Rollup merge of rust-lang#121846 - bvanjoi:fix-121760, r=petrochenkov

only compare ambiguity item that have hard error

Fixes rust-lang#121760

An easy fix, r? `@petrochenkov`

compiler/rustc_resolve/src/imports.rs

@@ -8,8 +8,8 @@ use crate::errors::{
     ItemsInTraitsAreNotImportable,
 };
 use crate::Determinacy::{self, *};
-use crate::Namespace::*;
 use crate::{module_to_string, names_to_string, ImportSuggestion};
+use crate::{AmbiguityError, Namespace::*};
 use crate::{AmbiguityKind, BindingKey, ResolutionError, Resolver, Segment};
 use crate::{Finalize, Module, ModuleOrUniformRoot, ParentScope, PerNS, ScopeSet};
 use crate::{NameBinding, NameBindingData, NameBindingKind, PathResult, Used};
@@ -538,7 +538,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             .chain(indeterminate_imports.iter().map(|i| (true, i)))
         {
             let unresolved_import_error = self.finalize_import(*import);
-
             // If this import is unresolved then create a dummy import
             // resolution for it so that later resolve stages won't complain.
             self.import_dummy_binding(*import, is_indeterminate);
@@ -856,7 +855,9 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             ImportKind::Single { target_bindings, .. } => target_bindings[TypeNS].get(),
             _ => None,
         };
-        let prev_ambiguity_errors_len = self.ambiguity_errors.len();
+        let ambiguity_errors_len =
+            |errors: &Vec<AmbiguityError<'_>>| errors.iter().filter(|error| !error.warning).count();
+        let prev_ambiguity_errors_len = ambiguity_errors_len(&self.ambiguity_errors);
         let finalize = Finalize::with_root_span(import.root_id, import.span, import.root_span);
 
         // We'll provide more context to the privacy errors later, up to `len`.
@@ -870,7 +871,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             ignore_binding,
         );
 
-        let no_ambiguity = self.ambiguity_errors.len() == prev_ambiguity_errors_len;
+        let no_ambiguity =
+            ambiguity_errors_len(&self.ambiguity_errors) == prev_ambiguity_errors_len;
         import.vis.set(orig_vis);
         let module = match path_res {
             PathResult::Module(module) => {

tests/ui/imports/unresolved-seg-after-ambiguous.rs

@@ -0,0 +1,24 @@
+mod a {
+    mod b {
+        mod c {
+            pub struct E;
+        }
+
+        mod d {
+            #[derive(Debug)]
+            pub struct E;
+        }
+
+        pub use self::d::*;
+        pub use self::c::*;
+    }
+
+    pub use self::b::*;
+}
+
+use self::a::E::in_exist;
+//~^ ERROR: unresolved import `self::a::E`
+//~| WARNING: `E` is ambiguous
+//~| WARNING: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+
+fn main() {}

tests/ui/imports/unresolved-seg-after-ambiguous.stderr

@@ -0,0 +1,32 @@
+error[E0432]: unresolved import `self::a::E`
+  --> $DIR/unresolved-seg-after-ambiguous.rs:19:14
+   |
+LL | use self::a::E::in_exist;
+   |              ^ `E` is a struct, not a module
+
+warning: `E` is ambiguous
+  --> $DIR/unresolved-seg-after-ambiguous.rs:19:14
+   |
+LL | use self::a::E::in_exist;
+   |              ^ ambiguous name
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #114095 <https://github.com/rust-lang/rust/issues/114095>
+   = note: ambiguous because of multiple glob imports of a name in the same module
+note: `E` could refer to the struct imported here
+  --> $DIR/unresolved-seg-after-ambiguous.rs:13:17
+   |
+LL |         pub use self::c::*;
+   |                 ^^^^^^^^^^
+   = help: consider adding an explicit import of `E` to disambiguate
+note: `E` could also refer to the struct imported here
+  --> $DIR/unresolved-seg-after-ambiguous.rs:12:17
+   |
+LL |         pub use self::d::*;
+   |                 ^^^^^^^^^^
+   = help: consider adding an explicit import of `E` to disambiguate
+   = note: `#[warn(ambiguous_glob_imports)]` on by default
+
+error: aborting due to 1 previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0432`.