Revert "Revert "Merge branch 'main' of https://github.com/w3c/csswg-d…

…rafts into main""

This reverts commit 9d14c23.  The
commit that it was reverting was actually fine; it was a merge, but
looked like it was bad because it had a large diff against the first
parent but it had no diff against the second (which was the relevant one
in a "linear history" of this repository).

bin/ua-capitalization.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+# This script automates a large part of making sure "user agent" is written in lower case.
+# Doing so is backed by the CSS-WG resolution recorded at https://logs.csswg.org/irc.w3.org/css/2021-04-08/#e1402191
+# After this script has run,
+# there can remain a few instances of the term being used.
+# Those will have to be fixed manually.
+# Run frequently to avoid cruft piling up.
+for FILE in "$@"
+do
+	sed -i -e "s/\([a-zA-Z,;]\) User Agent/\1 user agent/"\
+	    -e "s/Note: User Agent/Note: User agent/"\
+	    -e "s/\. User Agent/. User agent/" $FILE
+done
+echo "Remaining instances of 'User Agent':"
+grep -R "User Agent" $@

css-2017/Overview.bs

@@ -431,7 +431,7 @@ CSS Profiles</h3>
 
 	In the past, the Working Group published a few Profiles,
 	which were meant to define the minimal subset of CSS
-	that various classes of User Agents were expected to support.
+	that various classes of user agents were expected to support.
 
 	This effort has been discontinued,
 	as the Working Group was not finding it effective or useful,

css-2018/Overview.bs

@@ -459,7 +459,7 @@ CSS Profiles</h3>
 
 	In the past, the Working Group published a few Profiles,
 	which were meant to define the minimal subset of CSS
-	that various classes of User Agents were expected to support.
+	that various classes of user agents were expected to support.
 
 	This effort has been discontinued,
 	as the Working Group was not finding it effective or useful,

css-2020/Overview.bs

@@ -525,7 +525,7 @@ CSS Profiles</h3>
 
 	In the past, the Working Group published a few Profiles,
 	which were meant to define the minimal subset of CSS
-	that various classes of User Agents were expected to support.
+	that various classes of user agents were expected to support.
 
 	This effort has been discontinued,
 	as the Working Group was not finding it effective or useful,

css-align-3/Overview.bs

@@ -806,9 +806,9 @@ Overflow Alignment: the ''safe'' and ''unsafe'' keywords and scroll safety limit
 				</div>
 			</div>
 			<figcaption>
-				The items in the figure on the right all strictly centered,
+				The items in the figure on the left are all strictly centered,
 				even if the one that is too long to fit overflows on both sides,
-				while those in the figure on the left are centered unless they overflow,
+				while those in the figure on the right are centered unless they overflow,
 				in which case all the overflow goes off the end edge.
 				If the container was placed
 				against the left edge of the page,

css-backgrounds-3/Overview.bs

@@ -97,6 +97,9 @@ Value Definitions</h3>
   using the <a href="https://www.w3.org/TR/css-values-3/#value-defs">value definition syntax</a> from [[!CSS-VALUES-3]].
   Value types not defined in this specification are defined in CSS Values &amp; Units [[!CSS-VALUES-3]].
   Combination with other CSS modules may expand the definitions of these value types.
+  For example, combining with <a href="https://www.w3.org/TR/css-images/">CSS Images</a>
+  allows for using CSS gradients as 'background-image' or 'border-image' values.
+  [[CSS-IMAGES-3]]
 
   In addition to the property-specific values listed in their definitions,
   all properties defined in this specification
@@ -287,9 +290,10 @@ controls for image display.
 <div class="example">
 <p>Some examples specifying background images:</p>
 <pre>
-body { background-image: url("marble.svg") }
+html { background-image: url("marble.svg") }
 p { background-image: none }
 div { background-image: url(tl.png), url(tr.png) }
+main { background-image: radial-gradient(at bottom right, transparent, white); }
 </pre>
 </div>
 
@@ -1260,14 +1264,9 @@ in order to allow styling of the canvas
 CSS propagates the background of the root element
 (or, in the case of HTML, the &lt;body&gt; element)
 as described below.
-However, if no boxes are generated for the element whose background
-would be used for the canvas
-(for example, if the root element has ''display: none''),
-then the canvas background is transparent.
-
-<p class=note>Note that an element might be invisible, but still generate boxes.
-For example, if the element has ''visibility: hidden'' but not ''display: none'',
-boxes <em>are</em> generated for it and its background <em>is</em> used for the canvas.
+However, the element whose background would be used for the canvas
+is ''display: none'',
+then the [=canvas background=] is transparent.
 
 <p>If the [=canvas background=] is not opaque,
 the <dfn export>canvas surface</dfn> below it shows through.
@@ -2977,7 +2976,7 @@ module.
 
 <dl>
 <dt><dfn>UA</dfn>
-<dt><dfn id="user-agent">User Agent</dfn>
+<dt><dfn id="user-agent">user agent</dfn>
 <dd>
 <p>A program that reads and/or writes CSS style sheets on behalf of a
 user in either or both of these categories: programs whose purpose is
@@ -3040,6 +3039,16 @@ The lists below describe which features from this specification are in each leve
 <h2 id="changes">
 Changes</h2>
 
+<h3 id="changes-2020-12">
+Changes since the 22 December 2020 Candidate Recommendation Snapshot</h3>
+
+<ul>
+  <li>Clarified that the rule about not propagating backgrounds from the root
+    when it doesn't generate boxes only applies to ''display: none'',
+    not ''display: contents''.
+    (<a href="https://github.com/w3c/csswg-drafts/issues/3779">Issue 3779</a>)
+</ul>
+
 <h3 id="changes-2017-10">
 Changes since the 17 October 2017 Candidate Recommendation</h3>
 

css-break-3/Overview.bs

@@ -273,7 +273,7 @@ Breaks Between Boxes: the 'break-before' and 'break-after' properties</h3>
 
   <p>
     Values for 'break-before' and 'break-after' are defined in the sub-sections below.
-    User Agents must apply these properties to boxes in the normal flow of the <a>fragmentation root</a>.
+    User agents must apply these properties to boxes in the normal flow of the <a>fragmentation root</a>.
     User agents should also apply these properties to floated boxes
     whose containing block is in the normal flow of the root fragmented element.
     User agents may also apply these properties to other boxes.

css-break-4/Overview.bs

@@ -265,7 +265,7 @@ Breaks Between Boxes: the 'break-before' and 'break-after' properties</h3>
 	indicate that content should be kept together.
 
 	Values for 'break-before' and 'break-after' are defined in the sub-sections below.
-	User Agents must apply these properties to boxes in the normal flow of the <a>fragmentation root</a>.
+	User agents must apply these properties to boxes in the normal flow of the <a>fragmentation root</a>.
 	User agents should also apply these properties to floated boxes
 	whose containing block is in the normal flow of the root fragmented element.
 	User agents may also apply these properties to other boxes.