[Issue 24165] New: Failed readf leaves File in inconsistent state

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=24165

          Issue ID: 24165
           Summary: Failed readf leaves File in inconsistent state
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: phobos
          Assignee: nobody at puremagic.com
          Reporter: snarwin+bugzilla at gmail.com

Example:

---
$ echo "-hello" > input
$ cat example.d 
import std.stdio, std.format, std.algorithm;

void main()
{
        auto f = File("input");
        int n;
        try f.readf("%d", n);
        catch (Exception e) {}
        f.byChunk(1).copy(stdout.lockingBinaryWriter);
}
$ dmd -run example.d
hhello
---

After the failed call to File.readf, subsequent reads from `f` result in
corrupted data.

--