Redirect opam on Windows if path contains a space.

It is needed for Cygwin installation, that doesn't handle paths with
space.
At init, detection and redirection are done, afterwards opam always load
redirected opam root.
Original root directory is stored in
`OpamStateConfig.!r.original_root_dir`.

master_changes.md

@@ -28,6 +28,7 @@ users)
   * Skip Git-for-Windows menu if the Git binary resolved in PATH is Git-for-Windows [#5963 @dra27 - fix #5835]
   * Enhance the Git menu by warning if the user appears to need to restart the shell to pick up PATH changes [#5963 @dra27]
   * Include Git for Windows installations in the list of possibilities where the user instructed Git-for-Windows setup not to update PATH [#5963 @dra27]
+  * Redirect the opam root to C:\opamroot when the opam root contains spaces on Windows [#5457 @rjbou]
 
 ## Config report
 

src/client/opamClient.ml

@@ -1235,7 +1235,42 @@ let init
     shell =
   log "INIT %a"
     (slog @@ OpamStd.Option.to_string OpamRepositoryBackend.to_string) repo;
-  let root = OpamStateConfig.(!r.root_dir) in
+  let root =
+    let root = OpamStateConfig.(!r.root_dir) in
+    let has_space s = OpamStd.String.contains_char s ' ' in
+    if Sys.win32 &&
+       has_space (OpamFilename.Dir.to_string root) then
+      (let default = "C:\\opamroot" in
+       let rec ask () =
+         match OpamConsole.read "Opam root: " with
+         | Some r ->
+           if has_space r then
+             (OpamConsole.msg
+                "Given path '%s' contains space, please choose another one.\n"
+                (OpamConsole.colorise `bold r);
+              ask ())
+           else r
+         | None -> default
+       in
+       let new_root_f =
+         if OpamConsole.confirm ~default:false
+             "Your opam root path '%s' contains a space, we'll redirect to \
+              '%s'.\nDo you want to choose and enter another spaceless folder?"
+             (OpamFilename.Dir.to_string root) default then
+           ask ()
+         else default
+       in
+       let new_root = OpamFilename.Dir.of_string new_root_f in
+       OpamFilename.write (OpamPath.redirected root) new_root_f;
+       (* Add the readme file in C:\opamroot as redirected *)
+       OpamFilename.write
+         OpamFilename.Op.(root // "readme.txt")
+         (Printf.sprintf "Opam root redirected from %s"
+            (OpamFilename.Dir.to_string OpamStateConfig.(!r.root_dir)));
+       OpamStateConfig.update ~root_dir:new_root ();
+       new_root)
+    else root
+  in
   let config_f = OpamPath.config root in
   let root_empty =
     not (OpamFilename.exists_dir root) || OpamFilename.dir_is_empty root in

src/client/opamClientConfig.ml

@@ -210,6 +210,15 @@ let opam_init ?root_dir ?strict ?solver =
 
   (* (i) get root dir *)
   let root = OpamStateConfig.opamroot ?root_dir () in
+  if Sys.win32
+     (* if default, redirection will be handled by opam init, or should have
+        been handled *)
+     && (root_dir <> None || OpamStateConfig.E.root () <> None)
+     && OpamStd.String.contains_char (OpamFilename.Dir.to_string root) ' ' then
+    OpamConsole.error "You opam root directory contains a space, this may lead \
+                       to several malfunction... bzzz.... nooo%s"
+      (* NOTE: UTF-8 Collision emoji *)
+      (if OpamConsole.color () then "\xF0\x9F\x92\xA5" else "");
 
   (* (ii) load conf file and set defaults *)
   (* the init for OpamFormat is done in advance since (a) it has an effect on

