From 037d21393f17caf7bd2361be2f77551b63be8c25 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Darm=C3=BCntzel?= <martin@trivialanalog.de>
Date: Tue, 26 Dec 2023 19:30:23 +0100
Subject: [PATCH] docs: fixes an error during doc compilation

Building the docs raises an error:
UndefinedError("'logo' is undefined").

This fix checks if logo is defined.
---
 docs/source/_templates/pplnx_template/layout.html | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/docs/source/_templates/pplnx_template/layout.html b/docs/source/_templates/pplnx_template/layout.html
index 1bca49b8..6a0c2fe5 100644
--- a/docs/source/_templates/pplnx_template/layout.html
+++ b/docs/source/_templates/pplnx_template/layout.html
@@ -44,9 +44,11 @@
 <!-- MOBILE TOP BAR OVERLOAD -->
 {% block mobile_nav %}
     <i data-toggle="wy-nav-top" class="fa fa-bars"></i>
+    {% if logo %}
     <a href="{{ pathto(master_doc) }}">
-        <img src="{{ pathto('_static/' + logo, 1) }}" class="logo" alt="Logo"/>
-        </a>
+      <img src="{{ pathto('_static/' + logo, 1) }}" class="logo" alt="Logo"/>
+    </a>
+    {% endif %}
     <a href="{{ pathto(master_doc) }}">
         {{ project }}
     </a>