Fix import bug

2 files changed, 12 insertions, 15 deletions

diff --git a/dhall/build.rs b/dhall/build.rs
index ec31192..784ce93 100644
--- a/dhall/build.rs
+++ b/dhall/build.rs
@@ -330,12 +330,7 @@ fn generate_tests() -> std::io::Result<()> {
             module_name: "type_inference_success",
             directory: "type-inference/success/",
             variant: "TypeInferenceSuccess",
-            exclude_path: Rc::new(|path: &str| {
-                false
-                    // Too slow, but also not all features implemented
-                    // For now needs support for hashed imports
-                    || path == "prelude"
-            }),
+            too_slow_path: Rc::new(|path: &str| path == "prelude"),
             output_type: Some(FileType::Text),
             ..default_feature.clone()
         },
diff --git a/dhall/src/semantics/resolve/env.rs b/dhall/src/semantics/resolve/env.rs
index d7ff0ae..6346a6d 100644
--- a/dhall/src/semantics/resolve/env.rs
+++ b/dhall/src/semantics/resolve/env.rs
@@ -71,7 +71,7 @@ impl ImportEnv {
 
     pub fn handle_import(
         &mut self,
-        location: ImportLocation,
+        mut location: ImportLocation,
         do_resolve: impl FnOnce(&mut Self) -> Result<TypedHir, Error>,
     ) -> Result<TypedHir, Error> {
         if self.stack.contains(&location) {
@@ -82,14 +82,16 @@ impl ImportEnv {
         Ok(match self.cache.get(&location) {
             Some(expr) => expr.clone(),
             None => {
-                // Push the current location on the stack
-                self.stack.push(location);
-
-                // Resolve the import recursively
-                let expr = do_resolve(self)?;
-
-                // Remove location from the stack.
-                let location = self.stack.pop().unwrap();
+                let expr = {
+                    // Push the current location on the stack
+                    self.stack.push(location);
+                    // Resolve the import recursively
+                    // WARNING: do not propagate errors here or the stack will get messed up.
+                    let result = do_resolve(self);
+                    // Remove location from the stack.
+                    location = self.stack.pop().unwrap();
+                    result
+                }?;
 
                 // Add the resolved import to the cache
                 self.cache.insert(location, expr.clone());