Update rustdoc anonymous reexport test and add regression test for #108931

Author: GuillaumeGomez

tests/rustdoc/anonymous-reexport.rs

@@ -4,9 +4,13 @@
 
 // @has 'foo/index.html'
 // @has - '//*[@id="main-content"]' ''
-// We check that the only "h2" present is for "Bla".
-// @count - '//*[@id="main-content"]/h2' 1
+// We check that the only "h2" present are "Structs" (for "Bla") and "Re-exports".
+// @count - '//*[@id="main-content"]/h2' 2
 // @has - '//*[@id="main-content"]/h2' 'Structs'
+// @has - '//*[@id="main-content"]/h2' 'Re-exports'
+// The 3 re-exports.
+// @count - '//*[@id="main-content"]//*[@class="item-table"]//li//code' 3
+// The public struct.
 // @count - '//*[@id="main-content"]//a[@class="struct"]' 1
 
 mod ext {

tests/rustdoc/issue-108931-anonymous-reexport.rs

@@ -0,0 +1,21 @@
+// Ensuring that anonymous re-exports are always inlined.
+
+#![crate_name = "foo"]
+
+pub mod foo {
+    pub struct Foo;
+}
+
+mod bar {
+    pub struct Bar;
+}
+
+// @has 'foo/index.html'
+// We check that the only "h2" present are "Re-exports" and "Modules".
+// @count - '//*[@id="main-content"]/h2' 2
+// @has - '//*[@id="main-content"]/h2' 'Re-exports'
+// @has - '//*[@id="main-content"]/h2' 'Modules'
+// @has - '//*[@id="main-content"]//*[@class="item-table"]//li//code' 'pub use foo::Foo as _;'
+// @has - '//*[@id="main-content"]//*[@class="item-table"]//li//code' 'pub use bar::Bar as _;'
+pub use foo::Foo as _;
+pub use bar::Bar as _;