1. Description
In some instances after pulling an update from Collab, Unity crashes with a "System out of memory" error. Unity is trying to allocate roughly 30 petabytes of memory after LaunchAutomaticMergeTool function.

2. Repro Steps:
a) Open a Collab-enabled project using v2.0.0-preview.17 of the Collaborate package with a pending update.
b) Pull an update.

Expected: Update downloads changes without any errors.
Actual: In some instances, an out of memory crash occurs with the following stack trace:

2019-1010 14:56:54 GMT 46.436081 Collab Log *8876 4b712b78f4c5d6b4f908be190c6ebeba FUNC END ["LaunchAutomaticMergeTool"] [] [] 0.101815s DynamicHeapAllocator allocation probe 1 failed - Could not get memory for large allocation 30118299249410058.
DynamicHeapAllocator allocation probe 2 failed - Could not get memory for large allocation 30118299249410058.
DynamicHeapAllocator allocation probe 3 failed - Could not get memory for large allocation 30118299249410058.
DynamicHeapAllocator allocation probe 4 failed - Could not get memory for large allocation 30118299249410058.
DynamicHeapAllocator out of memory - Could not get memory for large allocation 30118299249410058!
Could not allocate memory: System out of memory!
Trying to allocate: 30118299249410058B with 16 alignment. MemoryLabel: String
Allocation happened at: Line:320 in C:\buildslave\unity\build\Runtime/Core/Containers/StringStorageDefault.h
Memory overview

[ ALLOC_DEFAULT ] used: 97277792B | peak: 0B | reserved: 127926272B
[ ALLOC_TEMP_JOB_1_FRAME ] used: 0B | peak: 0B | reserved: 1048576B
[ ALLOC_TEMP_JOB_2_FRAMES ] used: 0B | peak: 0B | reserved: 1048576B
[ ALLOC_TEMP_JOB_4_FRAMES ] used: 0B | peak: 0B | reserved: 2097152B
[ ALLOC_TEMP_JOB_ASYNC ] used: 4593B | peak: 0B | reserved: 1048576B
[ ALLOC_GFX ] used: 37915072B | peak: 0B | reserved: 51380224B
[ ALLOC_CACHEOBJECTS ] used: 19913296B | peak: 0B | reserved: 60817408B
[ ALLOC_TYPETREE ] used: 2141032B | peak: 0B | reserved: 34603008B
[ ALLOC_PROFILER ] used: 1059480B | peak: 1084552B | reserved: 16777216B
[ ALLOC_PROFILER_EDITOR ] used: 22288B | peak: 31520B | reserved: 67108864B
[ ALLOC_TEMP_THREAD ] used: 32768B | peak: 0B | reserved: 53903360B
Could not allocate memory: System out of memory!
Trying to allocate: 30118299249410058B with 16 alignment. MemoryLabel: String
Allocation happened at: Line:320 in C:\buildslave\unity\build\Runtime/Core/Containers/StringStorageDefault.h
Memory overview