Skip to content

IsFileWriteable: probe via permission bits, not append-open #20

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
willwade merged 1 commit into from
Jun 18, 2026
Merged

IsFileWriteable: probe via permission bits, not append-open #20

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions src/DasherCore/FileUtils.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -17,8 +17,16 @@ void FileUtils::SetDataDirectory(const std::string& dataDir) {
} // namespace Dasher

static bool IsFileWriteable(const std::filesystem::path& file_path) {
std::fstream file(file_path.string(), std::ios_base::app | std::fstream::out);
return file.is_open();
// Check writability via permission bits without opening the file.
// Opening with ios_base::app|out (the previous implementation) attempted
// to create/append the file just to test writability, which generated
// sandbox deny storms against read-only bundled data on iOS keyboard
// extensions and could accidentally create empty files on other platforms.
std::error_code ec;
const auto status = std::filesystem::status(file_path, ec);
if (ec) return false;
using P = std::filesystem::perms;
return (status.permissions() & (P::owner_write | P::group_write | P::others_write)) != P::none;
}

int Dasher::FileUtils::GetFileSize(const std::string& strFileName) {
Expand Down
Loading