[Issue 15293] New: File().byLine().map!toUpper throws UnicodeException at src\rt\util\utf.d(290): invalid UTF-8 sequence on pure ASCII file

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15293

          Issue ID: 15293
           Summary: File().byLine().map!toUpper throws
                    UnicodeException at src\rt\util\utf.d(290): invalid UTF-8
                    sequence on pure ASCII file
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Windows
            Status: NEW
          Severity: normal
          Priority: P1
         Component: druntime
          Assignee: nobody at puremagic.com
          Reporter: heiko.honrath at web.de

Created attachment 1561
  --> https://issues.dlang.org/attachment.cgi?id=1561&action=edit
ASCII-textfile which throws UTF8 exception

File().byLine().map!toUpper throws UnicodeException at src\rt\util\utf.d(290):
invalid UTF-8 sequence
on pure ASCII file

.map!toLower throws at a different location with the same file

If neither toLower nor toUpper are used, the file is read completely.

program generator.d:

module generator;

// 2015-11-05
// dmd2.069
// built with: rdmd --build-only --force -version=WindowsXP -version=Unicode
-release -O generator.d
// to reproduce run: generator gentest.txt
import std.stdio, std.algorithm, std.string, std.format;

void main(string[] args) {
    int line_number = 1;
    auto gen = File(args.length > 1 ? args[1] : "gentest.txt")
               .byLine()
               .map!chomp
               .map!toUpper
               //~ .map!toLower
               .map!(line => format("Line %4s: %s", line_number++, line));

    writefln("%-(%s\n%)", gen);
}

--