[BUGFIX] Avoid prev/next arrows if only 1 system news is shown

If only one system news is shown, it makes no sense to render arrows
to switch to other news records. Therefore those should only be
shown if there are at least 2 records.

Resolves: #85322
Releases: master, 8.7
Change-Id: I636b90121729bb2f12c2313a3cb7e8b858367970
Reviewed-on: https://review.typo3.org/57275


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Riccardo De Contardi <erredeco@gmail.com>
Reviewed-by: Guido Schmechel <guido.schmechel@brandung.de>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>

typo3/sysext/backend/Resources/Private/Partials/LoginNews.html

@@ -9,13 +9,15 @@
 				</div>
 			</f:for>
 		</div>
-		<a class="left typo3-login-carousel-control" href="#loginNews" role="button" data-slide="prev">
+		<f:if condition="{loginNewsItems -> f:count()} > 1">
+			<a class="left typo3-login-carousel-control" href="#loginNews" role="button" data-slide="prev">
 			<i class="fa fa-angle-left"></i>
 			<span class="sr-only"><f:translate key="login.news.previous" /></span>
-		</a>
-		<a class="right typo3-login-carousel-control" href="#loginNews" role="button" data-slide="next">
-			<i class="fa fa-angle-right"></i>
-			<span class="sr-only"><f:translate key="login.news.next" /></span>
-		</a>
+			</a>
+			<a class="right typo3-login-carousel-control" href="#loginNews" role="button" data-slide="next">
+				<i class="fa fa-angle-right"></i>
+				<span class="sr-only"><f:translate key="login.news.next" /></span>
+			</a>
+		</f:if>
 	</div>
 </f:if>