src/state/opamStateConfig.ml

@@ -70,23 +70,30 @@ type t = {
   no_depexts: bool;
 }
 
+let win_space_redirection root =
+  let redirected = OpamPath.redirected root in
+  if OpamFilename.exists redirected then
+    OpamFilename.Dir.of_string (OpamFilename.read redirected)
+  else root
+
+let default_root () =
+  (* On Windows, if a .opam directory is found in %HOME% or %USERPROFILE% then
+     then we'll use it. Otherwise, we use %LOCALAPPDATA%. *)
+  let home_location =
+    let open OpamFilename in
+    concat_and_resolve (Dir.of_string (OpamStd.Sys.home ())) ".opam"
+  in
+  if not Sys.win32 || OpamFilename.exists_dir home_location then
+    home_location
+  else
+  let open OpamFilename in
+  let local_appdata =
+    Dir.of_string (OpamStubs.getPathToLocalAppData ())
+  in
+  concat_and_resolve local_appdata "opam"
+
 let default = {
-  root_dir = (
-    (* On Windows, if a .opam directory is found in %HOME% or %USERPROFILE% then
-       then we'll use it. Otherwise, we use %LOCALAPPDATA%. *)
-    let home_location =
-      let open OpamFilename in
-      concat_and_resolve (Dir.of_string (OpamStd.Sys.home ())) ".opam"
-    in
-    if not Sys.win32 || OpamFilename.exists_dir home_location then
-      home_location
-    else
-      let open OpamFilename in
-      let local_appdata =
-        Dir.of_string (OpamStubs.getPathToLocalAppData ())
-      in
-      concat_and_resolve local_appdata "opam"
-    );
+  root_dir = default_root () |> win_space_redirection;
   original_root_dir = default_root ();
   current_switch = None;
   switch_from = `Default;
@@ -180,7 +187,9 @@ let initk k =
     | Some s -> Some (OpamSwitch.of_string s), Some `Env
   in
   setk (setk (fun c -> r := c; k)) !r
-    ?root_dir:(E.root () >>| OpamFilename.Dir.of_string)
+    ?root_dir:(E.root ()
+               >>| OpamFilename.Dir.of_string
+               >>| win_space_redirection)
     ?original_root_dir:(E.root () >>| OpamFilename.Dir.of_string)
     ?current_switch
     ?switch_from
@@ -208,6 +217,7 @@ let opamroot ?root_dir () =
   (root_dir >>+ fun () ->
    OpamStd.Env.getopt "OPAMROOT" >>| OpamFilename.Dir.of_string)
   +! default.root_dir
+  |> win_space_redirection
 
 let is_newer_raw = function
   | Some v ->

tests/reftests/env.test

@@ -439,60 +439,6 @@ The following actions will be performed:
 Done.
 ### opam exec -- sh -c "eval $(opam env | tr -d '\\r'); opam remove foo; opam env; eval $(opam env | tr -d '\\r'); opam env" | grep "FOO"
 FOO=''; export FOO;
-### : root and switch with spaces :
-### RT="$BASEDIR/root 2"
-### SW="switch w spaces"
-### OPAMNOENVNOTICE=0
-### opam init -na --bare --bypass-check --disable-sandbox --root "$RT" defaut ./REPO | grep -v Cygwin
-No configuration file found, using built-in defaults.
-
-<><> Fetching repository information ><><><><><><><><><><><><><><><><><><><><><>
-[defaut] Initialised
-### opam switch create "./$SW" nv --root "$RT"
-
-<><> Installing new switch packages <><><><><><><><><><><><><><><><><><><><><><>
-Switch invariant: ["nv"]
-
-<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
--> installed nv.1
-Done.
-# Run eval $(opam env '--root=${BASEDIR}/root 2' '--switch=${BASEDIR}/switch w spaces') to update the current shell environment
-### opam env --root "$RT" --switch "./$SW" | grep "NV_VARS" | ';' -> ':'
-NV_VARS3='foo:/yet/another/different/path': export NV_VARS3:
-NV_VARS4='': export NV_VARS4:
-NV_VARS_5925_1='foo': export NV_VARS_5925_1:
-NV_VARS_5925_2='foo': export NV_VARS_5925_2:
-NV_VARS_5925_3='foo': export NV_VARS_5925_3:
-NV_VARS_5925_4='foo': export NV_VARS_5925_4:
-NV_VARS_5925_5='foo:': export NV_VARS_5925_5:
-NV_VARS_5925_6='foo:': export NV_VARS_5925_6:
-NV_VARS_5925_7=':foo': export NV_VARS_5925_7:
-NV_VARS_5925_8=':foo': export NV_VARS_5925_8:
-NV_VARS_5926_L_1='b::a': export NV_VARS_5926_L_1:
-NV_VARS_5926_L_2='b::a': export NV_VARS_5926_L_2:
-NV_VARS_5926_L_3=':a:b': export NV_VARS_5926_L_3:
-NV_VARS_5926_L_4=':a:b': export NV_VARS_5926_L_4:
-NV_VARS_5926_L_5='b::a': export NV_VARS_5926_L_5:
-NV_VARS_5926_L_6='b::a': export NV_VARS_5926_L_6:
-NV_VARS_5926_L_7=':a:b': export NV_VARS_5926_L_7:
-NV_VARS_5926_L_8=':a:b': export NV_VARS_5926_L_8:
-NV_VARS_5926_M_1='b:a1::a2': export NV_VARS_5926_M_1:
-NV_VARS_5926_M_2='a1::a2:b': export NV_VARS_5926_M_2:
-NV_VARS_5926_M_3='b:a1::a2': export NV_VARS_5926_M_3:
-NV_VARS_5926_M_4='a1::a2:b': export NV_VARS_5926_M_4:
-NV_VARS_5926_S_1='a:': export NV_VARS_5926_S_1:
-NV_VARS_5926_S_2=':a': export NV_VARS_5926_S_2:
-NV_VARS_5926_S_3='a:': export NV_VARS_5926_S_3:
-NV_VARS_5926_S_4=':a': export NV_VARS_5926_S_4:
-NV_VARS_5926_T_1='b:a:': export NV_VARS_5926_T_1:
-NV_VARS_5926_T_2='b:a:': export NV_VARS_5926_T_2:
-NV_VARS_5926_T_3='a::b': export NV_VARS_5926_T_3:
-NV_VARS_5926_T_4='a::b': export NV_VARS_5926_T_4:
-NV_VARS_5926_T_5='b:a:': export NV_VARS_5926_T_5:
-NV_VARS_5926_T_6='b:a:': export NV_VARS_5926_T_6:
-NV_VARS_5926_T_7='a::b': export NV_VARS_5926_T_7:
-NV_VARS_5926_T_8='a::b': export NV_VARS_5926_T_8:
-### OPAMNOENVNOTICE=1
 ### : Env hooks :
 ### <pkg:av.1>
 opam-version: "2.0"

