[Bug 37913] New: Inconsistent rounding behaviour for sprintf

[wine-bugs at winehq.org]

https://bugs.winehq.org/show_bug.cgi?id=37913

            Bug ID: 37913
           Summary: Inconsistent rounding behaviour for sprintf
           Product: Wine
           Version: unspecified
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: msvcp
          Assignee: wine-bugs at winehq.org
          Reporter: christopherwuy at gmail.com
      Distribution: ---

sample source code and output demonstrating the problem:
#include <iostream>
#include <stdio.h>
using namespace std;
int main()
{
    double a;
    a = 3.5;
    char *tmp = new char(100);
    char fmt[18] = " is %.0f";
    sprintf(tmp, fmt, a);
    cout<<endl<<a<<tmp<<endl<<endl;

    a = -4.5;
    sprintf(tmp, fmt, a);
    cout<<endl<<a<<tmp<<endl<<endl;

    a = -0.5;
    sprintf(tmp, fmt, a);
    cout<<endl<<a<<tmp<<endl<<endl;

    a = 2597.625;
    printf("%.3f", a);
    sprintf(tmp, " is %.2lf", a);
    cout<<tmp<<endl<<endl;
}

This code running by wine 's Output is:
3.5  is 4
-4.5 is -4
-0.5 is -0
2597.625 is 2597.62

while windows' output is:
3.5  is 4
-4.5 is -5
-0.5 is -1
2597.625 is 2597.63

It indicated that Wine's sprintf used rounding rule which is Round half to
even, while windows used Round half away from zero.
You can find a detailed discussion of 'similar bug' form
https://sourceware.org/bugzilla/show_bug.cgi?id=4943

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