[libFuzzer] make -test_single_input more reliable: make sure the input's size is equal to it's capacity

llvm-svn: 251961

1 files changed, 3 insertions, 1 deletions

diff --git a/llvm/lib/Fuzzer/FuzzerDriver.cpp b/llvm/lib/Fuzzer/FuzzerDriver.cpp
index 821d34cccc2..363abc482cb 100644
--- a/llvm/lib/Fuzzer/FuzzerDriver.cpp
+++ b/llvm/lib/Fuzzer/FuzzerDriver.cpp
@@ -184,7 +184,9 @@ static int RunInMultipleProcesses(const std::vector<std::string> &Args,
 
 int RunOneTest(Fuzzer *F, const char *InputFilePath) {
   Unit U = FileToVector(InputFilePath);
-  F->ExecuteCallback(U);
+  Unit PreciseSizedU(U);
+  assert(PreciseSizedU.size() == PreciseSizedU.capacity());
+  F->ExecuteCallback(PreciseSizedU);
   return 0;
 }