Add regression test for rust-lang#81141

Author: GuillaumeGomez

tests/rustdoc/issue-81141-private-reexport-in-public-api.rs

@@ -0,0 +1,34 @@
+// This test ensures that if a private re-export is present in a public API, it'll be
+// replaced by the first public item in the re-export chain or by the private item.
+
+#![crate_name = "foo"]
+
+use crate::bar::Bar as Alias;
+
+pub use crate::bar::Bar as Whatever;
+use crate::Whatever as Whatever2;
+use crate::Whatever2 as Whatever3;
+pub use crate::bar::Inner as Whatever4;
+
+mod bar {
+    pub struct Bar;
+    pub use self::Bar as Inner;
+}
+
+// @has 'foo/fn.bar.html'
+// @has - '//*[@class="rust item-decl"]/code' 'pub fn bar() -> Bar'
+pub fn bar() -> Alias {
+    Alias
+}
+
+// @has 'foo/fn.bar2.html'
+// @has - '//*[@class="rust item-decl"]/code' 'pub fn bar2() -> Whatever'
+pub fn bar2() -> Whatever3 {
+    Whatever
+}
+
+// @has 'foo/fn.bar3.html'
+// @has - '//*[@class="rust item-decl"]/code' 'pub fn bar3() -> Whatever4'
+pub fn bar3() -> Whatever4 {
+    Whatever
+}