Post Navigation Link: Add border and spacing block support

docs/reference-guides/core-blocks.md

@@ -651,7 +651,7 @@ Displays the next or previous post link that is adjacent to the current post. ([
 
 -	**Name:** core/post-navigation-link
 -	**Category:** theme
--	**Supports:** color (background, link, text), interactivity (clientNavigation), typography (fontSize, lineHeight), ~~html~~, ~~reusable~~
+-	**Supports:** color (background, link, text), interactivity (clientNavigation), spacing (margin, padding), typography (fontSize, lineHeight), ~~html~~, ~~reusable~~
 -	**Attributes:** arrow, label, linkLabel, showTitle, taxonomy, textAlign, type
 
 ## Post Template

packages/block-library/src/post-navigation-link/block.json

@@ -57,7 +57,25 @@
 		},
 		"interactivity": {
 			"clientNavigation": true
+		},
+		"spacing": {
+			"margin": true,
+			"padding": true,
+			"__experimentalDefaultControls": {
+				"margin": false,
+				"padding": false
+			}
+		},
+		"__experimentalBorder": {
+			"radius": true,
+			"color": true,
+			"width": true,
+			"style": true
 		}
 	},
+	"selectors": {
+		"border": ".wp-block-post-navigation-link:not(:empty)",
+		"spacing": ".wp-block-post-navigation-link:not(:empty)"
+	},
 	"style": "wp-block-post-navigation-link"
 }

packages/block-library/src/post-navigation-link/index.php

@@ -118,7 +118,7 @@ function render_block_core_post_navigation_link( $attributes, $content ) {
 
 	return sprintf(
 		'<div %1$s>%2$s</div>',
-		$wrapper_attributes,
+		! empty( $content ) ? $wrapper_attributes : "class=\"post-navigation-link {$classes}\"",
 		$content
 	);
 }

packages/block-library/src/post-navigation-link/style.scss

@@ -1,4 +1,6 @@
 .wp-block-post-navigation-link {
+	// This block has customizable padding, border-box makes that more predictable.
+	box-sizing: border-box;
 
 	.wp-block-post-navigation-link__arrow-previous {
 		display: inline-block;