[stdlib] Add control sequence modifier 'l'

The modifier 'l' can be used for turning off the string recognition of
~p and ~P.

1 files changed, 40 insertions, 2 deletions

diff --git a/lib/stdlib/test/io_SUITE.erl b/lib/stdlib/test/io_SUITE.erl
index 65a112c966..aa698ecaa2 100644
--- a/lib/stdlib/test/io_SUITE.erl
+++ b/lib/stdlib/test/io_SUITE.erl
@@ -29,7 +29,8 @@
          manpage/1, otp_6708/1, otp_7084/1, otp_7421/1,
 	 io_lib_collect_line_3_wb/1, cr_whitespace_in_string/1,
 	 io_fread_newlines/1, otp_8989/1, io_lib_fread_literal/1,
-	 io_lib_print_binary_depth_one/1, otp_10302/1, otp_10836/1]).
+	 io_lib_print_binary_depth_one/1, otp_10302/1, otp_10755/1,
+	 otp_10836/1]).
 
 %-define(debug, true).
 
@@ -65,7 +66,7 @@ all() ->
      manpage, otp_6708, otp_7084, otp_7421,
      io_lib_collect_line_3_wb, cr_whitespace_in_string,
      io_fread_newlines, otp_8989, io_lib_fread_literal,
-     io_lib_print_binary_depth_one, otp_10302, otp_10836].
+     io_lib_print_binary_depth_one, otp_10302, otp_10755, otp_10836].
 
 groups() -> 
     [].
@@ -2085,3 +2086,40 @@ otp_10836(Suite) when is_list(Suite) ->
     S = io_lib:format("~ts", [[<<"äpple"/utf8>>, <<"äpple">>]]),
     "äppleäpple" = lists:flatten(S),
     ok.
+
+otp_10755(doc) ->
+    "OTP-10755. The 'l' modifier";
+otp_10755(Suite) when is_list(Suite) ->
+    S = "string",
+    "\"string\"" = fmt("~p", [S]),
+    "[115,116,114,105,110,103]" = fmt("~lp", [S]),
+    "\"string\"" = fmt("~P", [S, 2]),
+    "[115|...]" = fmt("~lP", [S, 2]),
+    {'EXIT',{badarg,_}} = (catch fmt("~ltp", [S])),
+    {'EXIT',{badarg,_}} = (catch fmt("~tlp", [S])),
+    {'EXIT',{badarg,_}} = (catch fmt("~ltP", [S])),
+    {'EXIT',{badarg,_}} = (catch fmt("~tlP", [S])),
+    Text =
+        "-module(l_mod).\n"
+        "-export([t/0]).\n"
+        "t() ->\n"
+        "    S = \"string\",\n"
+        "    io:format(\"~ltp\", [S]),\n"
+        "    io:format(\"~tlp\", [S]),\n"
+        "    io:format(\"~ltP\", [S, 1]),\n"
+        "    io:format(\"~tlP\", [S, 1]).\n",
+    {ok,l_mod,[{_File,Ws}]} = compile_file("l_mod.erl", Text, Suite),
+    ["format string invalid (invalid control ~lt)",
+     "format string invalid (invalid control ~tl)",
+     "format string invalid (invalid control ~lt)",
+     "format string invalid (invalid control ~tl)"] =
+        [lists:flatten(M:format_error(E)) || {_L,M,E} <- Ws],
+    ok.
+
+compile_file(File, Text, Config) ->
+    PrivDir = ?privdir(Config),
+    Fname = filename:join(PrivDir, File),
+    ok = file:write_file(Fname, Text),
+    try compile:file(Fname, [return])
+    after ok %file:delete(Fname)
+    end.