3 files changed, 74 insertions, 21 deletions

diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index a4b8d6683..279c06d65 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -863,7 +863,7 @@ pub trait TypeWalk {
             &mut |ty, binders| {
                 if let &mut Ty::Bound(bound) = ty {
                     if bound.debruijn >= binders {
-                        *ty = substs.0[bound.index].clone();
+                        *ty = substs.0[bound.index].clone().shift_bound_vars(binders);
                     }
                 }
             },
diff --git a/crates/ra_hir_ty/src/tests.rs b/crates/ra_hir_ty/src/tests.rs
index 81fc0f63a..846005baa 100644
--- a/crates/ra_hir_ty/src/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -18,16 +18,19 @@ use hir_def::{
     nameres::CrateDefMap,
     AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId,
 };
-use hir_expand::InFile;
+use hir_expand::{db::AstDatabase, InFile};
 use insta::assert_snapshot;
 use ra_db::{fixture::WithFixture, salsa::Database, FilePosition, SourceDatabase};
 use ra_syntax::{
     algo,
     ast::{self, AstNode},
+    SyntaxNode,
 };
 use stdx::format_to;
 
-use crate::{db::HirDatabase, display::HirDisplay, test_db::TestDB, InferenceResult};
+use crate::{
+    db::HirDatabase, display::HirDisplay, infer::TypeMismatch, test_db::TestDB, InferenceResult, Ty,
+};
 
 // These tests compare the inference results for all expressions in a file
 // against snapshots of the expected results using insta. Use cargo-insta to
@@ -67,13 +70,19 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
 
     let mut infer_def = |inference_result: Arc<InferenceResult>,
                          body_source_map: Arc<BodySourceMap>| {
-        let mut types = Vec::new();
-        let mut mismatches = Vec::new();
+        let mut types: Vec<(InFile<SyntaxNode>, &Ty)> = Vec::new();
+        let mut mismatches: Vec<(InFile<SyntaxNode>, &TypeMismatch)> = Vec::new();
 
         for (pat, ty) in inference_result.type_of_pat.iter() {
             let syntax_ptr = match body_source_map.pat_syntax(pat) {
                 Ok(sp) => {
-                    sp.map(|ast| ast.either(|it| it.syntax_node_ptr(), |it| it.syntax_node_ptr()))
+                    let root = db.parse_or_expand(sp.file_id).unwrap();
+                    sp.map(|ptr| {
+                        ptr.either(
+                            |it| it.to_node(&root).syntax().clone(),
+                            |it| it.to_node(&root).syntax().clone(),
+                        )
+                    })
                 }
                 Err(SyntheticSyntax) => continue,
             };
@@ -81,29 +90,31 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
         }
 
         for (expr, ty) in inference_result.type_of_expr.iter() {
-            let syntax_ptr = match body_source_map.expr_syntax(expr) {
-                Ok(sp) => sp.map(|ast| ast.syntax_node_ptr()),
+            let node = match body_source_map.expr_syntax(expr) {
+                Ok(sp) => {
+                    let root = db.parse_or_expand(sp.file_id).unwrap();
+                    sp.map(|ptr| ptr.to_node(&root).syntax().clone())
+                }
                 Err(SyntheticSyntax) => continue,
             };
-            types.push((syntax_ptr.clone(), ty));
+            types.push((node.clone(), ty));
             if let Some(mismatch) = inference_result.type_mismatch_for_expr(expr) {
-                mismatches.push((syntax_ptr, mismatch));
+                mismatches.push((node, mismatch));
             }
         }
 
         // sort ranges for consistency
-        types.sort_by_key(|(src_ptr, _)| {
-            (src_ptr.value.range().start(), src_ptr.value.range().end())
+        types.sort_by_key(|(node, _)| {
+            let range = node.value.text_range();
+            (range.start(), range.end())
         });
-        for (src_ptr, ty) in &types {
-            let node = src_ptr.value.to_node(&src_ptr.file_syntax(&db));
-
-            let (range, text) = if let Some(self_param) = ast::SelfParam::cast(node.clone()) {
+        for (node, ty) in &types {
+            let (range, text) = if let Some(self_param) = ast::SelfParam::cast(node.value.clone()) {
                 (self_param.self_token().unwrap().text_range(), "self".to_string())
             } else {
-                (src_ptr.value.range(), node.text().to_string().replace("\n", " "))
+                (node.value.text_range(), node.value.text().to_string().replace("\n", " "))
             };
-            let macro_prefix = if src_ptr.file_id != file_id.into() { "!" } else { "" };
+            let macro_prefix = if node.file_id != file_id.into() { "!" } else { "" };
             format_to!(
                 buf,
                 "{}{} '{}': {}\n",
@@ -114,11 +125,12 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
             );
         }
         if include_mismatches {
-            mismatches.sort_by_key(|(src_ptr, _)| {
-                (src_ptr.value.range().start(), src_ptr.value.range().end())
+            mismatches.sort_by_key(|(node, _)| {
+                let range = node.value.text_range();
+                (range.start(), range.end())
             });
             for (src_ptr, mismatch) in &mismatches {
-                let range = src_ptr.value.range();
+                let range = src_ptr.value.text_range();
                 let macro_prefix = if src_ptr.file_id != file_id.into() { "!" } else { "" };
                 format_to!(
                     buf,
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
index 61284d672..61a6801fc 100644
--- a/crates/ra_hir_ty/src/tests/regression.rs
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -533,3 +533,44 @@ fn foo(b: Bar) {
     "###
     );
 }
+
+#[test]
+fn issue_4053_diesel_where_clauses() {
+    assert_snapshot!(
+        infer(r#"
+trait BoxedDsl<DB> {
+    type Output;
+    fn internal_into_boxed(self) -> Self::Output;
+}
+
+struct SelectStatement<From, Select, Distinct, Where, Order, LimitOffset, GroupBy, Locking> {
+    order: Order,
+}
+
+trait QueryFragment<DB: Backend> {}
+
+trait Into<T> { fn into(self) -> T; }
+
+impl<F, S, D, W, O, LOf, DB> BoxedDsl<DB>
+    for SelectStatement<F, S, D, W, O, LOf, G>
+where
+    O: Into<dyn QueryFragment<DB>>,
+{
+    type Output = XXX;
+
+    fn internal_into_boxed(self) -> Self::Output {
+        self.order.into();
+    }
+}
+"#),
+        @r###"
+    [66; 70) 'self': Self
+    [268; 272) 'self': Self
+    [467; 471) 'self': SelectStatement<F, S, D, W, O, LOf, {unknown}, {unknown}>
+    [489; 523) '{     ...     }': ()
+    [499; 503) 'self': SelectStatement<F, S, D, W, O, LOf, {unknown}, {unknown}>
+    [499; 509) 'self.order': O
+    [499; 516) 'self.o...into()': dyn QueryFragment<DB>
+    "###
+    );
+}