From 3b797c6a9e810a83563d556b3e804a9357d6d294 Mon Sep 17 00:00:00 2001
From: Szymon Cofalik <s.cofalik@cksource.com>
Date: Wed, 4 Oct 2017 13:11:21 +0200
Subject: [PATCH] Changed: Prevent removing attribute element from empty block
 element with stored selection attribute.

---
 .../model-selection-to-view-converters.js      | 18 +++++++++++++-----
 src/view/writer.js                             | 10 ++++++++++
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/conversion/model-selection-to-view-converters.js b/src/conversion/model-selection-to-view-converters.js
index 71e4d5023..529e766b7 100644
--- a/src/conversion/model-selection-to-view-converters.js
+++ b/src/conversion/model-selection-to-view-converters.js
@@ -83,11 +83,14 @@ export function convertCollapsedSelection() {
 		}
 
 		const modelPosition = selection.getFirstPosition();
-		const viewPosition = conversionApi.mapper.toViewPosition( modelPosition );
-		const brokenPosition = viewWriter.breakAttributes( viewPosition );
+		let viewPosition = conversionApi.mapper.toViewPosition( modelPosition );
+
+		if ( !modelPosition.parent.isEmpty ) {
+			viewPosition = viewWriter.breakAttributes( viewPosition );
+		}
 
 		conversionApi.viewSelection.removeAllRanges();
-		conversionApi.viewSelection.addRange( new ViewRange( brokenPosition, brokenPosition ) );
+		conversionApi.viewSelection.addRange( new ViewRange( viewPosition, viewPosition ) );
 	};
 }
 
@@ -257,9 +260,14 @@ export function clearAttributes() {
 		for ( const range of conversionApi.viewSelection.getRanges() ) {
 			// Not collapsed selection should not have artifacts.
 			if ( range.isCollapsed ) {
+				const viewPosition = range.start;
+				const modelPosition = conversionApi.mapper.toModelPosition( viewPosition );
+
 				// Position might be in the node removed by the view writer.
-				if ( range.end.parent.document ) {
-					viewWriter.mergeAttributes( range.start );
+				if ( viewPosition.parent.document && modelPosition ) {
+					if ( !modelPosition.parent.isEmpty ) {
+						viewWriter.mergeAttributes( viewPosition );
+					}
 				}
 			}
 		}
diff --git a/src/view/writer.js b/src/view/writer.js
index ffbd49b07..2d2d3072f 100644
--- a/src/view/writer.js
+++ b/src/view/writer.js
@@ -540,6 +540,16 @@ export function wrapPosition( position, attribute ) {
 		return movePositionToTextNode( Position.createFromPosition( position ) );
 	}
 
+	// Put position inside node, at the end of it, if previous node is similar.
+	if ( position.nodeBefore && position.nodeBefore.isSimilar( attribute ) ) {
+		return movePositionToTextNode( Position.createAt( position.nodeBefore, 'end' ) );
+	}
+
+	// Put position inside node, at the beginning of it, if next node is similar.
+	if ( position.nodeAfter && position.nodeAfter.isSimilar( attribute ) ) {
+		return movePositionToTextNode( Position.createAt( position.nodeAfter, 0 ) );
+	}
+
 	// When position is inside text node - break it and place new position between two text nodes.
 	if ( position.parent.is( 'text' ) ) {
 		position = breakTextNode( position );