Fix dune exec -- wrt file path, public_name with or without .exe

Fix for ocaml#3322 "dune exec needs to add .exe on Windows".

Signed-off-by: Antonin Décimo <antonin@tarides.com>

Author: MisterDA

bin/exec.ml

@@ -26,7 +26,7 @@ let man =
   ; Common.examples
       [ ("Run the executable named `my_exec'", "dune exec my_exec")
       ; ( "Run the executable defined in `foo.ml' with the argument `arg'"
-        , "dune exec ./foo.exe -- arg" )
+        , "dune exec -- ./foo.exe arg" )
       ]
   ]
 
@@ -66,11 +66,13 @@ let term =
             let open Memo.Build.O in
             (match prog_where with
             | `Search p ->
-              [ Path.Build.relative
+              let p =
+                Path.Build.relative
                   (Local_install_path.bin_dir ~context:context.name)
                   p
                 |> Path.build
-              ]
+              in
+              [ p; Path.extend_basename p ~suffix:Bin.exe ]
             | `This_rel p when Sys.win32 ->
               [ p; Path.extend_basename p ~suffix:Bin.exe ]
             | `This_rel p -> [ p ]

test/blackbox-tests/test-cases/public_name-exe.t/dune

@@ -0,0 +1,3 @@
+(executable
+ (name example)
+ (public_name shaihulud))

test/blackbox-tests/test-cases/public_name-exe.t/dune-project

@@ -0,0 +1,8 @@
+(lang dune 2.8)
+(generate_opam_files true)
+(package
+ (name mypackage)
+ (synopsis "My first Dune package!")
+ (description "\| This is my first attempt at creating
+              "\| a project with Dune.
+))

test/blackbox-tests/test-cases/public_name-exe.t/example.ml

@@ -0,0 +1 @@
+let () = print_endline "Hello, World!"

test/blackbox-tests/test-cases/public_name-exe.t/mypackage.opam

@@ -0,0 +1,25 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis: "My first Dune package!"
+description: """
+This is my first attempt at creating
+a project with Dune.
+"""
+depends: [
+  "dune" {>= "2.8"}
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]

test/blackbox-tests/test-cases/public_name-exe.t/run.t

@@ -0,0 +1,88 @@
+Test case for https://github.com/ocaml/dune/issues/3322
+"dune exec needs to add .exe on Windows"
+
+  $ os_type=$(ocamlc -config-var os_type)
+
+Test that on Windows `dune exec -- public_name` and
+`dune exec -- public_name.exe` have the same effect.
+
+With extension
+==============
+
+  $ dune clean
+  $ dune build @install
+  $ if [ $os_type = Win32 ]; then dune exec -- shaihulud.exe; else echo "Hello, World!"; fi
+  Hello, World!
+
+Without extension, prebuild
+=================
+
+  $ dune clean
+  $ dune build @install
+  $ dune exec -- shaihulud
+  Hello, World!
+
+
+Test that `dune exec -- public_name` (omitting the .exe) works from a
+clean state.
+
+Without extension, clean state
+==============================
+
+  $ dune clean
+  $ dune exec -- shaihulud
+  Hello, World!
+
+
+Test that the public name resolves well to the actual executable file
+when a dependency changes. On platforms where there are no symlinks,
+updating the public_name executable matters.
+
+With extension, prebuild
+==============
+
+  $ dune clean
+  $ dune build @install
+
+  $ if [ $os_type = Win32 ]; then dune exec -- shaihulud.exe; else echo "Hello, World!"; fi
+  Hello, World!
+  $ dune exec -- ./example.exe
+  Hello, World!
+  $ sed -i'' 's/World/Arrakis/' example.ml
+  $ if [ $os_type = Win32 ]; then dune exec -- shaihulud.exe; else echo "Hello, Arrakis!"; fi
+  Hello, Arrakis!
+  $ dune exec -- ./example.exe
+  Hello, Arrakis!
+
+Without extension, prebuild
+=================
+
+  $ sed -i'' 's/Arrakis/World/' example.ml
+  $ dune clean
+  $ dune build @install
+
+  $ dune exec -- shaihulud
+  Hello, World!
+  $ dune exec -- ./example.exe
+  Hello, World!
+  $ sed -i'' 's/World/Arrakis/' example.ml
+  $ dune exec -- shaihulud
+  Hello, Arrakis!
+  $ dune exec -- ./example.exe
+  Hello, Arrakis!
+
+Without extention, clean state
+==============================
+
+  $ sed -i'' 's/Arrakis/World/' example.ml
+  $ dune clean
+
+  $ dune exec -- shaihulud
+  Hello, World!
+  $ dune exec -- ./example.exe
+  Hello, World!
+  $ sed -i'' 's/World/Arrakis/' example.ml
+  $ dune exec -- shaihulud
+  Hello, Arrakis!
+  $ dune exec -- ./example.exe
+  Hello, Arrakis!