Make dgo unpacker work on pal dgos with wrong size (#714)

* make dgo unpacker work on pal dgos with wrong size

* format string

common/util/DgoReader.cpp

@@ -16,7 +16,17 @@ DgoReader::DgoReader(std::string file_name, const std::vector<u8>& data)
 
   // get all obj files...
   for (uint32_t i = 0; i < header.object_count; i++) {
-    auto obj_header = reader.read<ObjectHeader>();
+    ObjectHeader obj_header = reader.read<ObjectHeader>();
+
+    if (reader.bytes_left() < obj_header.size && i == header.object_count - 1 &&
+        obj_header.size - reader.bytes_left() <= 48) {
+      printf(
+          "Warning: final file %s in DGO %s has a size missing %d bytes.  It will be adjusted from "
+          "%d to %d bytes.\n",
+          obj_header.name, header.name, obj_header.size - reader.bytes_left(), obj_header.size,
+          (int)reader.bytes_left());
+      obj_header.size = reader.bytes_left();
+    }
     assert(reader.bytes_left() >= obj_header.size);
     assert_string_empty_after(obj_header.name, 60);
 

common/util/FileUtil.cpp

@@ -15,6 +15,7 @@
 #include "BinaryWriter.h"
 #include "common/common_types.h"
 #include "third-party/svpng.h"
+#include "third-party/fmt/core.h"
 #include "third-party/lzokay/lzokay.hpp"
 
 #ifdef _WIN32
@@ -119,6 +120,21 @@ void write_text_file(const std::string& file_name, const std::string& text) {
 }
 
 std::vector<uint8_t> read_binary_file(const std::string& filename) {
+  // make sure file exists and isn't a directory
+  std::filesystem::path path(filename);
+
+  auto status = std::filesystem::status(std::filesystem::path(filename));
+
+  if (!std::filesystem::exists(status)) {
+    throw std::runtime_error(fmt::format("File {} cannot be opened: does not exist.", filename));
+  }
+
+  if (status.type() != std::filesystem::file_type::regular &&
+      status.type() != std::filesystem::file_type::symlink) {
+    throw std::runtime_error(
+        fmt::format("File {} cannot be opened: not a regular file or symlink.", filename));
+  }
+
   auto fp = fopen(filename.c_str(), "rb");
   if (!fp)
     throw std::runtime_error("File " + filename +

tools/dgo_unpacker.cpp

@@ -1,9 +1,11 @@
 #include <cstdio>
+#include <stdexcept>
 #include "common/versions.h"
 #include "common/util/FileUtil.h"
 #include "common/util/DgoReader.h"
 
-int main(int argc, char** argv) {
+namespace {
+int run(int argc, char** argv) {
   printf("OpenGOAL version %d.%d\n", versions::GOAL_VERSION_MAJOR, versions::GOAL_VERSION_MINOR);
   printf("DGO Unpacking Tool\n");
 
@@ -42,3 +44,13 @@ int main(int argc, char** argv) {
   printf("Done\n");
   return 0;
 }
+}  // namespace
+
+int main(int argc, char** argv) {
+  try {
+    return run(argc, argv);
+  } catch (const std::exception& e) {
+    printf("An error occurred: %s\n", e.what());
+    return 1;
+  }
+}