From fc130e699774228f396dc6f4fef4b654edc00451 Mon Sep 17 00:00:00 2001
From: Jonas Falkevik <jonas.falkevik@mobilearts.com>
Date: Fri, 4 Apr 2014 22:17:34 +0200
Subject: Fix shell crash when in switch command mode

The user_drv process can crash if ctrl-y is pressed when in switch command mode (ctrl-g).
This is due to switch mode using edlin to parse the input.
And edlin uses the process dictionary to store the kill_buffer.
However the kill_buffer is undefined if not initialized by edlin:init/0
which makes the user_drv process crash since edlin is calling list:reverse/2 with undefined.

Fix calles edlin:init/0 once before server_loop is entered.
---
 lib/kernel/src/user_drv.erl | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'lib')

diff --git a/lib/kernel/src/user_drv.erl b/lib/kernel/src/user_drv.erl
index e6ce85c379..f7b2be1ca3 100644
--- a/lib/kernel/src/user_drv.erl
+++ b/lib/kernel/src/user_drv.erl
@@ -133,6 +133,10 @@ server1(Iport, Oport, Shell) ->
 		flatten(io_lib:format("~ts\n",
 				      [erlang:system_info(system_version)]))},
 	       Iport, Oport),
+
+    %% Init edlin used by switch command
+    edlin:init(),
+
     %% Enter the server loop.
     server_loop(Iport, Oport, Curr, User, Gr, queue:new()).
 
-- 
cgit v1.2.3


From d756777e731fe7a8d63690ca0246c9cbd53dea75 Mon Sep 17 00:00:00 2001
From: Peter Andersson <peppe@erlang.org>
Date: Wed, 22 Apr 2015 14:09:48 +0200
Subject: Fix problem with unitialized edlin text buffer

Also make it possible to copy text buffer from current group
process to the JCL mode
---
 lib/kernel/src/user_drv.erl |  6 +++---
 lib/stdlib/src/edlin.erl    | 16 +++++++++++++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

(limited to 'lib')

diff --git a/lib/kernel/src/user_drv.erl b/lib/kernel/src/user_drv.erl
index f7b2be1ca3..380c685869 100644
--- a/lib/kernel/src/user_drv.erl
+++ b/lib/kernel/src/user_drv.erl
@@ -134,9 +134,6 @@ server1(Iport, Oport, Shell) ->
 				      [erlang:system_info(system_version)]))},
 	       Iport, Oport),
 
-    %% Init edlin used by switch command
-    edlin:init(),
-
     %% Enter the server loop.
     server_loop(Iport, Oport, Curr, User, Gr, queue:new()).
 
@@ -319,6 +316,9 @@ handle_escape(Iport, Oport, User, Gr, IOQueue) ->
 
 	_ ->					% {ok,jcl} | undefined
 	    io_request({put_chars,unicode,"\nUser switch command\n"}, Iport, Oport),
+	    %% init edlin used by switch command and have it copy the
+	    %% text buffer from current group process
+	    edlin:init(gr_cur_pid(Gr)),
 	    server_loop(Iport, Oport, User, switch_loop(Iport, Oport, Gr), IOQueue)
     end.
 
diff --git a/lib/stdlib/src/edlin.erl b/lib/stdlib/src/edlin.erl
index b3bc5f6d92..362669545e 100644
--- a/lib/stdlib/src/edlin.erl
+++ b/lib/stdlib/src/edlin.erl
@@ -21,7 +21,7 @@
 %% A simple Emacs-like line editor.
 %% About Latin-1 characters: see the beginning of erl_scan.erl.
 
--export([init/0,start/1,start/2,edit_line/2,prefix_arg/1]).
+-export([init/0,init/1,start/1,start/2,edit_line/2,prefix_arg/1]).
 -export([erase_line/1,erase_inp/1,redraw_line/1]).
 -export([length_before/1,length_after/1,prompt/1]).
 -export([current_line/1, current_chars/1]).
@@ -44,6 +44,20 @@
 init() ->
     put(kill_buffer, []).
 
+init(Pid) ->
+    %% copy the kill_buffer from the process Pid
+    CopiedKillBuf =
+	case erlang:process_info(Pid, dictionary) of
+	    {dictionary,Dict} ->
+		case proplists:get_value(kill_buffer, Dict) of
+		    undefined -> [];
+		    Buf       -> Buf
+		end;
+	    undefined ->
+		[]
+	end,
+    put(kill_buffer, CopiedKillBuf).
+
 %% start(Prompt)
 %% edit(Characters, Continuation)
 %%  Return
-- 
cgit v1.2.3