Silently skip Steam libraries on missing drives

[HebaruSan]

Problem

System.IO.IOException: A device which does not exist was specified.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileSystemEnumerableIterator`1.CommonInit()
   at System.IO.FileSystemEnumerableIterator`1..ctor(String path, String originalUserPath, String searchPattern, SearchOption searchOption, SearchResultHandler`1 resultHandler, Boolean checkHost)
   at System.IO.Directory.EnumerateFiles(String path, String searchPattern)
   at CKAN.IO.SteamLibrary.LibraryPathGames(KVSerializer acfParser, String appPath)
   at System.Linq.Enumerable.<SelectManyIterator>d__17`2.MoveNext()
   at System.Linq.Enumerable.<ConcatIterator>d__59`1.MoveNext()
   at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
   at CKAN.IO.SteamLibrary..ctor(String libraryPath)
   at CKAN.GameInstanceManager.get_SteamLibrary()
   at CKAN.GUI.Main.OnLoad(EventArgs e)
   at System.Windows.Forms.Form.OnCreateControl()
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.WmShowWindow(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.Form.WmShowWindow(Message& m)
   at CKAN.GUI.Main.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Cause

The user had a Steam library on a drive that was no longer available. Those paths were still in the Steam config files, so CKAN was trying to check that drive for KSP instances.

Change

Now if Directory.EnumerateFiles throws an exception, we log.Warn it and ignore that path.

Fixes #4567.

[coveralls]

Coverage Report for CI Build 24488350928

Coverage decreased (-0.005%) to 85.544%

Details

• Coverage decreased (-0.005%) from the base build.
• Patch coverage: 4 uncovered changes across 1 file (2 of 6 lines covered, 33.33%).
• 18 coverage regressions across 2 files.

Uncovered Changes

File	Changed	Covered	%
Core/IO/SteamLibrary.cs	6	2	33.33%

Coverage Regressions

18 previously-covered lines in 2 files lost coverage.

File	Lines Losing Coverage	Coverage
Core/Games/KerbalSpaceProgram/GameVersionProviders/KspBuildMap.cs	15	59.41%
Core/Net/NetFileCache.cs	3	90.33%

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Coverage Stats

Relevant Lines:	14225
Covered Lines:	12015
Line Coverage:	84.46%
Relevant Branches:	2163
Covered Branches:	2004
Branch Coverage:	92.65%
Branches in Coverage %:	Yes
Coverage Strength:	1.76 hits per line

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💛 - Coveralls