[css-text] Change the definition of pre-wrap

Based on a resolution from the 2015 New York face to face,
this makes sure that white spaces that fall at the end of the line
are preserved and allowed to wrap.

Author: frivoal

css-text/Overview.bs

@@ -648,9 +648,13 @@ Languages and Typesetting</h4>
           invisible, but retains its <a>soft wrap opportunity</a>, if any.)</li>
       </ol>
     </li>
-    <li><p>If 'white-space' is set to ''pre-wrap'', any sequence of
-      spaces is treated as a sequence of non-breaking spaces. However,
-      a <a>soft wrap opportunity</a> exists at the end of the sequence.</p></li>
+    <li><p>If 'white-space' is set to ''pre-wrap'',
+      any sequence of spaces is preserved.
+      This is achieved by treating it as a sequence of non-breaking spaces,
+      except that a <a>soft wrap opportunity</a> exists
+      between each of the spaces of this preserved sequence,
+      as well as at the beginning
+      and at the end of the sequence.</p></li>
     </ul>
 
     <p>Then, the entire block is rendered. Inlines are laid out, taking bidi
@@ -735,9 +739,6 @@ Languages and Typesetting</h4>
         from the block's starting content edge.
         The tab size is given by the 'tab-size' property.
       <li>A sequence of <a>collapsible</a> spaces at the end of a line is removed.
-      <li>If spaces or tabs at the end of a line are non-collapsible but
-         have 'white-space' set to ''pre-wrap'' the UA may visually
-         collapse their character advance widths.
     </ol>
 
     <p>White space that was not removed or collapsed during the white space

css-text/Overview.html

@@ -1271,9 +1271,13 @@ <h4 class="heading settled" data-level="4.1.1" id="white-space-phase-1"><span cl
 
 
      <li>
-      <p>If <a class="property" data-link-type="propdesc" href="#propdef-white-space">white-space</a> is set to <a class="css" data-link-type="maybe" href="#valdef-white-space-pre-wrap">pre-wrap</a>, any sequence of
-      spaces is treated as a sequence of non-breaking spaces. However,
-      a <a data-link-type="dfn" href="#soft-wrap-opportunity">soft wrap opportunity</a> exists at the end of the sequence.</p>
+      <p>If <a class="property" data-link-type="propdesc" href="#propdef-white-space">white-space</a> is set to <a class="css" data-link-type="maybe" href="#valdef-white-space-pre-wrap">pre-wrap</a>,
+      any sequence of spaces is preserved.
+      This is achieved by treating it as a sequence of non-breaking spaces,
+      except that a <a data-link-type="dfn" href="#soft-wrap-opportunity">soft wrap opportunity</a> exists
+      between each of the spaces of this preserved sequence,
+      as well as at the beginning
+      and at the end of the sequence.</p>
 
 
     </ul>
@@ -1402,10 +1406,6 @@ <h4 class="heading settled" data-level="4.1.3" id="white-space-phase-2"><span cl
         The tab size is given by the <a class="property" data-link-type="propdesc" href="#propdef-tab-size">tab-size</a> property.
 
      <li>A sequence of <a data-link-type="dfn" href="#collapsible-white-space">collapsible</a> spaces at the end of a line is removed.
-      
-     <li>If spaces or tabs at the end of a line are non-collapsible but
-         have <a class="property" data-link-type="propdesc" href="#propdef-white-space">white-space</a> set to <a class="css" data-link-type="maybe" href="#valdef-white-space-pre-wrap">pre-wrap</a> the UA may visually
-         collapse their character advance widths.
 
     </ol>