[libFuzzer] make -test_single_input more reliable: make sure the inpu…

…t's size is equal to it's capacity

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251961 91177308-0d34-0410-b5e6-96231b3b80d8

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;
 }