[libFuzzer] fix a bug when running a single unit of N bytes with -max_len=M, M<N, caused a buffer overflow

llvm-svn: 280098
diff --git a/llvm/lib/Fuzzer/test/fuzzer-singleinputs.test b/llvm/lib/Fuzzer/test/fuzzer-singleinputs.test
index 3e34273..ca8403b 100644
--- a/llvm/lib/Fuzzer/test/fuzzer-singleinputs.test
+++ b/llvm/lib/Fuzzer/test/fuzzer-singleinputs.test
@@ -5,7 +5,8 @@
 RUN: mkdir -p  %tmp/SINGLE_INPUTS
 RUN: echo aaa > %tmp/SINGLE_INPUTS/aaa
 RUN: echo bbb > %tmp/SINGLE_INPUTS/bbb
-RUN: LLVMFuzzer-SimpleTest %tmp/SINGLE_INPUTS/aaa %tmp/SINGLE_INPUTS/bbb 2>&1 | FileCheck %s --check-prefix=SINGLE_INPUTS
+RUN: LLVMFuzzer-SimpleTest            %tmp/SINGLE_INPUTS/aaa %tmp/SINGLE_INPUTS/bbb 2>&1 | FileCheck %s --check-prefix=SINGLE_INPUTS
+RUN: LLVMFuzzer-SimpleTest -max_len=2 %tmp/SINGLE_INPUTS/aaa %tmp/SINGLE_INPUTS/bbb 2>&1 | FileCheck %s --check-prefix=SINGLE_INPUTS
 RUN: rm -rf  %tmp/SINGLE_INPUTS
 SINGLE_INPUTS: LLVMFuzzer-SimpleTest: Running 2 inputs 1 time(s) each.
 SINGLE_INPUTS: aaa in