Two fixes for working with heritages

askama_derive/src/lib.rs

@@ -65,7 +65,7 @@ fn build_template(ast: &syn::DeriveInput) -> Result<String, CompileError> {
         eprintln!("{:?}", parsed[&input.path]);
     }
 
-    let code = generator::generate(&input, &contexts, &heritage, INTEGRATIONS)?;
+    let code = generator::generate(&input, &contexts, heritage.as_ref(), INTEGRATIONS)?;
     if input.print == Print::Code || input.print == Print::All {
         eprintln!("{}", code);
     }

askama_shared/src/generator.rs

@@ -15,7 +15,7 @@ use std::{cmp, hash, mem, str};
 pub fn generate<S: std::hash::BuildHasher>(
     input: &TemplateInput<'_>,
     contexts: &HashMap<&PathBuf, Context<'_>, S>,
-    heritage: &Option<Heritage<'_>>,
+    heritage: Option<&Heritage<'_>>,
     integrations: Integrations,
 ) -> Result<String, CompileError> {
     Generator::new(input, contexts, heritage, integrations, MapChain::new())
@@ -28,7 +28,7 @@ struct Generator<'a, S: std::hash::BuildHasher> {
     // All contexts, keyed by the package-relative template path
     contexts: &'a HashMap<&'a PathBuf, Context<'a>, S>,
     // The heritage contains references to blocks and their ancestry
-    heritage: &'a Option<Heritage<'a>>,
+    heritage: Option<&'a Heritage<'a>>,
     // What integrations need to be generated
     integrations: Integrations,
     // Variables accessible directly from the current scope (not redirected to context)
@@ -52,7 +52,7 @@ impl<'a, S: std::hash::BuildHasher> Generator<'a, S> {
     fn new<'n>(
         input: &'n TemplateInput<'_>,
         contexts: &'n HashMap<&'n PathBuf, Context<'n>, S>,
-        heritage: &'n Option<Heritage<'_>>,
+        heritage: Option<&'n Heritage<'_>>,
         integrations: Integrations,
         locals: MapChain<'n, &'n str, LocalMeta>,
     ) -> Generator<'n, S> {

askama_shared/src/heritage.rs

@@ -10,9 +10,9 @@ pub struct Heritage<'a> {
 }
 
 impl Heritage<'_> {
-    pub fn new<'n>(
+    pub fn new<'n, S: std::hash::BuildHasher>(
         mut ctx: &'n Context<'n>,
-        contexts: &'n HashMap<&'n PathBuf, Context<'n>>,
+        contexts: &'n HashMap<&'n PathBuf, Context<'n>, S>,
     ) -> Heritage<'n> {
         let mut blocks: BlockAncestry<'n> = ctx
             .blocks