Crash on invalid recent files in prefs

[ghost]

I received a report of a crash on dupeGuru loading where the traceback shows that it crashed on HSRecentFiles initialization:

@@@
Application Specific Information:
objc[553]: garbage collection is OFF
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[**NSCFDictionary length]: unrecognized selector sent to instance 0x100224bb0'
* First throw call stack:
(
0 CoreFoundation 0x00007fff8bfbe286 __exceptionPreprocess + 198
1 libobjc.A.dylib 0x00007fff915c8d5e objc_exception_throw + 43
2 CoreFoundation 0x00007fff8c04a4ce -[NSObject doesNotRecognizeSelector:] + 190
3 CoreFoundation 0x00007fff8bfab133 __forwarding + 371
4 CoreFoundation 0x00007fff8bfaaf48 _CF_forwarding_prep_0 + 232
5 Foundation 0x00007fff8d71e1c8 -[NSFileManager fileExistsAtPath:] + 40
6 dupeGuru 0x000000010000b277 -[HSRecentFiles initWithName:menu:] + 347
7 dupeGuru 0x0000000100004657 -[DirectoryPanel initWithParentApp:] + 300
8 dupeGuru 0x0000000100003017 -[AppDelegateBase createDirectoryPanel] + 52
9 dupeGuru 0x0000000100002f7a -[AppDelegateBase awakeFromNib] + 263
10 CoreFoundation 0x00007fff8bfb52e1 -[NSObject performSelector:] + 49
11 CoreFoundation 0x00007fff8bfb5262 -[NSSet makeObjectsPerformSelector:] + 274
12 AppKit 0x00007fff8a5f4f9b -[NSIBObjectData nibInstantiateWithOwner:topLevelObjects:] + 1245
13 AppKit 0x00007fff8a5eb52f loadNib + 322
14 AppKit 0x00007fff8a5eaa28 +[NSBundle(NSNibLoading) _loadNibFile:nameTable:withZone:ownerBundle:] + 217
15 AppKit 0x00007fff8a5ea943 +[NSBundle(NSNibLoading) loadNibFile:externalNameTable:withZone:] + 141
16 AppKit 0x00007fff8a5ea886 +[NSBundle(NSNibLoading) loadNibNamed:owner:] + 364
17 AppKit 0x00007fff8a85e637 NSApplicationMain + 398
18 dupeGuru 0x0000000100000dfc start + 52
)
@@@

I could reproduce the crash by manually opening the preferences plist and adding non-string data to the "recentResults" item.

[ghost]

(from [9cdbcce6ff45]) [#184 state:fixed] Fixed a crash in HSRecentFiles when it was fed with invalid data by the prefs.
https://bitbucket.org/hsoft/dupeguru/changeset/9cdbcce6ff45/