repository: fix OPAMFETCH/OPAMCURL handling

OPAMCURL is ignored if OPAMFETCH is set. This is changed to handle
OPAMCURL specification when OPAMFETCH is set to "curl" (simple command,
or new arguments). If OPAMFETCH is set to another tool, OPAMCURL is
ignored.

src/repository/opamRepositoryConfig.ml

@@ -122,13 +122,19 @@ let initk k =
               (CString cmd, None), `Default
           in
           let c = cmd :: List.map (fun a -> OpamTypes.CString a, None) a in
-          Some (lazy (c, kind))
+          Some (c, kind)
         | [] ->
           None
       )
-    >>+ fun () ->
-    E.curl () >>| (fun s ->
-        lazy ([CString s, None], `Curl))
+    |> (fun fetch ->
+        match E.curl (), fetch with
+        | None, fetch -> OpamStd.Option.map Lazy.from_val fetch
+        | Some cmd, Some (((CIdent "curl"| CString "curl"), filter)::args, _) ->
+          Some (lazy ((CString cmd, filter)::args, `Curl))
+        | Some cmd, None ->
+          Some (lazy ([CString cmd, None], `Curl))
+        | Some _, _ -> (* ignored *)
+          OpamStd.Option.map Lazy.from_val fetch)
   in
   let validation_hook =
     E.validationhook () >>| fun s ->

tests/reftests/download.test

@@ -88,9 +88,9 @@ The following actions will be performed:
 <><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
 Processing  1/1: [foo.1: http]
 curl "--another-args" "3"
-[ERROR] Failed to get sources of foo.1: Curl failed
+[ERROR] Failed to get sources of foo.1: curl error code ***The curl is a lie*** [args: --another-args 3]
 
-OpamSolution.Fetch_fail("https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz (Curl failed: curl --another-args 3\" exited with code 2)")
+OpamSolution.Fetch_fail("https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz (curl: code ***The curl is a lie*** [args: --another-args 3] while downloading https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz)")
 
 
 <><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
@@ -100,17 +100,22 @@ OpamSolution.Fetch_fail("https://github.com/UnixJunkie/get_line/archive/v1.0.0.t
 Clearing cache of downloaded files
 ### :I:e: FETCH curl & local curl
 ### OPAMFETCH=curl OPAMCURL=$BASEDIR/bin/curl
-### opam install foo --download-only | grep -v "^+-" | sed-cmd curl | sed-cmd tar | "${OPAMVERSION}" -> "current"
+### opam install foo --download-only | grep -v "^+-" | sed-cmd curl
 The following actions will be performed:
 === install 1 package
   - install foo 1
 
 <><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
 Processing  1/1: [foo.1: http]
-curl "--write-out" "%{http_code}\n" "--retry" "3" "--retry-delay" "2" "--user-agent" "opam/current" "-L" "-o" "${BASEDIR}/OPAM/download/.opam-switch/sources/foo.1/v1.0.0.tar.gz.part" "--" "https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz"
-Processing  1/1:
-tar "xfz" "${OPAMTMP}/v1.0.0.tar.gz" "-C" "${OPAMTMP}"
-Done.
+curl "--write-out" "%{http_code}\n" "--retry" "3" "--retry-delay" "2" "--user-agent" "opam/2.2.0~alpha" "-L" "-o" "${BASEDIR}/OPAM/download/.opam-switch/sources/foo.1/v1.0.0.tar.gz.part" "--" "https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz"
+[ERROR] Failed to get sources of foo.1: curl error code ***The curl is a lie*** [args: --write-out %{http_code}\n --retry 3 --retry-delay 2 --user-agent opam/2.2.0~alpha -L -o ${BASEDIR}/OPAM/download/.opam-switch/sources/foo.1/v1.0.0.tar.gz.part -- https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz]
+
+OpamSolution.Fetch_fail("https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz (curl: code ***The curl is a lie*** [args: --write-out %{http_code}\n --retry 3 --retry-delay 2 --user-agent opam/2.2.0~alpha -L -o ${BASEDIR}/OPAM/download/.opam-switch/sources/foo.1/v1.0.0.tar.gz.part -- https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz] while downloading https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz)")
+
+
+<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
+'${OPAM} install foo --download-only' failed.
+# Return code 40 #
 ### opam clean -c
 Clearing cache of downloaded files
 ### :I:f: FETCH curl with args & local curl
@@ -123,9 +128,9 @@ The following actions will be performed:
 <><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
 Processing  1/1: [foo.1: http]
 curl "--another-args" "3"
-[ERROR] Failed to get sources of foo.1: Curl failed
+[ERROR] Failed to get sources of foo.1: curl error code ***The curl is a lie*** [args: --another-args 3]
 
-OpamSolution.Fetch_fail("https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz (Curl failed: curl --another-args 3\" exited with code 2)")
+OpamSolution.Fetch_fail("https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz (curl: code ***The curl is a lie*** [args: --another-args 3] while downloading https://github.com/UnixJunkie/get_line/archive/v1.0.0.tar.gz)")
 
 
 <><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>