[FIX] web_editor: unexpected copy paste behaviour of link

Current behaviour before commit:

-When pasting copied content from editor inside
link inserts text with HTML content, in result
the pasted content seems isolated from the link.

e.g. <a href="#">te[]st</a>
	+ pasting <h1>123</h1>  <=>
	<a href="#">te<h1>123</h1>st</a>

Desired behaviour after commit:

-Now only text content is pasted which makes
pasted content as a part of the link.

e.g. <a href="#">te[]st</a>
	+ pasting <h1>123</h1>  <=>
	<a href="#">te123st</a>

closes odoo/odoo#134516

X-original-commit: 1cc3354b88658620c15fa18427b8725b6215337d
Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>

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

@@ -4638,7 +4638,12 @@ export class OdooEditor extends EventTarget {
                     }
                 });
             } else {
-                this._applyCommand('insert', clipboardElem);
+                if (closestElement(sel.anchorNode, 'a')) {
+                    this._applyCommand('insert', clipboardElem.textContent);
+                }
+                else {
+                    this._applyCommand('insert', clipboardElem);
+                }
             }
         } else {
             const text = ev.clipboardData.getData('text/plain');

addons/web_editor/static/src/js/editor/odoo-editor/test/spec/copyPaste.test.js

@@ -1548,6 +1548,15 @@ describe('Paste', () => {
                     contentAfter: `<p><a href="${url}">${url}</a> abc <a href="${videoUrl}">${videoUrl}</a> def <a href="${imgUrl}">${imgUrl}</a>[]</p>`,
                 });
             });
+            it('should paste plain text inside non empty link', async () => {
+                await testEditor(BasicEditor, {
+                    contentBefore: '<p><a href="#">a[]b</a></p>',
+                    stepFunction: async editor => {
+                        await pasteHtml(editor, '<span>123</span>');
+                    },
+                    contentAfter: '<p><a href="#">a123[]b</a></p>',
+                });
+            });
         });
         describe('range not collapsed', async () => {
             it('should paste and transform an URL in a p', async () => {