From 4449cd60c7202dacf613793a7095b0237ea7d69e Mon Sep 17 00:00:00 2001
From: Andrew Duthie <andrew@andrewduthie.com>
Date: Thu, 6 Jun 2019 15:09:11 -0400
Subject: [PATCH 1/3] Block Editor: Disable block selection via tabIndex focus
 disabling

---
 .../src/components/block-list/block.js           | 16 +++++++++++++++-
 .../src/components/block-list/style.scss         | 10 ++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/packages/block-editor/src/components/block-list/block.js b/packages/block-editor/src/components/block-list/block.js
index aac68e2e6faa8..96497674c8fd5 100644
--- a/packages/block-editor/src/components/block-list/block.js
+++ b/packages/block-editor/src/components/block-list/block.js
@@ -400,6 +400,15 @@ function BlockListBlock( {
 		className
 	);
 
+	// By default, a block is focusable, which enables it to be set as the
+	// selected block when the user interacts within its content. Through
+	// assignment of its wrapper props, however, a block can opt-out of this
+	// behavior to effectively treat the block as a "pass-through", one which
+	// is not intended to be directly selected under normal circumstances.
+	// Often this occurs in the context of deep block nesting, where focus
+	// selection instead occurs by one of the ancestor blocks.
+	let isFocusable = true;
+
 	// Determine whether the block has props to apply to the wrapper.
 	let blockWrapperProps = wrapperProps;
 	if ( blockType.getEditWrapperProps ) {
@@ -407,6 +416,11 @@ function BlockListBlock( {
 			...blockWrapperProps,
 			...blockType.getEditWrapperProps( attributes ),
 		};
+
+		isFocusable = ! ( 'tabIndex' in blockWrapperProps ) || (
+			isFinite( blockWrapperProps.tabIndex ) &&
+			Number( blockWrapperProps.tabIndex ) !== '-1'
+		);
 	}
 	const blockElementId = `block-${ clientId }`;
 
@@ -452,7 +466,7 @@ function BlockListBlock( {
 			className={ wrapperClassName }
 			data-type={ name }
 			onTouchStart={ onTouchStart }
-			onFocus={ onFocus }
+			onFocus={ isFocusable ? onFocus : null }
 			onClick={ onTouchStop }
 			onKeyDown={ deleteOrInsertAfterWrapper }
 			tabIndex="0"
diff --git a/packages/block-editor/src/components/block-list/style.scss b/packages/block-editor/src/components/block-list/style.scss
index 8ee3558ddf639..45e6c948d6439 100644
--- a/packages/block-editor/src/components/block-list/style.scss
+++ b/packages/block-editor/src/components/block-list/style.scss
@@ -316,6 +316,16 @@
 		}
 	}
 
+	// Disable clickthrough overlay for blocks which aren't focusable, since
+	// overlay depends on dismissal by selection. This effectively treats the
+	// block as a "pass-through", one which is not intended to be selected
+	// through standard focus interactions.
+	&[tabindex="-1"],
+	&:not([tabindex]) {
+		> .block-editor-block-list__block-edit .block-editor-inner-blocks.has-overlay::after {
+			display: none;
+		}
+	}
 
 	// Alignments
 	&[data-align="left"],

From 0aa41cfe9db2f3f1cb0c9cb75bd263c9e753ac1c Mon Sep 17 00:00:00 2001
From: Andrew Duthie <andrew@andrewduthie.com>
Date: Thu, 6 Jun 2019 15:18:54 -0400
Subject: [PATCH 2/3] Block Library: Add pass-through wrapper prop for Column
 block

---
 packages/block-library/src/column/index.js | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/packages/block-library/src/column/index.js b/packages/block-library/src/column/index.js
index 250ce0bad65a4..2f6b98614f2c7 100644
--- a/packages/block-library/src/column/index.js
+++ b/packages/block-library/src/column/index.js
@@ -27,13 +27,20 @@ export const settings = {
 	},
 	getEditWrapperProps( attributes ) {
 		const { width } = attributes;
+
+		// A column should act as a "pass-through", meaning that it cannot be
+		// selected by typical focus interactions. A block becomes selected by
+		// virtue of its focus handler, and by nullifying its tabIndex, it will
+		// no longer handle focus events.
+		const props = { tabIndex: undefined };
+
 		if ( Number.isFinite( width ) ) {
-			return {
-				style: {
-					flexBasis: width + '%',
-				},
+			props.style = {
+				flexBasis: width + '%',
 			};
 		}
+
+		return props;
 	},
 	edit,
 	save,

From 0651a4524bd5f4a41fe7440f7b506b3b842e50ed Mon Sep 17 00:00:00 2001
From: Andrew Duthie <andrew@andrewduthie.com>
Date: Mon, 10 Jun 2019 09:41:47 -0400
Subject: [PATCH 3/3] Block Editor: Compare coerced tabIndex as number
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Grzegorz (Greg) Ziółkowski <grzegorz@gziolo.pl>
---
 packages/block-editor/src/components/block-list/block.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/block-editor/src/components/block-list/block.js b/packages/block-editor/src/components/block-list/block.js
index 96497674c8fd5..d5a70b040639d 100644
--- a/packages/block-editor/src/components/block-list/block.js
+++ b/packages/block-editor/src/components/block-list/block.js
@@ -419,7 +419,7 @@ function BlockListBlock( {
 
 		isFocusable = ! ( 'tabIndex' in blockWrapperProps ) || (
 			isFinite( blockWrapperProps.tabIndex ) &&
-			Number( blockWrapperProps.tabIndex ) !== '-1'
+			Number( blockWrapperProps.tabIndex ) !== -1
 		);
 	}
 	const blockElementId = `block-${ clientId }`;