1 files changed, 33 insertions, 3 deletions
diff --git a/src/rebar_prv_shell.erl b/src/rebar_prv_shell.erl
index c644930..824293f 100644
--- a/src/rebar_prv_shell.erl
+++ b/src/rebar_prv_shell.erl
@@ -27,6 +27,7 @@
 
 -module(rebar_prv_shell).
 -author("Kresten Krab Thorup <krab@trifork.com>").
+-author("Fred Hebert <mononcqc@ferd.ca>").
 
 -behaviour(provider).
 
@@ -111,16 +112,44 @@ info() ->
     "Start a shell with project and deps preloaded similar to~n'erl -pa ebin -pa deps/*/ebin'.~n".
 
 setup_shell() ->
-    %% scan all processes for any with references to the old user and save them to
-    %% update later
+    OldUser = kill_old_user(),
+    %% Test for support here
+    NewUser = try erlang:open_port({spawn,'tty_sl -c -e'}, []) of
+        Port when is_port(Port) ->
+            true = port_close(Port),
+            setup_new_shell()
+    catch
+        error:_ ->
+            setup_old_shell()
+    end,
+    rewrite_leaders(OldUser, NewUser).
+
+kill_old_user() ->
     OldUser = whereis(user),
-    %% terminate the current user
+    %% terminate the current user's port, in a way that makes it shut down,
+    %% but without taking down the supervision tree so that the escript doesn't
+    %% fully die
+    [P] = [P || P <- element(2,process_info(whereis(user), links)), is_port(P)],
+    user ! {'EXIT', P, normal}, % pretend the port died, then the port can die!
+    OldUser.
+
+setup_new_shell() ->
+    %% terminate the current user supervision structure
     ok = supervisor:terminate_child(kernel_sup, user),
     %% start a new shell (this also starts a new user under the correct group)
     _ = user_drv:start(),
     %% wait until user_drv and user have been registered (max 3 seconds)
     ok = wait_until_user_started(3000),
+    whereis(user).
+
+setup_old_shell() ->
+    %% scan all processes for any with references to the old user and save them to
+    %% update later
+    NewUser = rebar_user:start(), % hikack IO stuff with fake user
     NewUser = whereis(user),
+    NewUser.
+
+rewrite_leaders(OldUser, NewUser) ->
     %% set any process that had a reference to the old user's group leader to the
     %% new user process. Catch the race condition when the Pid exited after the
     %% liveness check.
@@ -154,6 +183,7 @@ setup_shell() ->
             hope_for_best
     end.
 
+
 setup_paths(State) ->
     %% Add deps to path
     code:add_pathsa(rebar_state:code_paths(State, all_deps)),