From 8451f6e412bf8991c60d67805c5250d58ce702e1 Mon Sep 17 00:00:00 2001
From: Hans Bolinder <hasse@erlang.org>
Date: Thu, 28 Jun 2018 09:21:35 +0200
Subject: stdlib: Fix a 'chars_limit' bug

---
 lib/stdlib/src/io_lib_pretty.erl | 12 +++++++++---
 lib/stdlib/test/io_SUITE.erl     | 10 ++++++++--
 2 files changed, 17 insertions(+), 5 deletions(-)

(limited to 'lib/stdlib')

diff --git a/lib/stdlib/src/io_lib_pretty.erl b/lib/stdlib/src/io_lib_pretty.erl
index dca1b37ef3..ba9d9e8434 100644
--- a/lib/stdlib/src/io_lib_pretty.erl
+++ b/lib/stdlib/src/io_lib_pretty.erl
@@ -722,7 +722,7 @@ printable_list(L, _D, T, latin1) when T < 0 ->
     io_lib:printable_latin1_list(L);
 printable_list(L, _D, T, Enc) when T >= 0 ->
     case slice(L, tsub(T, 2)) of
-        {prefix, ""} ->
+        false ->
             false;
         {prefix, Prefix} when Enc =:= latin1 ->
             io_lib:printable_latin1_list(Prefix) andalso {true, Prefix};
@@ -738,11 +738,17 @@ printable_list(L, _D, T, _Uni) when T < 0->
     io_lib:printable_list(L).
 
 slice(L, N) ->
-    case string:length(L) =< N of
+    try string:length(L) =< N of
         true ->
             all;
         false ->
-            {prefix, string:slice(L, 0, N)}
+            case string:slice(L, 0, N) of
+                "" ->
+                    false;
+                Prefix ->
+                    {prefix, Prefix}
+            end
+    catch _:_ -> false
     end.
 
 printable_bin0(Bin, D, T, Enc) ->
diff --git a/lib/stdlib/test/io_SUITE.erl b/lib/stdlib/test/io_SUITE.erl
index 91fe1133f6..79cee54335 100644
--- a/lib/stdlib/test/io_SUITE.erl
+++ b/lib/stdlib/test/io_SUITE.erl
@@ -31,7 +31,8 @@
          otp_10836/1, io_lib_width_too_small/1,
          io_with_huge_message_queue/1, format_string/1,
 	 maps/1, coverage/1, otp_14178_unicode_atoms/1, otp_14175/1,
-         otp_14285/1, limit_term/1, otp_14983/1, otp_15103/1]).
+         otp_14285/1, limit_term/1, otp_14983/1, otp_15103/1,
+         otp_15159/1]).
 
 -export([pretty/2, trf/3]).
 
@@ -63,7 +64,7 @@ all() ->
      io_lib_print_binary_depth_one, otp_10302, otp_10755, otp_10836,
      io_lib_width_too_small, io_with_huge_message_queue,
      format_string, maps, coverage, otp_14178_unicode_atoms, otp_14175,
-     otp_14285, limit_term, otp_14983, otp_15103].
+     otp_14285, limit_term, otp_14983, otp_15103, otp_15159].
 
 %% Error cases for output.
 error_1(Config) when is_list(Config) ->
@@ -2633,3 +2634,8 @@ otp_15103(_Config) ->
     "[{a,\n  b,\n  c},\n {a,\n  b,...},\n {a,...},\n {...}|...]" =
         lists:flatten(S5),
     ok.
+
+otp_15159(_Config) ->
+    "[atom]" =
+        lists:flatten(io_lib:format("~p", [[atom]], [{chars_limit,5}])),
+    ok.
-- 
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