fix(links): only preview and link known protocols

Only generate previews for http and https.
Only link to http, https, mailto, and tel.

Signed-off-by: Max <max@nextcloud.com>

cypress/e2e/nodes/Links.spec.js

@@ -116,6 +116,30 @@ describe('test link marks', function() {
 				.should('have.been.calledWith', link)
 		})
 
+		it('Handles typed in markdown links with text', () => {
+			const link = 'https://nextcloud.com/'
+			cy.insertLine(`[text](${link})`)
+			clickLink(link)
+			cy.get('.link-view-bubble .widget-default', { timeout: 10000 })
+				.find('.widget-default--name')
+				.contains('Nextcloud')
+			cy.get('.link-view-bubble a')
+				.should('have.attr', 'href', link)
+		})
+
+		it('Leaves out link to other protocols', () => {
+			const link = 'other://protocol'
+			cy.insertLine(`[text](${link})`)
+			cy.getContent()
+				.find(`a[href*="${link}"]`)
+				.should('not.exist')
+			clickLink('#')
+			cy.get('.link-view-bubble__title', { timeout: 10000 })
+				.contains('other://protocol')
+			cy.get('.link-view-bubble a')
+				.should('not.exist')
+		})
+
 	})
 
 	describe('autolink', function() {

src/components/Link/LinkBubbleView.vue

@@ -74,7 +74,7 @@
 		</div>
 
 		<!-- link preview -->
-		<NcReferenceList v-else-if="href"
+		<NcReferenceList v-else-if="showPreview"
 			ref="referencelist"
 			:text="sanitizedHref"
 			:limit="1"
@@ -97,6 +97,8 @@ import PencilIcon from 'vue-material-design-icons/Pencil.vue'
 
 import CopyToClipboardMixin from '../../mixins/CopyToClipboardMixin.js'
 
+const PROTOCOLS_WITH_PREVIEW = ['http:', 'https:']
+
 export default {
 	name: 'LinkBubbleView',
 
@@ -162,6 +164,11 @@ export default {
 		title() {
 			return this.referenceTitle ? this.referenceTitle : this.sanitizedHref
 		},
+
+		showPreview() {
+			const url = new URL(this.href, window.location)
+			return this.href && PROTOCOLS_WITH_PREVIEW.includes(url.protocol)
+		},
 	},
 
 	watch: {