Fix false "no cmi" reporting from errors command (#1577)

 from voodoos/fix-errors-false-no-cmi-reporting

Author: voodoos

CHANGES.md

@@ -17,6 +17,8 @@ unreleased
     - Fix object method completion not working (#1606, fixes #1575)
     - Improve context detection for package types (#1608, fixes #1607)
     - Fix incorrect locations for string literals (#1574)
+    - Fixed an issue that caused `errors` to erroneously alert about missing
+      `cmi` files (#1577)
   + editor modes
     - emacs: call the user's configured completion UI in
       `merlin-construct` (#1598)

src/frontend/query_commands.ml

@@ -656,10 +656,10 @@ let dispatch pipeline (type a) : a Query_protocol.t -> a =
   | Errors { lexing; parsing; typing }->
     let typer = Mpipeline.typer_result pipeline in
     let verbosity = verbosity pipeline in
-    Printtyp.wrap_printing_env (Mtyper.get_env typer) ~verbosity @@ fun () ->
     let lexer_errors  = Mpipeline.reader_lexer_errors pipeline  in
     let parser_errors = Mpipeline.reader_parser_errors pipeline in
     let typer_errors  = Mpipeline.typer_errors pipeline  in
+    Printtyp.wrap_printing_env (Mtyper.get_env typer) ~verbosity @@ fun () ->
     (* When there is a cmi error, we will have a lot of meaningless errors,
        there is no need to report them. *)
     let typer_errors =

tests/test-dirs/errors/no-cmi.t

@@ -0,0 +1,29 @@
+  $ mkdir liba
+  $ cat >liba/liba.ml <<EOF
+  > module Libb = Libb
+  > EOF
+
+  $ mkdir libb
+  $ cat >libb/libb.ml <<EOF
+  > let x = 42
+  > EOF
+
+  $ cat >liba/.merlin <<EOF
+  > B .
+  > B ../libb
+  > EOF
+
+  $ (cd libb && $OCAMLC -c -bin-annot libb.ml)
+  $ (cd liba && $OCAMLC -c -bin-annot liba.ml -I ../libb)
+
+
+  $ ls libb
+  libb.cmi
+  libb.cmo
+  libb.cmt
+  libb.ml
+
+There should be no errors
+  $ cd liba && $MERLIN single errors -filename liba.ml<liba.ml |
+  > jq '.value'
+  []