facebook/xctool — pull request #370 by Zehhu (2014-06-17 23:31:16+00:00)
Title: Fix crash with appendDataToBuffer appending a nil NSString

We are seeing a crash with, just adding a check for nil before appending.
```
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString appendString:]: nil argument'
*** First throw call stack:
(
0 CoreFoundation 0x00007fff9041825c __exceptionPreprocess + 172
1 libobjc.A.dylib 0x00007fff8b62ee75 objc_exception_throw + 43
2 CoreFoundation 0x00007fff9041810c +[NSException raise:format:] + 204
3 CoreFoundation 0x00007fff903e7def mutateError + 159
4 xctool 0x00000001084ae257 -[LineReader dataAvailableNotification:] + 79
5 CoreFoundation 0x00007fff903e6e0c __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 12
6 CoreFoundation 0x00007fff902da8dd _CFXNotificationPost + 2893
7 Foundation 0x00007fff87f877ba -[NSNotificationCenter postNotificationName:object:userInfo:] + 68
8 Foundation 0x00007fff88080450 _performFileHandleSource + 1548
9 CoreFoundation 0x00007fff90349661 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
10 CoreFoundation 0x00007fff9033ad12 __CFRunLoopDoSources0 + 242
11 CoreFoundation 0x00007fff9033a49f __CFRunLoopRun + 831
12 CoreFoundation 0x00007fff90339f25 CFRunLoopRunSpecific + 309
13 CoreFoundation 0x00007fff903ef811 CFRunLoopRun + 97
14 xctool 0x00000001084ae931 -[SimulatorLauncher launchAndWaitForExit] + 117
15 xctool 0x00000001084ab9a8 -[OCUnitIOSAppTestRunner runTestsInSimulator:feedOutputToBlock:infraSucceeded:error:] + 286
16 xctool 0x00000001084ac0ce -[OCUnitIOSAppTestRunner runTestsAndFeedOutputTo:startupError:] + 1122
17 xctool 0x00000001084ad719 -[OCUnitTestRunner runTests] + 229
18 xctool 0x00000001084b5956 __158-[RunTestsAction blockForTestable:focusedTestCases:allTestCases:testableExecutionInfo:testableTarget:isApplicationTest:arguments:environment:testRunnerClass:]_block_invoke + 518
19 xctool 0x00000001084b6bc5 __56-[RunTestsAction runTestables:options:xcodeSubjectInfo:]_block_invoke340 + 210
20 xctool 0x00000001084b67d0 -[RunTestsAction runTestables:options:xcodeSubjectInfo:] + 3359
21 xctool 0x00000001084b517a -[RunTestsAction performActionWithOptions:xcodeSubjectInfo:] + 851
22 xctool 0x00000001084c015f -[TestAction performActionWithOptions:xcodeSubjectInfo:] + 77
23 xctool 0x00000001084a802e -[XCTool run] + 2024
24 xctool 0x00000001084a6f85 main + 542
25 xctool 0x00000001084a4da4 start + 52
)
```