Dont clobber `as ..` rename in import suggestion

5 files changed, 55 insertions, 5 deletions

diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 2e28dad52c7..c8b96aae7a6 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -161,6 +161,7 @@ impl<'a> Resolver<'a> {
                     found_use,
                     DiagnosticMode::Normal,
                     path,
+                    None,
                 );
                 err.emit();
             } else if let Some((span, msg, sugg, appl)) = suggestion {
@@ -690,6 +691,7 @@ impl<'a> Resolver<'a> {
                         FoundUse::Yes,
                         DiagnosticMode::Pattern,
                         vec![],
+                        None,
                     );
                 }
                 err
@@ -1344,6 +1346,7 @@ impl<'a> Resolver<'a> {
             FoundUse::Yes,
             DiagnosticMode::Normal,
             vec![],
+            None,
         );
 
         if macro_kind == MacroKind::Derive && (ident.name == sym::Send || ident.name == sym::Sync) {
@@ -2325,6 +2328,7 @@ pub(crate) fn import_candidates(
     use_placement_span: Option<Span>,
     candidates: &[ImportSuggestion],
     mode: DiagnosticMode,
+    append: Option<&str>,
 ) {
     show_candidates(
         session,
@@ -2336,6 +2340,7 @@ pub(crate) fn import_candidates(
         FoundUse::Yes,
         mode,
         vec![],
+        append,
     );
 }
 
@@ -2353,10 +2358,12 @@ fn show_candidates(
     found_use: FoundUse,
     mode: DiagnosticMode,
     path: Vec<Segment>,
+    append: Option<&str>,
 ) {
     if candidates.is_empty() {
         return;
     }
+    let append = append.unwrap_or("");
 
     let mut accessible_path_strings: Vec<(String, &str, Option<DefId>, &Option<String>)> =
         Vec::new();
@@ -2417,7 +2424,7 @@ fn show_candidates(
                 // produce an additional newline to separate the new use statement
                 // from the directly following item.
                 let additional_newline = if let FoundUse::Yes = found_use { "" } else { "\n" };
-                candidate.0 = format!("{}{};\n{}", add_use, &candidate.0, additional_newline);
+                candidate.0 = format!("{add_use}{}{append};\n{additional_newline}", &candidate.0);
             }
 
             err.span_suggestions(
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index b3593fc9e47..d99c1cb6d3c 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -547,15 +547,16 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
 
             if let Some(candidates) = &err.candidates {
                 match &import.kind {
-                    ImportKind::Single { nested: false, .. } => import_candidates(
+                    ImportKind::Single { nested: false, source, target, .. } => import_candidates(
                         self.r.session,
                         &self.r.untracked.source_span,
                         &mut diag,
                         Some(err.span),
                         &candidates,
                         DiagnosticMode::Import,
+                        (source != target).then(|| format!(" as {target}")).as_deref(),
                     ),
-                    ImportKind::Single { nested: true, .. } => {
+                    ImportKind::Single { nested: true, source, target, .. } => {
                         import_candidates(
                             self.r.session,
                             &self.r.untracked.source_span,
@@ -563,6 +564,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
                             None,
                             &candidates,
                             DiagnosticMode::Normal,
+                            (source != target).then(|| format!(" as {target}")).as_deref(),
                         );
                     }
                     _ => {}
diff --git a/src/test/ui/imports/bad-import-with-rename.rs b/src/test/ui/imports/bad-import-with-rename.rs
new file mode 100644
index 00000000000..ffe56916f92
--- /dev/null
+++ b/src/test/ui/imports/bad-import-with-rename.rs
@@ -0,0 +1,16 @@
+mod A {
+    pub type B = ();
+    pub type B2 = ();
+}
+
+mod C {
+    use crate::D::B as _;
+    //~^ ERROR unresolved import `crate::D::B`
+
+    use crate::D::B2;
+    //~^ ERROR unresolved import `crate::D::B2`
+}
+
+mod D {}
+
+fn main() {}
diff --git a/src/test/ui/imports/bad-import-with-rename.stderr b/src/test/ui/imports/bad-import-with-rename.stderr
new file mode 100644
index 00000000000..cace2a7a51c
--- /dev/null
+++ b/src/test/ui/imports/bad-import-with-rename.stderr
@@ -0,0 +1,25 @@
+error[E0432]: unresolved import `crate::D::B`
+  --> $DIR/bad-import-with-rename.rs:7:9
+   |
+LL |     use crate::D::B as _;
+   |         ^^^^^^^^^^^^^^^^ no `B` in `D`
+   |
+help: consider importing this type alias instead
+   |
+LL |     use A::B as _;
+   |         ~~~~~~~~~~
+
+error[E0432]: unresolved import `crate::D::B2`
+  --> $DIR/bad-import-with-rename.rs:10:9
+   |
+LL |     use crate::D::B2;
+   |         ^^^^^^^^^^^^ no `B2` in `D`
+   |
+help: consider importing this type alias instead
+   |
+LL |     use A::B2;
+   |         ~~~~~~
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0432`.
diff --git a/src/test/ui/test-attrs/inaccessible-test-modules.stderr b/src/test/ui/test-attrs/inaccessible-test-modules.stderr
index 0c16ecd4c86..17ea648aad6 100644
--- a/src/test/ui/test-attrs/inaccessible-test-modules.stderr
+++ b/src/test/ui/test-attrs/inaccessible-test-modules.stderr
@@ -19,8 +19,8 @@ LL | use test as y;
    |     ~~~~
 help: consider importing this module instead
    |
-LL | use test::test;
-   |     ~~~~~~~~~~~
+LL | use test::test as y;
+   |     ~~~~~~~~~~~~~~~~
 
 error: aborting due to 2 previous errors