[musl] strftime() unexpectedly modifies errno

[Yossi Gottlieb <yossigo@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 555 bytes --]

It seems like strftime() unexpectedly modifies errno, which is always set
to EINVAL when it returns. Looks like it's not related to any specific
format.

Here's an example:

#include <stdio.h>
#include <sys/time.h>
#include <time.h>
#include <errno.h>

int main(int argc, char *argv[])
{
    time_t now = time(NULL);
    struct tm *tm = localtime(&now);
    char buf[100];

    errno = 0;
    size_t len = strftime(buf, sizeof(buf), "%d %b %Y %H:%M:%S.", tm);

    printf("len=%zu\n", len);
    printf("buf=%s\n", buf);
    printf("errno=%d\n", errno);
}

[-- Attachment #2: Type: text/html, Size: 776 bytes --]