Merge branch 'raimo/io_lib_fread/OTP-9439' into dev

* raimo/io_lib_fread/OTP-9439:
  Code cleanup, unduplicate test for whitespace
  EOF before first field is only ok for first character in io:fread
  At end of input ask for more also for for literal format characters

2 files changed, 54 insertions, 40 deletions

diff --git a/lib/stdlib/src/io_lib_fread.erl b/lib/stdlib/src/io_lib_fread.erl
index 52aa4d073c..ded1346097 100644
--- a/lib/stdlib/src/io_lib_fread.erl
+++ b/lib/stdlib/src/io_lib_fread.erl
@@ -24,6 +24,10 @@
 
 -import(lists, [reverse/1,reverse/2]).
 
+-define(is_whitespace(C),
+	((C) =:= $\s orelse (C) =:= $\t
+	 orelse (C) =:= $\r orelse (C) =:= $\n)).
+
 %%-----------------------------------------------------------------------
 
 %% fread(Continuation, CharList, FormatString)
@@ -106,31 +110,27 @@ fread_line(Format0, Line, N0, Results0, More, Newline) ->
 fread(Format, Line) ->
     fread(Format, Line, 0, []).
 
-fread([$~|Format0], Line, N, Results) ->
+fread([$~|Format0]=AllFormat, Line, N, Results) ->
     {Format,F,Sup,Unicode} = fread_field(Format0),
-    fread1(Format, F, Sup, Unicode, Line, N, Results, Format0);
-fread([$\s|Format], Line, N, Results) ->
-    fread_skip_white(Format, Line, N, Results);
-fread([$\t|Format], Line, N, Results) ->
-    fread_skip_white(Format, Line, N, Results);
-fread([$\r|Format], Line, N, Results) ->
-    fread_skip_white(Format, Line, N, Results);
-fread([$\n|Format], Line, N, Results) ->
+    fread1(Format, F, Sup, Unicode, Line, N, Results, AllFormat);
+fread([C|Format], Line, N, Results) when ?is_whitespace(C) ->
     fread_skip_white(Format, Line, N, Results);
 fread([C|Format], [C|Line], N, Results) ->
     fread(Format, Line, N+1, Results);
 fread([_F|_Format], [_C|_Line], _N, _Results) ->
     fread_error(input);
+fread([_|_]=Format, [], N, Results) ->
+    {more,Format,N,Results};
+fread([_|_], eof, 0, []) ->
+    %% This is at start of input so no error.
+    eof;
+fread([_|_], eof, _N, _Results) ->
+    %% This is an error as there is no more input.
+    fread_error(input);
 fread([], Line, _N, Results) ->
     {ok,reverse(Results),Line}.
 
-fread_skip_white(Format, [$\s|Line], N, Results) ->
-    fread_skip_white(Format, Line, N+1, Results);
-fread_skip_white(Format, [$\t|Line], N, Results) ->
-    fread_skip_white(Format, Line, N+1, Results);
-fread_skip_white(Format, [$\r|Line], N, Results) ->
-    fread_skip_white(Format, Line, N+1, Results);
-fread_skip_white(Format, [$\n|Line], N, Results) ->
+fread_skip_white(Format, [C|Line], N, Results) when ?is_whitespace(C) ->
     fread_skip_white(Format, Line, N+1, Results);
 fread_skip_white(Format, Line, N, Results) ->
     fread(Format, Line, N, Results).
@@ -166,9 +166,9 @@ fread1([$l|Format], _F, Sup, _U, Line, N, Res, _AllFormat) ->
     fread(Format, Line, N, fread_result(Sup, N, Res));
 fread1(_Format, _F, _Sup, _U, [], N, Res, AllFormat) ->
     %% Need more input here.
-    {more,[$~|AllFormat],N,Res};
-fread1(_Format, _F, _Sup, _U, eof, _N, [], _AllFormat) ->
-    %% This is at start of format string so no error.
+    {more,AllFormat,N,Res};
+fread1(_Format, _F, _Sup, _U, eof, 0, [], _AllFormat) ->
+    %% This is at start of input so no error.
     eof;
 fread1(_Format, _F, _Sup, _U, eof, _N, _Res, _AllFormat) ->
     %% This is an error as there is no more input.
@@ -386,26 +386,16 @@ fread_string_cs(Line0, N0, true) ->
 %% fread_digits(Line, N, Base, Characters)
 %%  Read segments of things, return "thing" characters in reverse order.
 
-fread_skip_white([$\s|Line]) -> fread_skip_white(Line);
-fread_skip_white([$\t|Line]) -> fread_skip_white(Line);
-fread_skip_white([$\r|Line]) -> fread_skip_white(Line);
-fread_skip_white([$\n|Line]) -> fread_skip_white(Line);
+fread_skip_white([C|Line]) when ?is_whitespace(C) ->
+    fread_skip_white(Line);
 fread_skip_white(Line) -> Line.
 
-fread_skip_white([$\s|Line], N) ->
-    fread_skip_white(Line, N+1);
-fread_skip_white([$\t|Line], N) ->
-    fread_skip_white(Line, N+1);
-fread_skip_white([$\r|Line], N) ->
-    fread_skip_white(Line, N+1);
-fread_skip_white([$\n|Line], N) ->
+fread_skip_white([C|Line], N) when ?is_whitespace(C) ->
     fread_skip_white(Line, N+1);
 fread_skip_white(Line, N) -> {Line,N}.
 
