Respect html_show_sourcelink setting

https://www.sphinx-doc.org/en/master/usage/configuration.html#confval-html_show_sourcelink

Also simplify check to disable source linking on search page.

sphinx_rtd_theme/breadcrumbs.html

@@ -16,7 +16,18 @@
    {%- set display_gitlab = True %}
 {%- endif %}
 
-{%- set display_vcs_links = display_vcs_links if display_vcs_links is defined else True %}
+{%- set sourcelinks = True %}
+{%- if html_show_sourcelink is false %}
+   {#- https://www.sphinx-doc.org/en/master/usage/configuration.html#confval-html_show_sourcelink -#}
+   {%- set sourcelinks = False %}
+{%- elif hasdoc(pagename) is false %}
+   {#- disable for autogenerated pages -#}
+   {%- set sourcelinks = False %}
+{%- elif pagename == 'search' %}
+   {#- explicitly disable for search page -#}
+   {#- https://github.com/readthedocs/sphinx_rtd_theme/issues/934 -#}
+   {%- set sourcelinks = False %}
+{%- endif %}
 
 {#- Translators: This is an ARIA section label for page links, including previous/next page link and links to GitHub/GitLab/etc. -#}
 <div role="navigation" aria-label="{{ _('Page navigation') }}">
@@ -30,7 +41,7 @@
     {%- endblock %}
     {%- block breadcrumbs_aside %}
       <li class="wy-breadcrumbs-aside">
-        {%- if hasdoc(pagename) and display_vcs_links %}
+        {%- if sourcelinks %}
           {%- if display_github %}
             {%- if check_meta and 'github_url' in meta %}
               <!-- User defined GitHub URL -->

sphinx_rtd_theme/search.html

@@ -9,7 +9,6 @@
 #}
 {%- extends "layout.html" %}
 {% set title = _('Search') %}
-{% set display_vcs_links = False %}
 {%- block scripts %}
     {{ super() }}
     <script src="{{ pathto('_static/searchtools.js', 1) }}"></script>