Account for more cases

src/librustdoc/clean/inline.rs

@@ -1,6 +1,5 @@
 //! Support for inlining external documentation into the current AST.
 
-use std::collections::VecDeque;
 use std::iter::once;
 use std::sync::Arc;
 
@@ -425,15 +424,16 @@ crate fn build_impl(
     }
 
     // Return if the trait itself or any types of the generic parameters are doc(hidden).
-    let mut deque: VecDeque<&Type> = trait_.iter().collect();
-    while let Some(ty) = deque.pop_back() {
+    let mut stack: Vec<&Type> = trait_.iter().collect();
+    stack.push(&for_);
+    while let Some(ty) = stack.pop() {
         if let Some(did) = ty.def_id() {
             if cx.tcx.get_attrs(did).lists(sym::doc).has_word(sym::hidden) {
                 return;
             }
         }
         if let Some(generics) = ty.generics() {
-            deque.extend(generics);
+            stack.extend(generics);
         }
     }
 

src/test/rustdoc/auxiliary/cross-crate-hidden.rs

@@ -1,2 +1,5 @@
 #[doc(hidden)]
 pub enum HiddenType {}
+
+#[doc(hidden)]
+pub trait HiddenTrait {}

src/test/rustdoc/cross-crate-hidden.rs

@@ -4,7 +4,7 @@
 // aux-build:cross-crate-hidden.rs
 extern crate cross_crate_hidden;
 
-pub use ::cross_crate_hidden::HiddenType; // OK, not re-exported
+pub use ::cross_crate_hidden::{HiddenType, HiddenTrait}; // OK, not re-exported
 
 pub enum MyLibType {}
 
@@ -15,9 +15,21 @@ impl From<HiddenType> for MyLibType {
     }
 }
 
-// @!has foo/enum.MyLibType.html '//*[@id="impl-From%3COption%3COption%3COption%3COption%3CHiddenType%3E%3E%3E%3E%3E"]' 'impl From<Option<Option<Option<Option<HiddenType>>>>> for MyLibType'
-impl From<Option<Option<Option<Option<HiddenType>>>>> for MyLibType {
-    fn from(it: Option<Option<Option<Option<HiddenType>>>>) -> MyLibType {
+pub struct T<T>(T);
+
+// @!has foo/enum.MyLibType.html '//*[@id="impl-From%3CT%3CT%3CT%3CT%3CHiddenType%3E%3E%3E%3E%3E"]' 'impl From<T<T<T<T<HiddenType>>>>> for MyLibType'
+impl From<T<T<T<T<HiddenType>>>>> for MyLibType {
+    fn from(it: T<T<T<T<HiddenType>>>>) -> MyLibType {
         todo!()
     }
 }
+
+// @!has foo/enum.MyLibType.html '//*[@id="impl-HiddenTrait"]' 'impl HiddenTrait for MyLibType'
+impl HiddenTrait for MyLibType {}
+
+// @!has foo/struct.T.html '//*[@id="impl-From%3CMyLibType%3E"]' 'impl From<MyLibType> for T<T<T<T<HiddenType>>>>'
+impl From<MyLibType> for T<T<T<T<HiddenType>>>> {
+    fn from(it: MyLibType) -> T<T<T<T<HiddenType>>>> {
+        match it {}
+    }
+}