The file was overwritten when transferring a file that already existed in the downloads folder. With this change we now add " (x)", where x is an incrementing number, starting at 1, using the next non-existing number, to the file name, just before the first dot, or at the end if no dot. This has been applied to the GetDownloadPath method in the platform api.

PiperOrigin-RevId: 457530287

internal/platform/implementation/windows/platform.cc

@@ -49,8 +49,10 @@
 namespace location {
 namespace nearby {
 namespace api {
-std::string ImplementationPlatform::GetDownloadPath(std::string& parent_folder,
-                                                    std::string& file_name) {
+
+namespace {
+std::string GetDownloadPathInternal(std::string& parent_folder,
+                                    std::string& file_name) {
   PWSTR basePath;
 
   // Retrieves the full path of a known folder identified by the folder's
@@ -69,9 +71,10 @@ std::string ImplementationPlatform::GetDownloadPath(std::string& parent_folder,
                    // SHGetKnownFolderPath succeeds or not.
   size_t bufferSize;
   wcstombs_s(&bufferSize, NULL, 0, basePath, 0);
-  std::string fullpathUTF8(bufferSize, '\0');
+  std::string fullpathUTF8(bufferSize - 1, '\0');
   wcstombs_s(&bufferSize, fullpathUTF8.data(), bufferSize, basePath, _TRUNCATE);
-  std::string fullPath = fullpathUTF8;
+
+  std::replace(fullpathUTF8.begin(), fullpathUTF8.end(), '\\', '/');
 
   // If parent_folder starts with a \\ or /, then strip it
   while (!parent_folder.empty() &&
@@ -102,25 +105,74 @@ std::string ImplementationPlatform::GetDownloadPath(std::string& parent_folder,
   std::stringstream path("");
 
   if (parent_folder.empty() && file_name.empty()) {
-    return fullPath;
+    return fullpathUTF8;
   }
   if (parent_folder.empty()) {
-    path << fullPath.c_str() << "\\" << file_name.c_str();
+    path << fullpathUTF8.c_str() << "/" << file_name.c_str();
     std::string retVal = path.str();
     return retVal;
   }
   if (file_name.empty()) {
-    path << fullPath.c_str() << "\\" << parent_folder.c_str();
+    path << fullpathUTF8.c_str() << "/" << parent_folder.c_str();
     std::string retVal = path.str();
     return retVal;
   }
 
-  path << fullPath.c_str() << "\\" << parent_folder.c_str() << "\\"
+  path << fullpathUTF8.c_str() << "/" << parent_folder.c_str() << "/"
        << file_name.c_str();
   std::string retVal = path.str();
   return retVal;
 }
 
+// If the file already exists we add " (x)", where x is an incrementing number,
+// starting at 1, using the next non-existing number, to the file name, just
+// before the first dot, or at the end if no dot. The absolute path is returned.
+std::string CreateOutputFileWithRename(absl::string_view path) {
+  auto last_separator = path.find_last_of('/');
+  std::string folder(path.substr(0, last_separator));
+  std::string file_name(path.substr(last_separator));
+
+  int count = 0;
+
+  // Locate the first dot
+  auto first = file_name.find_first_of('.', 0);
+
+  if (first == std::string::npos) {
+    first = file_name.size();
+  }
+
+  // Break the string at the dot.
+  auto file_name1 = file_name.substr(0, first);
+  auto file_name2 = file_name.substr(first);
+
+  // Construct the target file name
+  std::string target(path);
+
+  std::fstream file;
+  file.open(target, std::fstream::binary | std::fstream::in);
+
+  // While we successfully open the file, keep incrementing the count.
+  while (!(file.rdstate() & std::ifstream::failbit)) {
+    file.close();
+    target = absl::StrCat(folder, file_name1, " (", ++count, ")", file_name2);
+    file.clear();
+    file.open(target, std::fstream::binary | std::fstream::in);
+  }
+
+  // The above leaves the file open, so close it.
+  file.close();
+
+  return target;
+}
+
+}  // namespace
+
+std::string ImplementationPlatform::GetDownloadPath(std::string& parent_folder,
+                                                    std::string& file_name) {
+  return CreateOutputFileWithRename(
+      GetDownloadPathInternal(parent_folder, file_name));
+}
+
 OSName ImplementationPlatform::GetCurrentOS() { return OSName::kWindows; }
 
 std::unique_ptr<AtomicBoolean> ImplementationPlatform::CreateAtomicBoolean(