ID 361671 - Hash values are inconsistent once a scalar data channel is selected

Problem summary
Hash values are inconsistent once a scalar data channel is selected

Customer reported version
3.3v1
Customer reported platform
rhel5

Steps to reproduce

1) Open Example Head

2) In the Python Console run:

ch = mari.current.geo().findChannel('Specular_Head_Geo')
print ch.name() + " is " + ch.hash()

3) Now select the channel Specular_Head_Geo (or any channel that has scalar data enabled)

4) Again, run:

ch = mari.current.geo().findChannel('Specular_Head_Geo')
print ch.name() + " is " + ch.hash()

5) Notice that the Hash results are different

Workaround
Unknown. 

Reproduced by support
This bug has been reproduced in:
3.4v1 - Win 7, CentOS 7.5, OSX 10.12.4
3.3v1
3.1v3
3.1v1
3.0v4
2.6v5 - Win 7, CentOS 7.5

Unable to reproduce bug in:
4.1v1 
4.0v1

Earliest version tested
2.6v5 - no further testing

Expected behaviour
Channel hash should remain constant, as with channels that are not scalar

Actual behaviour
Channel hashes were inconsistent before and after selection of a scalar data channel