tests/reftests/env.unix.test

@@ -1,4 +1,30 @@
 N0REP0
+### : root and switches with spaces :
+### <pkg:nv.1>
+opam-version: "2.0"
+flags: compiler
+### RT="$BASEDIR/root 2"
+### SW="switch w spaces"
+### OPAMNOENVNOTICE=0
+### opam init -na --bare --bypass-check --disable-sandbox --root "$RT" defaut ./REPO
+No configuration file found, using built-in defaults.
+
+<><> Fetching repository information ><><><><><><><><><><><><><><><><><><><><><>
+[defaut] Initialised
+### opam switch create "./$SW" nv --root "$RT"
+
+<><> Installing new switch packages <><><><><><><><><><><><><><><><><><><><><><>
+Switch invariant: ["nv"]
+
+<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
+-> installed nv.1
+Done.
+# Run eval $(opam env '--root=${BASEDIR}/root 2' '--switch=${BASEDIR}/switch w spaces') to update the current shell environment
+### opam env --root "$RT" --switch "./$SW" | grep "PREFIX" | ';' -> ':'
+OPAM_SWITCH_PREFIX='${BASEDIR}/switch w spaces/_opam': export OPAM_SWITCH_PREFIX:
+### opam var root --root "$RT"
+${BASEDIR}/root 2
+### OPAMNOENVNOTICE=1
 ### : setenv & build env rewriting :
 ### opam switch create rewriting --empty
 ### ::::::::::::::::::

tests/reftests/init.win32.test

@@ -3,23 +3,26 @@ N0REP0
 ### rm -rf $OPAMROOT
 ### OPAMROOT="roots/with path"
 ### opam init --no-setup --bare --bypass-checks default REPO/ | grep -v Cygwin
+[ERROR] You opam root directory contains a space, this may lead to several malfunction... bzzz.... nooo
 No configuration file found, using built-in defaults.
+Your opam root path '${BASEDIR}/roots/with path' contains a space, we'll redirect to 'C:\opamroot'.
+Do you want to choose and enter another spaceless folder? [y/n] n
 
 <><> Fetching repository information ><><><><><><><><><><><><><><><><><><><><><>
 [default] Initialised
 ### opam var root --debug --debug-level=-1
 CLI                             Parsing CLI version 2.2
-GSTATE                          LOAD-GLOBAL-STATE @ ${BASEDIR}/roots/with path
-${BASEDIR}/roots/with path
+GSTATE                          LOAD-GLOBAL-STATE @ C:\opamroot
+C:\opamroot
 ### cat 'roots/with path/redirected-opamroot'
-/usr/bin/cat: 'roots/with path/redirected-opamroot': No such file or directory
-# Return code 1 #
+C:\opamroot
 ### opam switch create --empty test
 ### opam switch --debug --debug-level=-1
 CLI                             Parsing CLI version 2.2
-GSTATE                          LOAD-GLOBAL-STATE @ ${BASEDIR}/roots/with path
+GSTATE                          LOAD-GLOBAL-STATE @ C:\opamroot
 SWITCH                          list
 #   switch  compiler  description
 ->  test              test
 ### echo $OPAMROOT
 roots/with path
+### rm -rf 'C:\opamroot'