From 4d6393bc4df58defbc22c5d97e28bbfdd8794fc6 Mon Sep 17 00:00:00 2001
From: Hans Nilsson <hans@erlang.org>
Date: Thu, 6 Apr 2017 19:31:13 +0200
Subject: ssh: Lazy default in get options macro

---
 lib/ssh/src/ssh.hrl                    |  5 ++++-
 lib/ssh/src/ssh_connection_handler.erl | 10 ++--------
 lib/ssh/src/ssh_options.erl            | 15 +++++++++------
 3 files changed, 15 insertions(+), 15 deletions(-)

(limited to 'lib/ssh/src')

diff --git a/lib/ssh/src/ssh.hrl b/lib/ssh/src/ssh.hrl
index e03c15454c..315310f700 100644
--- a/lib/ssh/src/ssh.hrl
+++ b/lib/ssh/src/ssh.hrl
@@ -75,9 +75,12 @@
 
 %% Option access macros
 -define(do_get_opt(C,K,O),   ssh_options:get_value(C,K,O,  ?MODULE,?LINE)).
--define(do_get_opt(C,K,O,D), ssh_options:get_value(C,K,O,D,?MODULE,?LINE)).
+-define(do_get_opt(C,K,O,D), ssh_options:get_value(C,K,O,?LAZY(D),?MODULE,?LINE)).
+
+-define(LAZY(D), fun()-> D end).
 
 -define(GET_OPT(Key,Opts),              ?do_get_opt(user_options,    Key,Opts    ) ).
+-define(GET_OPT(Key,Opts,Def),          ?do_get_opt(user_options,    Key,Opts,Def) ).
 -define(GET_INTERNAL_OPT(Key,Opts),     ?do_get_opt(internal_options,Key,Opts    ) ).
 -define(GET_INTERNAL_OPT(Key,Opts,Def), ?do_get_opt(internal_options,Key,Opts,Def) ).
 -define(GET_SOCKET_OPT(Key,Opts),       ?do_get_opt(socket_options,  Key,Opts    ) ).
diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl
index 5a13209ae3..50a29bbb53 100644
--- a/lib/ssh/src/ssh_connection_handler.erl
+++ b/lib/ssh/src/ssh_connection_handler.erl
@@ -413,14 +413,8 @@ init_connection(server, C = #connection{}, Opts) ->
     SubSystemSup =  proplists:get_value(subsystem_sup,  Sups),
     ConnectionSup = proplists:get_value(connection_sup, Sups),
 
-    Shell = ?GET_OPT(shell, Opts),
-    Exec = ?GET_OPT(exec, Opts),
-    CliSpec = case ?GET_OPT(ssh_cli, Opts) of
-                  undefined -> {ssh_cli, [Shell]};
-                  Spec -> Spec
-              end,
-    C#connection{cli_spec = CliSpec,
-		 exec = Exec,
+    C#connection{cli_spec = ?GET_OPT(ssh_cli, Opts, {ssh_cli,[?GET_OPT(shell, Opts)]}),
+		 exec =     ?GET_OPT(exec,    Opts),
 		 system_supervisor = SystemSup,
 		 sub_system_supervisor = SubSystemSup,
 		 connection_supervisor = ConnectionSup
diff --git a/lib/ssh/src/ssh_options.erl b/lib/ssh/src/ssh_options.erl
index febd3f6eef..ee3cdbb8a0 100644
--- a/lib/ssh/src/ssh_options.erl
+++ b/lib/ssh/src/ssh_options.erl
@@ -69,17 +69,20 @@ get_value(Class, Key, Opts, _CallerMod, _CallerLine) ->
     error({bad_options,Class, Key, Opts, _CallerMod, _CallerLine}).
 
 
--spec get_value(option_class(), option_key(), options(), any(),
+-spec get_value(option_class(), option_key(), options(), fun(() -> any()),
                 atom(), non_neg_integer()) -> any() | no_return().
 
-get_value(socket_options, Key, Opts, Def, _CallerMod, _CallerLine) when is_map(Opts) ->
-    proplists:get_value(Key, maps:get(socket_options,Opts), Def);
-get_value(Class, Key, Opts, Def, CallerMod, CallerLine) when is_map(Opts) ->
+get_value(socket_options, Key, Opts, DefFun, _CallerMod, _CallerLine) when is_map(Opts) ->
+    proplists:get_value(Key, maps:get(socket_options,Opts), DefFun);
+get_value(Class, Key, Opts, DefFun, CallerMod, CallerLine) when is_map(Opts) ->
     try get_value(Class, Key, Opts, CallerMod, CallerLine)
+    of
+        undefined -> DefFun();
+        Value -> Value
     catch
-        error:{badkey,Key} -> Def
+        error:{badkey,Key} -> DefFun()
     end;
-get_value(Class, Key, Opts, _Def, _CallerMod, _CallerLine) ->
+get_value(Class, Key, Opts, _DefFun, _CallerMod, _CallerLine) ->
     error({bad_options,Class, Key, Opts, _CallerMod, _CallerLine}).
 
 
-- 
cgit v1.2.3