From 44b489f27a92e7e9662f27bcebb66662f4772247 Mon Sep 17 00:00:00 2001
From: Nixon Enraght-Moony <nixon.emoony@gmail.com>
Date: Tue, 9 Aug 2022 15:52:18 +0100
Subject: [PATCH] rustdoc: Mark imported items as retained

Fixes a bug where impl of items that were imported from a private module
would be striped

Fixes #100252
Fixes #100242
---
 src/librustdoc/passes/stripper.rs             | 12 +++++++++-
 .../rustdoc-json/impls/import_from_private.rs | 24 +++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 src/test/rustdoc-json/impls/import_from_private.rs

diff --git a/src/librustdoc/passes/stripper.rs b/src/librustdoc/passes/stripper.rs
index 0d419042a10a4..93beaaa92a775 100644
--- a/src/librustdoc/passes/stripper.rs
+++ b/src/librustdoc/passes/stripper.rs
@@ -84,7 +84,17 @@ impl<'a> DocFolder for Stripper<'a> {
             }
 
             // handled in the `strip-priv-imports` pass
-            clean::ExternCrateItem { .. } | clean::ImportItem(..) => {}
+            clean::ExternCrateItem { .. } => {}
+            clean::ImportItem(ref imp) => {
+                // Because json doesn't inline imports from private modules, we need to mark
+                // the imported item as retained so it's impls won't be stripped.i
+                //
+                // FIXME: Is it necessary to check for json output here: See
+                // https://github.com/rust-lang/rust/pull/100325#discussion_r941495215
+                if let Some(did) = imp.source.did && self.is_json_output {
+                    self.retained.insert(did.into());
+                }
+            }
 
             clean::ImplItem(..) => {}
 
diff --git a/src/test/rustdoc-json/impls/import_from_private.rs b/src/test/rustdoc-json/impls/import_from_private.rs
new file mode 100644
index 0000000000000..ef4d8aa39f88c
--- /dev/null
+++ b/src/test/rustdoc-json/impls/import_from_private.rs
@@ -0,0 +1,24 @@
+// https://github.com/rust-lang/rust/issues/100252
+
+#![feature(no_core)]
+#![no_core]
+
+mod bar {
+    // @set baz = import_from_private.json "$.index[*][?(@.kind=='struct')].id"
+    pub struct Baz;
+    // @set impl = - "$.index[*][?(@.kind=='impl')].id"
+    impl Baz {
+        // @set doit = - "$.index[*][?(@.kind=='method')].id"
+        pub fn doit() {}
+    }
+}
+
+// @set import = - "$.index[*][?(@.kind=='import')].id"
+pub use bar::Baz;
+
+// FIXME(adotinthevoid): Use hasexact once #99474 lands
+
+// @has - "$.index[*][?(@.kind=='module')].inner.items[*]" $import
+// @is  - "$.index[*][?(@.kind=='import')].inner.id" $baz
+// @has - "$.index[*][?(@.kind=='struct')].inner.impls[*]" $impl
+// @has - "$.index[*][?(@.kind=='impl')].inner.items[*]" $doit