[css-break] Specify entrapment of forced breaks by monolithic elements.

Author: fantasai

css-break/Overview.bs

@@ -571,9 +571,6 @@ Possible Break Points</h3>
     <dt id="btw-lines">Class B</dt>
     <dd>
       Between line boxes inside a block container box.
-
-      Note: Since line boxes cannot be broken,
-      ''inline-block'' and ''inline-table'' boxes cannot be fragmented.
     </dd>
     <dt id="end-block">Class C</dt>
     <dd>
@@ -602,13 +599,24 @@ Possible Break Points</h3>
     scrollable elements, or a single line of text content.
     Such content is considered <dfn>monolithic</dfn>:
     it contains no possible break points.
-    In addition to any content which is not fragmentable,
+    Any forced breaks within such boxes
+    therefore cannot split the box,
+    and must therefore also be ignored by the box’s own fragmentation context.
+
+  <p>
+    In addition to any content which is not generally fragmentable,
     UAs may consider as <i>monolithic</i> any elements with
     'overflow' set to ''overflow/auto'' or ''overflow/scroll'' and
     any elements with ''overflow: hidden'' and a non-''height/auto''
     <a href="http://www.w3.org/TR/css3-writing-modes/#block-size">logical height</a>
     (and no specified maximum logical height).
 
+  <p>
+    Since line boxes contain no possible break points,
+    ''inline-block'' and ''inline-table'' boxes
+    (and other inline-level <a>display types</a> that establish a new <a>formatting context</a>)
+    may also be considered <a>monolithic</a>.
+
 <h3 id="break-types">
 Types of Breaks</h3>
 

css-break/Overview.html

@@ -538,9 +538,7 @@ <h3 class="heading settled" data-level="4.1" id="possible-breaks"><span class="s
           multi-column column boxes. 
      </dl>
     <dt id="btw-lines"><a class="self-link" href="#btw-lines"></a>Class B
-    <dd>
-      Between line boxes inside a block container box. 
-     <p class="note" role="note">Note: Since line boxes cannot be broken, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-display-3/#valdef-display-inline-block">inline-block</a> and <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-display-3/#valdef-display-inline-table">inline-table</a> boxes cannot be fragmented.</p>
+    <dd> Between line boxes inside a block container box. 
     <dt id="end-block"><a class="self-link" href="#end-block"></a>Class C
     <dd> Between the content edge of a block container box and the outer edges of its
       child content (margin edges of block-level children or line box
@@ -557,9 +555,15 @@ <h3 class="heading settled" data-level="4.1" id="possible-breaks"><span class="s
     scrollable elements, or a single line of text content.
     Such content is considered <dfn data-dfn-type="dfn" data-noexport="" id="monolithic">monolithic<a class="self-link" href="#monolithic"></a></dfn>:
     it contains no possible break points.
-    In addition to any content which is not fragmentable,
+    Any forced breaks within such boxes
+    therefore cannot split the box,
+    and must therefore also be ignored by the box’s own fragmentation context. </p>
+   <p> In addition to any content which is not generally fragmentable,
     UAs may consider as <a data-link-type="dfn" href="#monolithic">monolithic</a> any elements with <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-overflow-3/#propdef-overflow">overflow</a> set to <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-overflow-3/#valdef-overflow-auto">auto</a> or <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-overflow-3/#valdef-overflow-scroll">scroll</a> and
     any elements with <a class="css" data-link-type="propdesc" href="https://drafts.csswg.org/css-overflow-3/#propdef-overflow">overflow: hidden</a> and a non-<span class="css">auto</span> <a href="http://www.w3.org/TR/css3-writing-modes/#block-size">logical height</a> (and no specified maximum logical height). </p>
+   <p> Since line boxes contain no possible break points, <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-display-3/#valdef-display-inline-block">inline-block</a> and <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/css-display-3/#valdef-display-inline-table">inline-table</a> boxes
+    (and other inline-level <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#display-type">display types</a> that establish a new <a data-link-type="dfn" href="https://drafts.csswg.org/css-display-3/#formatting-context">formatting context</a>)
+    may also be considered <a data-link-type="dfn" href="#monolithic">monolithic</a>. </p>
    <h3 class="heading settled" data-level="4.2" id="break-types"><span class="secno">4.2. </span><span class="content"> Types of Breaks</span><a class="self-link" href="#break-types"></a></h3>
    <p> There are different types of breaks in CSS, defined based on the type of
     fragmentainers they span: </p>
@@ -1131,6 +1135,8 @@ <h3 class="no-num heading settled" id="index-defined-elsewhere"><span class="con
    <li>
     <a data-link-type="biblio" href="#biblio-css-display-3">[css-display-3]</a> defines the following terms:
     <ul>
+     <li><a href="https://drafts.csswg.org/css-display-3/#display-type">display type</a>
+     <li><a href="https://drafts.csswg.org/css-display-3/#formatting-context">formatting context</a>
      <li><a href="https://drafts.csswg.org/css-display-3/#valdef-display-inline-block">inline-block</a>
      <li><a href="https://drafts.csswg.org/css-display-3/#valdef-display-inline-table">inline-table</a>
     </ul>