Add extra-files to opam files

src/lib/packages.ml

@@ -83,6 +83,28 @@ let mandatory_fields case ?seed opam =
   |> OpamFile.OPAM.with_descr_opt descr
   |> OpamFile.OPAM.with_dev_repo dev_repo
 
+let add_xfiles repo files opam =
+  let orig =
+    match OpamFile.OPAM.extra_files opam with
+    | None -> OpamFilename.Base.Map.empty
+    | Some xfiles ->
+      OpamFilename.Base.Map.of_list xfiles
+  in
+  let xfiles =
+    List.fold_left (fun map (file, nv) ->
+        let bfile =
+          OpamFilename.Base.of_string
+            (OpamFilename.remove_prefix
+               (OpamRepositoryPath.files repo None nv) file)
+        in
+        OpamFilename.Base.Map.add bfile
+          (OpamHash.compute (OpamFilename.to_string file))
+          map)
+      orig files
+  in
+  OpamFile.OPAM.with_extra_files
+    (OpamFilename.Base.Map.bindings xfiles)
+    opam
 
 let opam nv kind path seed =
   let opam = OpamFile.OPAM.create nv in
@@ -230,16 +252,20 @@ let write repo contents_root t =
     archive
   ];
   OpamFilename.rmdir files;
-  OpamFile.OPAM.write opam t.opam;
   write_opt (OpamFilename.write archive) t.archive;
   content_write contents_root t.nv t.contents;
-  if t.files <> [] then
-    (OpamFilename.mkdir files;
-     List.iter (fun (base, str, mode) ->
-         let file = OpamFilename.create files base in
-         OpamFilename.write file str;
-         OpamFilename.chmod file mode
-       ) t.files)
+  let opamfile =
+    if t.files <> [] then
+      (OpamFilename.mkdir files;
+       List.fold_left (fun opam (base, str, mode) ->
+           let file = OpamFilename.create files base in
+           OpamFilename.write file str;
+           OpamFilename.chmod file mode;
+           add_xfiles repo [file, t.nv] opam)
+         t.opam t.files)
+    else t.opam
+  in
+  OpamFile.OPAM.write opam opamfile
 
 let read_opt f file =
   if OpamFilename.exists file then Some (f file)