-fread_skip_latin1_nonwhite([$\s|Line], N, Cs) -> {[$\s|Line],N,Cs};
-fread_skip_latin1_nonwhite([$\t|Line], N, Cs) -> {[$\t|Line],N,Cs};
-fread_skip_latin1_nonwhite([$\r|Line], N, Cs) -> {[$\r|Line],N,Cs};
-fread_skip_latin1_nonwhite([$\n|Line], N, Cs) -> {[$\n|Line],N,Cs};
+fread_skip_latin1_nonwhite([C|Line], N, Cs) when ?is_whitespace(C) ->
+    {[C|Line],N,Cs};
 fread_skip_latin1_nonwhite([C|Line], N, []) when C > 255 ->
     {[C|Line],N,error};
 fread_skip_latin1_nonwhite([C|Line], N, Cs) when C > 255 ->
@@ -414,10 +404,8 @@ fread_skip_latin1_nonwhite([C|Line], N, Cs) ->
     fread_skip_latin1_nonwhite(Line, N+1, [C|Cs]);
 fread_skip_latin1_nonwhite([], N, Cs) -> {[],N,Cs}.
 
-fread_skip_nonwhite([$\s|Line], N, Cs) -> {[$\s|Line],N,Cs};
-fread_skip_nonwhite([$\t|Line], N, Cs) -> {[$\t|Line],N,Cs};
-fread_skip_nonwhite([$\r|Line], N, Cs) -> {[$\r|Line],N,Cs};
-fread_skip_nonwhite([$\n|Line], N, Cs) -> {[$\n|Line],N,Cs};
+fread_skip_nonwhite([C|Line], N, Cs) when ?is_whitespace(C) ->
+    {[C|Line],N,Cs};
 fread_skip_nonwhite([C|Line], N, Cs) ->
     fread_skip_nonwhite(Line, N+1, [C|Cs]);
 fread_skip_nonwhite([], N, Cs) -> {[],N,Cs}.
diff --git a/lib/stdlib/test/io_SUITE.erl b/lib/stdlib/test/io_SUITE.erl
index 54a98985cd..bb02a879c2 100644
--- a/lib/stdlib/test/io_SUITE.erl
+++ b/lib/stdlib/test/io_SUITE.erl
@@ -27,7 +27,7 @@
          otp_6282/1, otp_6354/1, otp_6495/1, otp_6517/1, otp_6502/1,
          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_fread_newlines/1, otp_8989/1, io_lib_fread_literal/1]).
 
 %-define(debug, true).
 
@@ -62,7 +62,7 @@ all() ->
      otp_6282, otp_6354, otp_6495, otp_6517, otp_6502,
      manpage, otp_6708, otp_7084, otp_7421,
      io_lib_collect_line_3_wb, cr_whitespace_in_string,
-     io_fread_newlines, otp_8989].
+     io_fread_newlines, otp_8989, io_lib_fread_literal].
 
 groups() -> 
     [].
@@ -1995,3 +1995,29 @@ otp_8989(Suite) when is_list(Suite) ->
     ?line "Hel " = fmt("~-4.*s", [3,Hello]),
     ?line "Hel " = fmt("~*.*s", [-4,3,Hello]),
     ok.
+
+io_lib_fread_literal(doc) ->
+    "OTP-9439 io_lib:fread bug for literate at end";
+io_lib_fread_literal(Suite) when is_list(Suite) ->
+    ?line {more,"~d",0,""} = io_lib:fread("~d", ""),
+    ?line {error,{fread,integer}} = io_lib:fread("~d", " "),
+    ?line {more,"~d",1,""} = io_lib:fread(" ~d", " "),
+    ?line {ok,[17],"X"} = io_lib:fread(" ~d", " 17X"),
+    %%
+    ?line {more,"d",0,""} = io_lib:fread("d", ""),
+    ?line {error,{fread,input}} = io_lib:fread("d", " "),
+    ?line {more,"d",1,""} = io_lib:fread(" d", " "),
+    ?line {ok,[],"X"} = io_lib:fread(" d", " dX"),
+    %%
+    ?line {done,eof,_} = io_lib:fread([], eof, "~d"),
+    ?line {done,eof,_} = io_lib:fread([], eof, " ~d"),
+    ?line {more,C1} = io_lib:fread([], " \n", " ~d"),
+    ?line {done,{error,{fread,input}},_} = io_lib:fread(C1, eof, " ~d"),
+    ?line {done,{ok,[18]},""} = io_lib:fread(C1, "18\n", " ~d"),
+    %%
+    ?line {done,eof,_} = io_lib:fread([], eof, "d"),
+    ?line {done,eof,_} = io_lib:fread([], eof, " d"),
+    ?line {more,C2} = io_lib:fread([], " \n", " d"),
+    ?line {done,{error,{fread,input}},_} = io_lib:fread(C2, eof, " d"),
+    ?line {done,{ok,[]},[]} = io_lib:fread(C2, "d\n", " d"),
+    ok.