[FIX] web_editor : ensure break line consistency on delete

When delete backward/forward OR deleteRange,
we need to ensure the break lines stay consistent with the user action.

Some cases where not handled correctly.

Mainly when a <p> tags was removed and not directly adjacent to another block element.
In those case we kept too much or too little break lines.

@see tests added in `test/spec/editor.test.js`

task-2604627

X-original-commit: 9f14422ffceadd48b76ff460e4080e0cf5bc6fa2
Part-of: odoo/odoo#89210

addons/web_editor/static/lib/odoo-editor/src/OdooEditor.js

@@ -1312,7 +1312,9 @@ export class OdooEditor extends EventTarget {
         let start = range.startContainer;
         let end = range.endContainer;
         // Let the DOM split and delete the range.
-        const doJoin = closestBlock(start) !== closestBlock(range.commonAncestorContainer);
+        const doJoin =
+            closestBlock(start) !== closestBlock(range.commonAncestorContainer) ||
+            closestBlock(end) !== closestBlock(range.commonAncestorContainer) ;
         let next = nextLeaf(end, this.editable);
         const splitEndTd = closestElement(end, 'td') && end.nextSibling;
         const contents = range.extractContents();

addons/web_editor/static/lib/odoo-editor/src/commands/deleteBackward.js

@@ -163,6 +163,7 @@ HTMLElement.prototype.oDeleteBackward = function (offset, alreadyMoved = false,
     }
 
     let node = this.childNodes[offset];
+    const nextSibling = this.nextSibling;
     let currentNodeIndex = offset;
 
     // `offsetLimit` will ensure we never move nodes that were not initialy in the element
@@ -194,6 +195,20 @@ HTMLElement.prototype.oDeleteBackward = function (offset, alreadyMoved = false,
         const { cType } = getState(cursorNode, cursorOffset, DIRECTIONS.LEFT);
         if (cType & CTGROUPS.BLOCK && (!alreadyMoved || cType === CTYPES.BLOCK_OUTSIDE)) {
             cursorNode.oDeleteBackward(cursorOffset, alreadyMoved, cursorOffset + currentNodeIndex - offset);
+        } else if (!alreadyMoved) {
+            // When removing a block node adjacent to a inline node,
+            // we need to ensure the block node induced line break are kept with a <br>.
+            // ex : <div>a<span>b</span><p>[]c</p>d</div> => deleteBakward
+            // =>   <div>a<span>b</span>[]c<br>d</div>
+            // In this case we cannot simply merge the <p> content into the div parent
+            // or we would loose the line break located after the <p>.
+            const cursorNodeNode = cursorNode.childNodes[cursorOffset];
+            const cursorNodeRightNode = cursorNodeNode ? cursorNodeNode.nextSibling : undefined;
+            if (cursorNodeRightNode &&
+                cursorNodeRightNode.nodeType === Node.TEXT_NODE &&
+                nextSibling === cursorNodeRightNode) {
+                moveDest[0].insertBefore(document.createElement('br'), cursorNodeRightNode);
+            }
         }
     }
 };