[css-scroll-snap] Per WG resolution, when navigating to a fragment: UAs must use snap positions if snapping is on, may use them if snapping is off, should pay attention to scroll-snap-margin regardless. Fixes #1707.

Author: tabatkins

css-scroll-snap-1/Overview.bs

@@ -516,6 +516,13 @@ Scroll Snapping Area: the 'scroll-snap-margin' property {#scroll-snap-margin}
     Note: This ensures that the <a>scroll snap area</a> is always rectangular
     and axis-aligned to the <a>scroll container’s</a> coordinate space.
 
+    If a page is navigated to a fragment that defines a target element
+    (one that would be matched by '':target'',
+    or the target of {{scrollIntoView()}}),
+    the UA should use the element's <a>scroll snap area</a>,
+    rather than just its border box,
+    to determine which area of the <a>scrollable overflow region</a> to bring into view.
+
 <!--
    ███    ██       ████  ██████   ██    ██
   ██ ██   ██        ██  ██    ██  ███   ██
@@ -924,8 +931,9 @@ Choosing Snap Positions {#choosing}
         (one that would be matched by '':target'',
         or the target of {{Element/scrollIntoView()}}),
         and that element defines some <a>snap positions</a>,
-        the user agent should <a>snap</a> to one of that element’s <a>snap positions</a>.
-        The user agent may do this even when the <a>scroll container</a> has ''scroll-snap-type: none''.
+        the user agent must <a>snap</a> to one of that element’s <a>snap positions</a>
+        if its nearest <a>scroll container</a> is a <a>scroll snap container</a>.
+        The user agent <em>may</em> also do this even when the <a>scroll container</a> has ''scroll-snap-type: none''.
 
 <!--
 ██        ███████  ██    ██  ██████   ██     ██    ███    ██    ██ ████████   ██████
@@ -1085,6 +1093,19 @@ Acknowledgements {#acknowledgements}
 Changes {#changes}
 ==================
 
+Changes Since 24 August 2017 CR {#changes-20170824}
+---------------------------------------------------
+
+    Changes since the <a href="https://www.w3.org/TR/2017/CR-css-scroll-snap-1-20170824/">24 August 2017 Candidate Recommendation</a> include:
+
+    * '':target''/{{scrollIntoView()}}/etc must use snap positions if snapping is turned on,
+        and may use them even if it's off.
+    * '':target''/{{scrollIntoView()}}/etc should take 'scroll-snap-margin' into account,
+        regardless of whether snapping is turned on or not.
+
+Changes Since 20 October 2016 CR {#changes-20161020}
+----------------------------------------------------
+
 	Changes since the <a href="https://www.w3.org/TR/2016/CR-css-scroll-snap-1-20161020/">20 October 2016 Candidate Recommendation</a> include:
 
 	<ul>