fixed off-by-one in parser

src/idl_parser.cpp

@@ -492,7 +492,7 @@ CheckedError Parser::Next() {
         if (has_sign) {
           // Check for +/-inf which is considered a float constant.
           if (strncmp(cursor_, "inf", 3) == 0 &&
-              !(IsIdentifierStart(cursor_[4]) || is_digit(cursor_[4]))) {
+              !(IsIdentifierStart(cursor_[3]) || is_digit(cursor_[3]))) {
             attribute_.assign(cursor_ - 1, cursor_ + 3);
             token_ = kTokenFloatConstant;
             cursor_ += 3;

tests/fuzzer/readme.md

@@ -11,6 +11,7 @@ For details about **libFuzzer** see: https://llvm.org/docs/LibFuzzer.html
 To build and run these tests LLVM compiler (with clang frontend) and CMake should be installed before.
 
 The fuzzer section include four tests:
+- `annotator_fuzzer` checks that inputs given to the flatc --annotate are always parsable;
 - `verifier_fuzzer` checks stability of deserialization engine for `Monster` schema;
 - `parser_fuzzer` checks stability of schema and json parser under various inputs;
 - `scalar_parser` focused on validation of the parser while parse numeric scalars in schema and/or json files;