[css-break] Specify that cloned margins are truncated on block-level boxes.

Author: fantasai

css-break/Overview.bs

@@ -964,9 +964,11 @@ Adjoining Margins at Breaks</h3>
 
   <p>
     When an unforced break occurs between block-level boxes,
-    any margins adjoining the break truncate to the <i>remaining fragmentainer extent</i>.
+    any margins adjoining the break truncate to the <i>remaining fragmentainer extent</i> before the break,
+    and are truncated to zero after the break.
     When a forced break occurs there, adjoining margins before the break are truncated,
     but margins after the break are preserved.
+    <a href="#valdef-box-decoration-break-clone">Cloned margins</a> are always truncated to zero on block-level margins.
   </p>
 
 <h3 id="box-splitting">
@@ -1063,7 +1065,8 @@ Fragmented Borders and Backgrounds: the 'box-decoration-break' property</h3>
       The background is drawn independently in each fragment of the element.
       A no-repeat background image will thus be rendered once in each fragment of the element.
 
-      Note: Cloned margins can be <a href="#break-margins">truncated</a>
+      Note: Cloned margins are <a href="#break-margins">truncated</a>
+            on block-level boxes.
     </dd>
 
     <dt><dfn>slice</dfn>

css-break/Overview.html

@@ -80,7 +80,7 @@
    <h1 class="p-name no-ref" id="title">CSS Fragmentation Module Level 3</h1>
 
    <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Editor’s Draft,
-    <time class="dt-updated" datetime="2015-07-15">15 July 2015</time></span></h2>
+    <time class="dt-updated" datetime="2015-07-16">16 July 2015</time></span></h2>
 
    <div data-fill-with="spec-metadata">
     <dl>
@@ -1621,9 +1621,11 @@ <h3 class="heading settled" data-level="5.2" id="break-margins"><span class="sec
 
    <p>
     When an unforced break occurs between block-level boxes,
-    any margins adjoining the break truncate to the <a data-link-type="dfn" href="#remaining-fragmentainer-extent">remaining fragmentainer extent</a>.
+    any margins adjoining the break truncate to the <a data-link-type="dfn" href="#remaining-fragmentainer-extent">remaining fragmentainer extent</a> before the break,
+    and are truncated to zero after the break.
     When a forced break occurs there, adjoining margins before the break are truncated,
     but margins after the break are preserved.
+    <a href="#valdef-box-decoration-break-clone">Cloned margins</a> are always truncated to zero on block-level margins.
   </p>
 
 
@@ -1768,7 +1770,8 @@ <h3 class="heading settled" data-level="5.4" id="break-decoration"><span class="
       A no-repeat background image will thus be rendered once in each fragment of the element.
 
 
-     <p class="note" role="note">Note: Cloned margins can be <a href="#break-margins">truncated</a></p>
+     <p class="note" role="note">Note: Cloned margins are <a href="#break-margins">truncated</a>
+            on block-level boxes.</p>