Make testinstall work with gap --bare

[fingolfin]

Resolves #6346

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.86%. Comparing base (59ae437) to head (69a7a96).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6354      +/-   ##
==========================================
+ Coverage   78.83%   78.86%   +0.02%     
==========================================
  Files         685      685              
  Lines      293554   293553       -1     
  Branches     8648     8648              
==========================================
+ Hits       231432   231519      +87     
+ Misses      60314    60226      -88     
  Partials     1808     1808              

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[ThomasBreuer]

The failure is due to the fact that Test sets the global function DefaultReportDiffColors only if GAPInfo.PackagesLoaded.gapdoc is bound, which is not the case in the "bare" situation.

As far as I see, this is just about a few text constants. We could set them as in the current GAPDoc's TextAttr if GAPDoc is not available.

[fingolfin]

I've added a commit to deal with the DefaultReportDiffColors issue. Let's see if it works.

[fingolfin]

Only failure now is in tst/testinstall/package.tst which loads mockpkg which in turn "needs" GAPDoc, which then gets loaded and prints a banner.

I won't get that done for GAP 4.16.0. But I've restricted the other remaining changes from this PR into PR #6406

[ThomasBreuer]

Only failure now is in tst/testinstall/package.tst which loads mockpkg which in turn "needs" GAPDoc, which then gets loaded and prints a banner.

I see: Some tests of package extensions are based on the assumption that some GAPDoc version is already loaded. Simply removing GAPDoc from the list of needed packages of mockpkg is not a solution.

Besides this problem, everything looks well. Thanks for this work.