Loading multiple Muon files causes excess group workspaces to be created.

[Samuel Jackson]

Selecting multiple muon nexus files and then loading them causes Mantid to create a number of empty group workspaces (one for each file). This issue only appears to happen when loading Muon nexus files, so I'm guessing this may be an issue in LoadMuonNexus2.

[Arturs Bekasovs]

Doesn't seem to be a problem with LoadMuonNexus2 per se, as the same behavior is observed with OFFSPEC raw files when LoadRaw is used.

[Arturs Bekasovs]

Updated test to expose the problem.

Obviously failing for now.

Refs #7852

Changeset: c9bed73e4ee27eb1293b16f526c8d5fc05205141

[Arturs Bekasovs]

Solved the problem by removing old groups after regrouping.

Refs #7852

Changeset: e74988d74e2090936e4b6ad576a30eb6e4705b4d

[Arturs Bekasovs]

Tester:

That's a pretty simple one.

1. Run MantidPlot.
2. Open Load dialog.
3. Select the following files from AutoTestData: MUSR00015189.nxs, MUSR00015190.nxs, MUSR00015191.nxs (all of them together)
4. Leave all the other parameters to default, and run the load.
5. Make sure the ONLY workspace group created is "MultiFiles", and that it contains 6 workspaces (2 for every file). Nothing apart from that should be created.
6. Now try doing that with a set of non-muon files, e.g. LOQ48094.raw, LOQ48097.raw, LOQ48098.raw and make sure it works as described above as well.

[Roman Tolchenov]

Merge remote-tracking branch 'origin/feature/7852_excess_groups'

[Stuart Campbell]

This ticket has been transferred to github issue ​8697