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##### SUMMARY

The Git module encourages use of `StrictHostKeyChecking=no` with SSH, which makes the connection vulnerable to a MITM attack.

##### ISSUE TYPE

OpenSSH 7.5+ (2017-03-20) added a safer option which automatically accepts the key on first use but will not allow a MITM on subsequent connections: `StrictHostKeyChecking=accept-new` 

https://man.openbsd.org/ssh_config#StrictHostKeyChecking

It would be great if Ansible encouraged use of that mode by default in the documentation and to implement features such as the Git module's [`accept_hostkey`](https://github.com/ansible/ansible/blob/323d2adfcce9a53e906c2c4a40f6ac5fb32a0e68/lib/ansible/modules/git.py#L1103-L1108) feature.

##### ANSIBLE VERSION

```paste below
N/A
```

##### COMPONENT NAME
* `/modules/source_control/git.py`


'''Extract the head reference'''
    
    res = None
    if os.path.exists(headfile):
        rawdata = None
        try:
            f = open(headfile, 'r')
            rawdata = f.readline()
            f.close()
        except Exception:
            if fail_on_error and module:
                module.fail_json(msg="Unable to read %s" % headfile)
        if rawdata:
            try:
                rawdata = rawdata.replace('refs/remotes/%s' % remote, '', 1)
                refparts = rawdata.split(' ')
                newref = refparts[-1]
                nrefparts = newref.split('/', 2)
                res = nrefparts[-1].rstrip('\n')
            except Exception:
                if fail_on_error and module:
                    module.fail_json(msg="Unable to split head from '%s'" % rawdata)
    return res
def unfrackgitpath(path):