[C++] NULL terminate the buffer of files
diff --git a/parser.cc b/parser.cc
index fff3a7d..4b4012e 100644
--- a/parser.cc
+++ b/parser.cc
@@ -529,7 +529,7 @@
 
 void Parse(Makefile* mk) {
   COLLECT_STATS("parse file time");
-  Parser parser(StringPiece(mk->buf(), mk->len()),
+  Parser parser(StringPiece(mk->buf()),
                 mk->filename().c_str(),
                 mk->mutable_stmts());
   parser.Parse();