[RocksDB] Call to 'std::stoi()' in 'RocksDBKVStore::getStatFromProperties()' throws 'std::out_of_range'

(gdb) bt

#0  0x00007f5729ee91d7 in raise () from /usr/lib64/libc-2.17.so

#1  0x00007f5729eea8c8 in abort () from /usr/lib64/libc-2.17.so

#2  0x00007f572a7edac5 in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib64/libstdc++.so.6.0.19

#3  0x000000000043beca in backtrace_terminate_handler () at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/utilities/terminate_handler.cc:103

#4  0x00007f572a7eba36 in ?? () from /usr/lib64/libstdc++.so.6.0.19

#5  0x00007f572a7eba63 in std::terminate() () from /usr/lib64/libstdc++.so.6.0.19

#6  0x00007f572a7ebc83 in __cxa_throw () from /usr/lib64/libstdc++.so.6.0.19

#7  0x00007f572a840a97 in std::__throw_out_of_range(char const*) () from /usr/lib64/libstdc++.so.6.0.19

#8  0x00007f5725b61464 in __stoa<long, int, char, int> (__convf=<optimized out>, __name=0x7f5725b896ff "stoi", __idx=0x0, __str=0x7f54c6386fa8 <Address 0x7f54c6386fa8 out of bounds>) at /usr/include/c++/4.8.2/ext/string_conversions.h:70

#9  stoi (__base=10, __idx=0x0, __str=<error reading variable: Cannot access memory at address 0x7f54c6386f90>) at /usr/include/c++/4.8.2/bits/basic_string.h:2825

#10 RocksDBKVStore::getStatFromProperties (this=this@entry=0x7f569bff5c00, cf=cf@entry=RocksDBKVStore::Default, property=<error reading variable: Cannot access memory at address 0xffffffffffffffe8>, value=@0x7f54d2fec650: 140012354615536)

    at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/rocksdb-kvstore/rocksdb-kvstore.cc:1457

#11 0x00007f5725b665d6 in RocksDBKVStore::getStat (this=0x7f569bff5c00, name_=<optimized out>, value=@0x7f54d2fec650: 140012354615536) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/rocksdb-kvstore/rocksdb-kvstore.cc:690

#12 0x00007f5725ae7b0a in KVBucket::getKVStoreStat (this=<optimized out>, name=0x7f5725b8a37c "default_kTotalSstFilesSize", value=@0x7f54d2fec6c0: 0, option=<optimized out>) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/kv_bucket.cc:2205

#13 0x00007f5725aa2407 in EventuallyPersistentEngine::doEngineStats (this=0x7f569bff5000, cookie=0x7f54d2ffc950, add_stat=0x7f5725af1880 <add_stat(char const*, uint16_t, char const*, uint32_t, gsl::not_null<void const*>)>)

    at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/ep_engine.cc:2828

#14 0x00007f5725aa9f90 in EventuallyPersistentEngine::getStats (this=0x7f569bff5000, this@entry=<error reading variable: Cannot access memory at address 0x7f54d2ffc8e8>, cookie=0x7f54d2ffc950, stat_key=0x0, nkey=0, 

    add_stat=0x7f5725af1880 <add_stat(char const*, uint16_t, char const*, uint32_t, gsl::not_null<void const*>)>) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/ep_engine.cc:3741

std::string out;

if (!db->rdb->GetProperty(cfh, property, &out)) {

    return false;

}

value += std::stoi(out);