3 files changed, 17 insertions, 8 deletions
diff --git a/lib/stdlib/src/array.erl b/lib/stdlib/src/array.erl
index a237eaa489..939b1fb488 100644
--- a/lib/stdlib/src/array.erl
+++ b/lib/stdlib/src/array.erl
@@ -290,7 +290,7 @@ new(Size, Fixed, Default) ->
 	end,
     #array{size = Size, max = M, default = Default, elements = E}.
 
--spec find_max(integer(), integer()) -> integer().
+-spec find_max(integer(), non_neg_integer()) -> non_neg_integer().
 
 find_max(I, M) when I >= M ->
     find_max(I, ?extend(M));
diff --git a/lib/stdlib/src/io.erl b/lib/stdlib/src/io.erl
index f510f61e9f..5d5773c80c 100644
--- a/lib/stdlib/src/io.erl
+++ b/lib/stdlib/src/io.erl
@@ -86,7 +86,16 @@ put_chars(Chars) ->
       CharData :: unicode:chardata().
 
 put_chars(Io, Chars) ->
-    o_request(Io, {put_chars,unicode,Chars}, put_chars).
+    put_chars(Io, unicode, Chars).
+
+%% This function is here to make the erlang:raise in o_request actually raise to
+%% a valid function.
+-spec put_chars(IoDevice, Encoding, CharData) -> 'ok' when
+      IoDevice :: device(),
+      Encoding :: unicode,
+      CharData :: unicode:chardata().
+put_chars(Io, Encoding, Chars) ->
+    o_request(Io, {put_chars,Encoding,Chars}, put_chars).
 
 -spec nl() -> 'ok'.
 
diff --git a/lib/stdlib/src/string.erl b/lib/stdlib/src/string.erl
index f5d271c06d..cf48b882e4 100644
--- a/lib/stdlib/src/string.erl
+++ b/lib/stdlib/src/string.erl
@@ -691,9 +691,9 @@ uppercase_list(CPs0, Changed) ->
 uppercase_bin(CP1, <<CP2/utf8, Bin/binary>>, _Changed)
   when $a =< CP1, CP1 =< $z, CP2 < 256 ->
     [CP1-32|uppercase_bin(CP2, Bin, true)];
-uppercase_bin(CP1, <<CP2/utf8, Bin/binary>>, _Changed)
+uppercase_bin(CP1, <<CP2/utf8, Bin/binary>>, Changed)
   when CP1 < 128, CP2 < 256 ->
-    [CP1|uppercase_bin(CP2, Bin, false)];
+    [CP1|uppercase_bin(CP2, Bin, Changed)];
 uppercase_bin(CP1, Bin, Changed) ->
     case unicode_util:uppercase([CP1|Bin]) of
         [CP1|CPs] ->
@@ -732,9 +732,9 @@ lowercase_list(CPs0, Changed) ->
 lowercase_bin(CP1, <<CP2/utf8, Bin/binary>>, _Changed)
   when $A =< CP1, CP1 =< $Z, CP2 < 256 ->
     [CP1+32|lowercase_bin(CP2, Bin, true)];
-lowercase_bin(CP1, <<CP2/utf8, Bin/binary>>, _Changed)
+lowercase_bin(CP1, <<CP2/utf8, Bin/binary>>, Changed)
   when CP1 < 128, CP2 < 256 ->
-    [CP1|lowercase_bin(CP2, Bin, false)];
+    [CP1|lowercase_bin(CP2, Bin, Changed)];
 lowercase_bin(CP1, Bin, Changed) ->
     case unicode_util:lowercase([CP1|Bin]) of
         [CP1|CPs] ->
@@ -773,9 +773,9 @@ casefold_list(CPs0, Changed) ->
 casefold_bin(CP1, <<CP2/utf8, Bin/binary>>, _Changed)
   when $A =< CP1, CP1 =< $Z, CP2 < 256 ->
     [CP1+32|casefold_bin(CP2, Bin, true)];
-casefold_bin(CP1, <<CP2/utf8, Bin/binary>>, _Changed)
+casefold_bin(CP1, <<CP2/utf8, Bin/binary>>, Changed)
   when CP1 < 128, CP2 < 256 ->
-    [CP1|casefold_bin(CP2, Bin, false)];
+    [CP1|casefold_bin(CP2, Bin, Changed)];
 casefold_bin(CP1, Bin, Changed) ->
     case unicode_util:casefold([CP1|Bin]) of
         [CP1|CPs] ->