annotate contrib/fuzz/bdiff.cc @ 50329:3dbc7b1ecaba stable

typing: correct the signature of error.CommandError

There's a place in `mercurial.dispatch._parse()` that passes None if a parse
error happens before the command can be parsed out, and casting the error to
bytes works fine because the command and message fields are apparently ignored.
Likewise, TortoiseHg similarly passes None for the same reason.

/*
 * bdiff.cc - fuzzer harness for bdiff.c
 *
 * Copyright 2018, Google Inc.
 *
 * This software may be used and distributed according to the terms of
 * the GNU General Public License, incorporated herein by reference.
 */
#include <memory>
#include <stdlib.h>

#include "FuzzedDataProvider.h"

extern "C" {
#include "bdiff.h"

extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)
{
	return 0;
}

int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
	FuzzedDataProvider provider(Data, Size);
	std::string left = provider.ConsumeRandomLengthString(Size);
	std::string right = provider.ConsumeRemainingBytesAsString();

	struct bdiff_line *a, *b;
	int an = bdiff_splitlines(left.c_str(), left.size(), &a);
	int bn = bdiff_splitlines(right.c_str(), right.size(), &b);
	struct bdiff_hunk l;
	bdiff_diff(a, an, b, bn, &l);
	free(a);
	free(b);
	bdiff_freehunks(l.next);
	return 0; // Non-zero return values are reserved for future use.
}

} // extern "C"