From 1b1c5f032d8325537a5b8abe14d8954e93013a57 Mon Sep 17 00:00:00 2001
From: Rudi Grinberg <rudi.grinberg@gmail.com>
Date: Mon, 2 Apr 2018 23:15:07 +0800
Subject: [PATCH 1/2] Test to show broken lazy loading of rules

---
 test/blackbox-tests/test-cases/odoc/jbuild | 5 +++++
 test/blackbox-tests/test-cases/odoc/run.t  | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/test/blackbox-tests/test-cases/odoc/jbuild b/test/blackbox-tests/test-cases/odoc/jbuild
index 79f74895..6e206671 100644
--- a/test/blackbox-tests/test-cases/odoc/jbuild
+++ b/test/blackbox-tests/test-cases/odoc/jbuild
@@ -16,3 +16,8 @@
  ((name runtest)
   (deps (_doc/_html/index.html))
   (action (echo "${read:_doc/_html/index.html}"))))
+
+(alias
+ ((name foo-mld)
+  (deps (_doc/_mlds/foo/index.mld))
+  (action (echo "${read:_doc/_mlds/foo/index.mld}"))))
diff --git a/test/blackbox-tests/test-cases/odoc/run.t b/test/blackbox-tests/test-cases/odoc/run.t
index c7077588..bc11aef2 100644
--- a/test/blackbox-tests/test-cases/odoc/run.t
+++ b/test/blackbox-tests/test-cases/odoc/run.t
@@ -31,3 +31,7 @@
       </div>
     </body>
   </html>
+
+  $ $JBUILDER build @foo-mld -j1 --display short --root .
+  No rule found for _doc/_mlds/foo/index.mld
+  [1]

From ff211b18a7fe2358380770c93613e075d53d0ef5 Mon Sep 17 00:00:00 2001
From: Rudi Grinberg <rudi.grinberg@gmail.com>
Date: Mon, 2 Apr 2018 23:15:56 +0800
Subject: [PATCH 2/2] Fix lazy loading of rules

We must load package rules when a file in the _mld dir is requested
---
 src/odoc.ml                               | 24 ++++++++++++-----------
 test/blackbox-tests/test-cases/odoc/run.t |  6 ++++--
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/src/odoc.ml b/src/odoc.ml
index 9096a338..08f95004 100644
--- a/src/odoc.ml
+++ b/src/odoc.ml
@@ -501,17 +501,19 @@ module Gen (S : sig val sctx : SC.t end) = struct
     in
     SC.packages sctx
     |> Package.Name.Map.iter ~f:(fun (pkg : Package.t) ->
-      SC.on_load_dir sctx
-        ~dir:(Paths.odocs (Pkg pkg.name))
-        ~f:(fun () ->
-          setup_package_odoc_rules
-            ~pkg
-            ~mlds:(
-              docs_by_package pkg
-              |> List.concat_map ~f:(fun (dir, doc) -> mlds_of_dir doc ~dir)
-            )
-            ~entry_modules_by_lib:modules_by_lib
-        );
+      let rules = lazy (
+        setup_package_odoc_rules
+          ~pkg
+          ~mlds:(
+            docs_by_package pkg
+            |> List.concat_map ~f:(fun (dir, doc) -> mlds_of_dir doc ~dir)
+          )
+          ~entry_modules_by_lib:modules_by_lib
+      ) in
+      List.iter [ Paths.odocs (Pkg pkg.name)
+                ; Paths.gen_mld_dir pkg ]
+        ~f:(fun dir ->
+          SC.on_load_dir sctx ~dir ~f:(fun () -> Lazy.force rules));
       (* setup @doc to build the correct html for the package *)
       setup_package_aliases pkg;
     );
diff --git a/test/blackbox-tests/test-cases/odoc/run.t b/test/blackbox-tests/test-cases/odoc/run.t
index bc11aef2..ef7ee3f0 100644
--- a/test/blackbox-tests/test-cases/odoc/run.t
+++ b/test/blackbox-tests/test-cases/odoc/run.t
@@ -33,5 +33,7 @@
   </html>
 
   $ $JBUILDER build @foo-mld -j1 --display short --root .
-  No rule found for _doc/_mlds/foo/index.mld
-  [1]
+  {1 Library foo}
+  This library exposes the following toplevel modules: {!modules:Foo}.
+  {1 Library foo.byte}
+  This library exposes the following toplevel modules: {!modules:Foo_byte}.