diff -r 55db747a21ad -r 8c692a6b5ad1 contrib/fuzz/manifest.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/fuzz/manifest.cc	Thu Sep 06 02:36:25 2018 -0400
@@ -0,0 +1,75 @@
+#include <Python.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <string>
+
+extern "C" {
+
+/* TODO: use Python 3 for this fuzzing? */
+PyMODINIT_FUNC initparsers(void);
+
+static char cpypath[8192] = "\0";
+
+extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)
+{
+	const std::string subdir = "/sanpy/lib/python2.7";
+	/* HACK ALERT: we need a full Python installation built without
+	   pymalloc and with ASAN, so we dump one in
+	   $OUT/sanpy/lib/python2.7. This helps us wire that up. */
+	std::string selfpath(*argv[0]);
+	std::string pypath;
+	auto pos = selfpath.rfind("/");
+	if (pos == std::string::npos) {
+		char wd[8192];
+		getcwd(wd, 8192);
+		pypath = std::string(wd) + subdir;
+	} else {
+		pypath = selfpath.substr(0, pos) + subdir;
+	}
+	strncpy(cpypath, pypath.c_str(), pypath.size());
+	setenv("PYTHONPATH", cpypath, 1);
+	Py_SetPythonHome(cpypath);
+	return 0;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
+{
+	Py_InitializeEx(0);
+	initparsers();
+	PyObject *mtext =
+	    PyBytes_FromStringAndSize((const char *)Data, (Py_ssize_t)Size);
+	PyObject *mainmod = PyImport_AddModule("__main__");
+	PyObject *globals = PyModule_GetDict(mainmod);
+	PyObject *locals = PyDict_New();
+	PyDict_SetItemString(locals, "mdata", mtext);
+	PyCodeObject *code =
+	    (PyCodeObject *)Py_CompileString(R"py(
+from parsers import lazymanifest
+lm = lazymanifest(mdata)
+try:
+  # iterate the whole thing, which causes the code to fully parse
+  # every line in the manifest
+  list(lm.iterentries())
+  lm[b'xyzzy'] = (b'\0' * 20, 'x')
+  # do an insert, text should change
+  assert lm.text() != mdata, "insert should change text and didn't: %r %r" % (lm.text(), mdata)
+  del lm[b'xyzzy']
+  # should be back to the same
+  assert lm.text() == mdata, "delete should have restored text but didn't: %r %r" % (lm.text(), mdata)
+except Exception as e:
+  pass
+  # uncomment this print if you're editing this Python code
+  # to debug failures.
+  # print e
+)py",
+	                                     "fuzzer", Py_file_input);
+	PyEval_EvalCode(code, globals, locals);
+	Py_DECREF(code);
+	Py_DECREF(locals);
+	Py_DECREF(mtext);
+	Py_Finalize();
+	return 0; // Non-zero return values are reserved for future use.
+}
+}