From afa7173d93f71979ee5b876a4a7e137c1491d379 Mon Sep 17 00:00:00 2001
From: Leo White <leo@lpw25.net>
Date: Fri, 30 Nov 2018 10:02:33 +0000
Subject: [PATCH 1/2] Apply substitution to all modules when packing

---
 typing/typemod.ml | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/typing/typemod.ml b/typing/typemod.ml
index af93876cc..1162d982a 100644
--- a/typing/typemod.ml
+++ b/typing/typemod.ml
@@ -2484,18 +2484,31 @@ let type_interface sourcefile env ast =
 (* "Packaging" of several compilation units into one unit
    having them as sub-modules.  *)
 
-let rec package_signatures subst = function
-    [] -> []
-  | (name, sg) :: rem ->
-      let sg' = Subst.signature subst sg in
-      let oldid = Ident.create_persistent name
-      and newid = Ident.create_local name in
-      Sig_module(newid, Mp_present, {md_type=Mty_signature sg';
-                         md_attributes=[];
-                         md_loc=Location.none;
-                        },
-                 Trec_not, Exported) ::
-      package_signatures (Subst.add_module oldid (Pident newid) subst) rem
+let package_signatures units =
+  let units_with_ids =
+    List.map
+      (fun (name, sg) ->
+        let oldid = Ident.create_persistent name in
+        let newid = Ident.create_local name in
+        (oldid, newid, sg))
+      units
+  in
+  let subst =
+    List.fold_left
+      (fun acc (oldid, newid, _) ->
+        Subst.add_module oldid (Pident newid) acc)
+      Subst.identity units_with_ids
+  in
+  List.map
+    (fun (_, newid, sg) ->
+      let sg = Subst.signature subst sg in
+      let md =
+        { md_type=Mty_signature sg;
+          md_attributes=[];
+          md_loc=Location.none; }
+      in
+      Sig_module(newid, Mp_present, md, Trec_not, Exported))
+    units_with_ids
 
 let package_units initial_env objfiles cmifile modulename =
   (* Read the signatures of the units *)
@@ -2513,7 +2526,7 @@ let package_units initial_env objfiles cmifile modulename =
       objfiles in
   (* Compute signature of packaged unit *)
   Ident.reinit();
-  let sg = package_signatures Subst.identity units in
+  let sg = package_signatures units in
   (* See if explicit interface is provided *)
   let prefix = Filename.remove_extension cmifile in
   let mlifile = prefix ^ !Config.interface_suffix in

From f0cd88623ee7893cfbce81e0771c30d8c0abbe71 Mon Sep 17 00:00:00 2001
From: Leo White <leo@lpw25.net>
Date: Sat, 1 Dec 2018 16:20:41 +0000
Subject: [PATCH 2/2] Add Changes entry

---
 Changes | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Changes b/Changes
index 553316b97..0af0bd53a 100644
--- a/Changes
+++ b/Changes
@@ -703,6 +703,8 @@ Working version
 - GPR#2131: fix wrong calls to Env.normalize_path on non-module paths
   (Alain Frisch, review by Jacques Garrigue)
 
+- GPR#2175: Apply substitution to all modules when packing
+  (Leo White, review by Gabriel Scherer)
 
 OCaml 4.07.1 (4 October 2018)
 -----------------------------