5 files changed, 31 insertions, 5 deletions

diff --git a/crates/ra_hir_ty/src/db.rs b/crates/ra_hir_ty/src/db.rs
index d52f65b83..eb521c7a0 100644
--- a/crates/ra_hir_ty/src/db.rs
+++ b/crates/ra_hir_ty/src/db.rs
@@ -7,6 +7,7 @@ use hir_def::{
 };
 use ra_arena::map::ArenaMap;
 use ra_db::{salsa, CrateId};
+use ra_prof::profile;
 
 use crate::{
     method_resolution::CrateImplBlocks,
@@ -18,9 +19,12 @@ use crate::{
 #[salsa::query_group(HirDatabaseStorage)]
 #[salsa::requires(salsa::Database)]
 pub trait HirDatabase: DefDatabase {
-    #[salsa::invoke(crate::infer_query)]
+    #[salsa::transparent]
     fn infer(&self, def: DefWithBodyId) -> Arc<InferenceResult>;
 
+    #[salsa::invoke(crate::do_infer_query)]
+    fn do_infer(&self, def: DefWithBodyId) -> Arc<InferenceResult>;
+
     #[salsa::invoke(crate::lower::ty_query)]
     #[salsa::cycle(crate::lower::ty_recover)]
     fn ty(&self, def: TyDefId) -> Ty;
@@ -104,6 +108,11 @@ pub trait HirDatabase: DefDatabase {
     ) -> Option<crate::traits::Solution>;
 }
 
+fn infer(db: &impl HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {
+    let _p = profile("infer");
+    db.do_infer(def)
+}
+
 #[test]
 fn hir_database_is_object_safe() {
     fn _assert_object_safe(_: &dyn HirDatabase) {}
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index 37e69599d..e2eda3134 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -62,8 +62,8 @@ mod pat;
 mod coerce;
 
 /// The entry point of type inference.
-pub fn infer_query(db: &impl HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {
-    let _p = profile("infer_query");
+pub fn do_infer_query(db: &impl HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {
+    let _p = profile("do_infer");
     let resolver = def.resolver(db);
     let mut ctx = InferenceContext::new(db, def, resolver);
 
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index 55b6dd836..d63f862dc 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -58,7 +58,7 @@ use crate::{
 use display::{HirDisplay, HirFormatter};
 
 pub use autoderef::autoderef;
-pub use infer::{infer_query, InferTy, InferenceResult};
+pub use infer::{do_infer_query, InferTy, InferenceResult};
 pub use lower::CallableDef;
 pub use lower::{callable_item_sig, TyDefId, ValueTyDefId};
 pub use traits::{InEnvironment, Obligation, ProjectionPredicate, TraitEnvironment};
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index af3db2e1d..2c2ecee9c 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -331,7 +331,7 @@ pub(super) fn substs_from_path_segment(
     if let Some(generic_args) = &segment.args_and_bindings {
         // if args are provided, it should be all of them, but we can't rely on that
         let self_param_correction = if add_self_param { 1 } else { 0 };
-        let child_len = child_len + self_param_correction;
+        let child_len = child_len - self_param_correction;
         for arg in generic_args.args.iter().take(child_len) {
             match arg {
                 GenericArg::Type(type_ref) => {
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
index 8b3aa8564..13c5f62e4 100644
--- a/crates/ra_hir_ty/src/tests/regression.rs
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -365,3 +365,20 @@ fn issue_2669() {
     "###
     )
 }
+
+#[test]
+fn issue_2705() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {}
+fn test() {
+    <Trait<u32>>::foo()
+}
+"#),
+        @r###"
+    [26; 53) '{     ...oo() }': ()
+    [32; 49) '<Trait...>::foo': {unknown}
+    [32; 51) '<Trait...:foo()': ()
+    "###
+    );
+}