[css-text-3] Add match-parent value to text-align-last so that it actually works as intended now that it's shorthanded by text-align. #2577 (comment)

Author: fantasai

css-text-3/Overview.bs

@@ -1338,7 +1338,7 @@ Shaping Across Intra-word Breaks</h3>
       and describes how the inline-level content of a block
       is aligned along the inline axis
       if the content does not completely fill the line box.
-      Values other than ''justify-all'' are assigned to 'text-align-all'
+      Values other than ''justify-all'' or ''match-parent'' are assigned to 'text-align-all'
       and reset 'text-align-last' to ''text-align-last/auto''.
 
     Values have the following meanings:
@@ -1370,7 +1370,7 @@ Shaping Across Intra-word Breaks</h3>
         Unless otherwise specified by 'text-align-last',
         the last line before a forced break or the end of the block is ''start''-aligned.
     <dt><dfn>justify-all</dfn></dt>
-      <dd>Sets both 'text-align' and 'text-align-last' to ''text-align/justify'',
+      <dd>Sets both 'text-align-all' and 'text-align-last' to ''text-align/justify'',
         forcing the last line to justify as well.
     <dt><dfn>match-parent</dfn></dt>
       <dd>This value behaves the same as ''inherit''
@@ -1380,6 +1380,8 @@ Shaping Across Intra-word Breaks</h3>
         (or the <a>initial containing block</a>’s, if there is no parent)
         'direction' value
         and results in a computed value of either 'left' or 'right'.
+        When specified on the 'text-align' shorthand,
+        sets both 'text-align-all' and 'text-align-last' to ''text-align/match-parent''.
     </dl>
 
     <p>A block of text is a stack of
@@ -1432,7 +1434,7 @@ Shaping Across Intra-word Breaks</h3>
 
     <pre class="propdef">
     Name: text-align-last
-    Value: auto | start | end | left | right | center | justify
+    Value: auto | start | end | left | right | center | justify | match-parent
     Initial: auto
     Applies to: block containers
     Inherited: yes