==13==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x6164d5 in contains /src/re2/./util/sparse_set.h:134:52
    #1 0x6164d5 in re2::Prog::MarkRoots(re2::SparseArray<int>*, re2::SparseSet*, std::__1::vector<int, std::__1::allocator<int> >*) /src/re2/re2/prog.cc:429:12
    #2 0x61262e in re2::Prog::Flatten() /src/re2/re2/prog.cc:371:3
    #3 0x5a0ac2 in re2::Compiler::Finish() /src/re2/re2/compile.cc:1240:10
    #4 0x59e7b3 in re2::Compiler::Compile(re2::Regexp*, bool, long) /src/re2/re2/compile.cc:1218:12
    #5 0x52750f in re2::RE2::Init(re2::StringPiece const&, re2::RE2::Options const&) /src/re2/re2/re2.cc:212:27
    #6 0x529e99 in re2::RE2::RE2(re2::StringPiece const&, re2::RE2::Options const&) /src/re2/re2/re2.cc:118:3
    #7 0x523377 in Test(re2::StringPiece, re2::RE2::Options const&, re2::StringPiece) /src/re2/re2/fuzzing/re2_fuzzer.cc:21:7
    #8 0x5257d6 in LLVMFuzzerTestOneInput /src/re2/re2/fuzzing/re2_fuzzer.cc:85:3
    #9 0x45aa71 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerLoop.cpp:556:15
    #10 0x45a1b5 in fuzzer::Fuzzer::RunOne(unsigned char const*, unsigned long, bool, fuzzer::InputInfo*, bool*) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerLoop.cpp:470:3
    #11 0x45c77a in fuzzer::Fuzzer::ReadAndExecuteSeedCorpora(std::__Fuzzer::vector<fuzzer::SizedFile, fuzzer::fuzzer_allocator<fuzzer::SizedFile> >&) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerLoop.cpp:748:5
    #12 0x45ca09 in fuzzer::Fuzzer::Loop(std::__Fuzzer::vector<fuzzer::SizedFile, fuzzer::fuzzer_allocator<fuzzer::SizedFile> >&) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerLoop.cpp:794:3
    #13 0x44bcde in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerDriver.cpp:826:6
    #14 0x4744b2 in main /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerMain.cpp:19:10
    #15 0x7f972438b82f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #16 0x4203e8 in _start (/out/re2_fuzzer+0x4203e8)

  Uninitialized value was created by a heap allocation
    #0 0x522309 in operator new[](unsigned long) /src/llvm-project/compiler-rt/lib/msan/msan_new_delete.cpp:47:37
    #1 0x611fee in SparseSet /src/re2/./util/sparse_set.h:61:24
    #2 0x611fee in re2::Prog::Flatten() /src/re2/re2/prog.cc:364:13
    #3 0x5a0ac2 in re2::Compiler::Finish() /src/re2/re2/compile.cc:1240:10
    #4 0x59e7b3 in re2::Compiler::Compile(re2::Regexp*, bool, long) /src/re2/re2/compile.cc:1218:12
    #5 0x52750f in re2::RE2::Init(re2::StringPiece const&, re2::RE2::Options const&) /src/re2/re2/re2.cc:212:27
    #6 0x529e99 in re2::RE2::RE2(re2::StringPiece const&, re2::RE2::Options const&) /src/re2/re2/re2.cc:118:3
    #7 0x523377 in Test(re2::StringPiece, re2::RE2::Options const&, re2::StringPiece) /src/re2/re2/fuzzing/re2_fuzzer.cc:21:7
    #8 0x5257d6 in LLVMFuzzerTestOneInput /src/re2/re2/fuzzing/re2_fuzzer.cc:85:3
    #9 0x45aa71 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerLoop.cpp:556:15
    #10 0x45a1b5 in fuzzer::Fuzzer::RunOne(unsigned char const*, unsigned long, bool, fuzzer::InputInfo*, bool*) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerLoop.cpp:470:3
    #11 0x45c77a in fuzzer::Fuzzer::ReadAndExecuteSeedCorpora(std::__Fuzzer::vector<fuzzer::SizedFile, fuzzer::fuzzer_allocator<fuzzer::SizedFile> >&) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerLoop.cpp:748:5
    #12 0x45ca09 in fuzzer::Fuzzer::Loop(std::__Fuzzer::vector<fuzzer::SizedFile, fuzzer::fuzzer_allocator<fuzzer::SizedFile> >&) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerLoop.cpp:794:3
    #13 0x44bcde in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerDriver.cpp:826:6
    #14 0x4744b2 in main /src/llvm-project/compiler-rt/lib/fuzzer/FuzzerMain.cpp:19:10
    #15 0x7f972438b82f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)

SUMMARY: MemorySanitizer: use-of-uninitialized-value /src/re2/./util/sparse_set.h:134:52 in contains
Unique heap origins: 60
Stack depot allocated bytes: 7224
Unique origin histories: 8
History depot allocated bytes: 192
Exiting
MS: 0 ; base unit: 0000000000000000000000000000000000000000
0xa,
\x0a
artifact_prefix='./'; Test unit written to ./crash-adc83b19e793491b1c6ea0fd8b46cd9f32e592fc
Base64: Cg==