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##### SUMMARY
<!--- Explain the problem briefly below -->
vmware_guest throws error that vmdk already exists although it does not. It is created during running the module but somehow fails. 

pyvmomi-6.7.1.2018.12

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
vmware_guest

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.8.1
```

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml
- name: Create new VM
  vmware_guest:
    hostname: "{{ vcenter_hostname }}"
    esxi_hostname: "{{ esxi_host }}"
    username: '{{domain_user}}'
    password: "{{ domain_user_password }}"
    validate_certs: False
    datacenter: TM
    name: "{{ vm_hostname }}"
    folder: "{{ vm_destination }}"      
    state: poweredon
    disk:
    - size_gb: '{{ disk_size }}'
      type: thin
      autoselect_datastore: True
    hardware:
      memory_mb: "{{ memory }}"
      num_cpus: "{{ cores }}"
      num_cpu_cores_per_socket: "{{ cores }}"
    networks:
    - name: LAN
      domain: "{{ domain }}"
      dns_servers:
      -  "{{ dns1 }}"
      -  "{{ dns2 }}"
      type: static
      ip: "{{ ip }}"
      netmask: 255.255.254.0
      gateway: 192.168.1.5
    customization:
      autologon: True
      hostname: "{{ vm_hostname }}"
      domain: "{{ domain }}"
      password: vagrant
      domainadmin: "{{ domain_user }}"
      domainadminpassword: "{{ domain_user_password }}"
      joindomain: "{{ domain }}"
      timezone: 105
      runonce:
      - powershell.exe -ExecutionPolicy Unrestricted -File C:\StartupScripts\ConfigureRemotingForAnsible.ps1 -ForceNewSSLCert -EnableCredSSP
      - powershell.exe -ExecutionPolicy Unrestricted -File C:\StartupScripts\DisableFirewall.ps1 
    wait_for_customization: yes
    template: "{{ vm_template }}"
    wait_for_ip_address: yes
```

<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
Should just create the VM.

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
Failed to create a virtual machine : Cannot complete the operation because the file or folder [EL02] ********/********.vmdk already exists"
```

if isinstance(ds, vim.Datastore) and ds.summary.freeSpace > datastore_freespace:
                
                datastore = ds
                datastore_freespace = ds.summary.freeSpace
        if datastore:
            return datastore.name
        return None
    def select_datastore(self, vm_obj=None):
        datastore = None
        datastore_name = None
        if len(self.params['disk']) != 0:
            
            if 'autoselect_datastore' in self.params['disk'][0] and self.params['disk'][0]['autoselect_datastore']:
                datastores = self.cache.get_all_objs(self.content, [vim.Datastore])
                datastores = [x for x in datastores if self.cache.get_parent_datacenter(x).name == self.params['datacenter']]
                if datastores is None or len(datastores) == 0:
                    self.module.fail_json(msg="Unable to find a datastore list when autoselecting")
                datastore_freespace = 0
                for ds in datastores:
                    if (ds.summary.freeSpace > datastore_freespace) or (ds.summary.freeSpace == datastore_freespace and not datastore):
                        
                        if 'datastore' in self.params['disk'][0] and \
                                isinstance(self.params['disk'][0]['datastore'], str) and \
                                ds.name.find(self.params['disk'][0]['datastore']) < 0:
                            continue
                        datastore = ds
                        datastore_name = datastore.name
                        datastore_freespace = ds.summary.freeSpace
            elif 'datastore' in self.params['disk'][0]:
                datastore_name = self.params['disk'][0]['datastore']