rustdoc: remove unused .sub-logo-container DOM on non-source pages

Author: notriddle

src/librustdoc/html/templates/page.html

@@ -103,13 +103,15 @@ <h2 class="location"></h2> {#- -#}
     <main> {#- -#}
         <div class="width-limiter"> {#- -#}
             <div class="sub-container"> {#- -#}
+                {%- if page.css_class == "source" -%}
                 <a class="sub-logo-container" href="{{page.root_path|safe}}{{krate_with_trailing_slash|safe}}index.html"> {#- -#}
                     {%- if !layout.logo.is_empty()  %}
                         <img src="{{layout.logo}}" alt="logo"> {#- -#}
                     {%- else -%}
                         <img class="rust-logo" src="{{static_root_path|safe}}rust-logo{{page.resource_suffix}}.svg" alt="logo"> {#- -#}
                     {%- endif -%}
                 </a> {#- -#}
+                {%- endif -%}
                 <nav class="sub"> {#- -#}
                     <form class="search-form"> {#- -#}
                         <div class="search-container"> {#- -#}

src/test/rustdoc/logo-class-default.rs

@@ -1,4 +1,4 @@
 // Note: this test is paired with logo-class.rs.
 // @has logo_class_default/struct.SomeStruct.html '//*[@class="logo-container"]/img[@class="rust-logo"]' ''
-// @has logo_class_default/struct.SomeStruct.html '//*[@class="sub-logo-container"]/img[@class="rust-logo"]' ''
+// @has src/logo_class_default/logo-class-default.rs.html '//*[@class="sub-logo-container"]/img[@class="rust-logo"]' ''
 pub struct SomeStruct;

src/test/rustdoc/logo-class.rs

@@ -5,6 +5,6 @@
 // @has logo_class/struct.SomeStruct.html '//*[@class="logo-container"]/img[@src="https://raw.githubusercontent.com/sagebind/isahc/master/media/isahc.svg.png"]' ''
 // @!has logo_class/struct.SomeStruct.html '//*[@class="logo-container"]/img[@class="rust-logo"]' ''
 //
-// @has logo_class/struct.SomeStruct.html '//*[@class="sub-logo-container"]/img[@src="https://raw.githubusercontent.com/sagebind/isahc/master/media/isahc.svg.png"]' ''
-// @!has logo_class/struct.SomeStruct.html '//*[@class="sub-logo-container"]/img[@class="rust-logo"]' ''
+// @has src/logo_class/logo-class.rs.html '//*[@class="sub-logo-container"]/img[@src="https://raw.githubusercontent.com/sagebind/isahc/master/media/isahc.svg.png"]' ''
+// @!has src/logo_class/logo-class.rs.html '//*[@class="sub-logo-container"]/img[@class="rust-logo"]' ''
 pub struct SomeStruct;