in the <span>browsing context</span>'s
+     <code>Document</code> object's <code>History</code> object.</p>
+     <p class="note">This <a href="#history-notes">doesn't necessarily
+     have to affect</a><!--XXX change to auto-xref?--> the user
+     agent's user interface.</p> </li>
 
      <li><p>Append a new entry at the end of the <code>History</code>
-     object representing the new resource and its <code>Document</code>
-     object and related state.</p></li>
+     object representing the new resource and its
+     <code>Document</code> object and related state.</p></li>
 
      <li><p><span>Traverse the history</span> to the new entry.</p></li>
 
+     <li><p>If the navigation was initiated with <dfn>replacement
+     enabled</dfn>, remove the entry immediately before the new
+     <span>current entry</span> in the session history.</p></li>
+
     </ol>
 
    </dd>
 
   </dl>
 
-  <p class="note">Navigation is initiated with replacement disabled
-  unless it is stated otherwise.</p>
-
 
   <h4 id="read-html"><dfn title="navigate-html">Page load processing model for HTML files</dfn></h4>