Handle Filesystem Errors When Finishing a Model Import Download

Choosing the final name and moving the downloaded project into place
could throw from inside the download callback. Any such error now removes
the temporary file and reports the existing import failure message.

src/libslic3r/Utils.hpp

@@ -285,6 +285,21 @@ inline std::string sanitize_filename(const std::string &filename){
     const std::regex special_chars("[/\\\\:*?\"<>|]");
     return std::regex_replace(filename, special_chars, "_");
 }
+// Reduce an untrusted, possibly path-qualified name to a single sanitized file name.
+// Returns an empty string when nothing usable remains.
+inline std::string sanitize_file_basename(const std::string &name){
+    const size_t sep = name.find_last_of("/\\");
+    const std::string base = sanitize_filename(sep == std::string::npos ? name : name.substr(sep + 1));
+    // Names made only of dots and spaces refer to the folder or its parent, or are stripped to nothing on Windows.
+    return base.find_first_not_of(". ") == std::string::npos ? std::string() : base;
+}
+// Marker file a download of this process writes to before it is renamed to filename.
+boost::filesystem::path download_marker_path(const boost::filesystem::path &dest_folder, const std::string &filename);
+// Finds a sanitized variant of filename, "name(N).ext" if needed, that neither an entry of dest_folder
+// nor the download marker of another download uses. The marker at ignored_marker does not count.
+// Returns true and the name in result, or false and the last name tried.
+bool find_unused_filename(const boost::filesystem::path &dest_folder, const std::string &filename,
+                          const boost::filesystem::path &ignored_marker, std::string &result);
 // File path / name / extension splitting utilities, working with UTF-8,
 // to be published to Perl.
 namespace PerlUtils {

src/libslic3r/utils.cpp

@@ -1321,6 +1321,31 @@ unsigned get_current_pid()
 #endif
 }
 
+boost::filesystem::path download_marker_path(const boost::filesystem::path &dest_folder, const std::string &filename)
+{
+    return dest_folder / (filename + "." + std::to_string(get_current_pid()) + ".download");
+}
+
+bool find_unused_filename(const boost::filesystem::path &dest_folder, const std::string &filename,
+                          const boost::filesystem::path &ignored_marker, std::string &result)
+{
+    // Probe the name that will be written, so a name the sanitizing maps onto an existing file is versioned too.
+    const std::string sanitized = sanitize_filename(filename);
+    const std::string extension = boost::filesystem::path(sanitized).extension().string();
+    const std::string stem      = sanitized.substr(0, sanitized.size() - extension.size());
+    auto is_used = [&](const std::string &name) {
+        const boost::filesystem::path marker = download_marker_path(dest_folder, name);
+        return boost::filesystem::exists(dest_folder / name) || (marker != ignored_marker && boost::filesystem::exists(marker));
+    };
+    result = sanitized;
+    for (size_t version = 1; is_used(result); ++version) {
+        if (version > 999)
+            return false;
+        result = stem + "(" + std::to_string(version) + ")" + extension;
+    }
+    return true;
+}
+
 std::string per_user_temp_id()
 {
 #ifdef WIN32

src/slic3r/GUI/DownloaderFileGet.cpp

@@ -71,17 +71,6 @@ bool FileGet::is_subdomain(const std::string& url, const std::string& domain)
 	return false;
 }
 
-namespace {
-unsigned get_current_pid()
-{
-#ifdef WIN32
-	return GetCurrentProcessId();
-#else
-	return ::getpid();
-#endif
-}
-}
-
 // int = DOWNLOAD ID; string = file path
 wxDEFINE_EVENT(EVT_DWNLDR_FILE_COMPLETE, wxCommandEvent);
 // int = DOWNLOAD ID; string = error msg
@@ -144,25 +133,10 @@ void FileGet::priv::get_perform()
 	std::string extension;
 	if (m_written == 0)
 	{
-		boost::filesystem::path dest_path = m_dest_folder / m_filename;
-		extension = dest_path.extension().string();
-		std::string just_filename = m_filename.substr(0, m_filename.size() - extension.size());
-		std::string final_filename = just_filename;
-        // Find unsed filename 
+		std::string final_filename;
+		bool found = false;
 		try {
-			size_t version = 0;
-			while (boost::filesystem::exists(m_dest_folder / (final_filename + extension)) || boost::filesystem::exists(m_dest_folder / (final_filename + extension + "." + std::to_string(get_current_pid()) + ".download")))
-			{
-				++version;
-				if (version > 999) {
-					wxCommandEvent* evt = new wxCommandEvent(EVT_DWNLDR_FILE_ERROR);
-					evt->SetString(GUI::format_wxstr(L"Failed to find suitable filename. Last name: %1%." , (m_dest_folder / (final_filename + extension)).string()));
-					evt->SetInt(m_id);
-					m_evt_handler->QueueEvent(evt);
-					return;
-				}
-				final_filename = GUI::format("%1%(%2%)", just_filename, std::to_string(version));
-			}
+			found = find_unused_filename(m_dest_folder, m_filename, m_tmp_path, final_filename);
 		} catch (const boost::filesystem::filesystem_error& e)
 		{
 			wxCommandEvent* evt = new wxCommandEvent(EVT_DWNLDR_FILE_ERROR);
@@ -171,10 +145,18 @@ void FileGet::priv::get_perform()
 			m_evt_handler->QueueEvent(evt);
 			return;
 		}
+		if (!found) {
+			wxCommandEvent* evt = new wxCommandEvent(EVT_DWNLDR_FILE_ERROR);
+			evt->SetString(GUI::format_wxstr(L"Failed to find suitable filename. Last name: %1%." , (m_dest_folder / final_filename).string()));
+			evt->SetInt(m_id);
+			m_evt_handler->QueueEvent(evt);
+			return;
+		}
 
-        m_filename = sanitize_filename(final_filename + extension);
+        m_filename = final_filename;
+		extension = boost::filesystem::path(m_filename).extension().string();
 
-        m_tmp_path = m_dest_folder / (m_filename + "." + std::to_string(get_current_pid()) + ".download");
+        m_tmp_path = download_marker_path(m_dest_folder, m_filename);
 
 		wxCommandEvent* evt = new wxCommandEvent(EVT_DWNLDR_FILE_NAME_CHANGE);
 		evt->SetString(boost::nowide::widen(m_filename));
@@ -221,7 +203,32 @@ void FileGet::priv::get_perform()
 			if(dest_path.empty()) {
 				std::string filename = extract_remote_filename(header);
 				if (!filename.empty()) {
-					m_filename = filename;
+					// The name comes from the server: keep it inside the destination folder and never
+					// replace an existing file. Keep the current name if nothing usable remains.
+					filename = sanitize_file_basename(filename);
+					std::string unused;
+					try {
+						if (filename.empty() || !find_unused_filename(m_dest_folder, filename, m_tmp_path, unused))
+							unused.clear();
+					} catch (const boost::filesystem::filesystem_error&) {
+						unused.clear();
+					}
+					const boost::filesystem::path tmp_path = unused.empty() ? m_tmp_path : download_marker_path(m_dest_folder, unused);
+					if (tmp_path != m_tmp_path) {
+						// Move the marker to the adopted name so that other downloads see the name as taken.
+						// Only before anything is written, so that no downloaded data has to be carried over.
+						FILE* tmp_file = m_written == 0 ? fopen(wxString(tmp_path.wstring()).c_str(), "wb") : nullptr;
+						if (tmp_file != nullptr) {
+							fclose(file);
+							boost::system::error_code ec;
+							boost::filesystem::remove(m_tmp_path, ec);
+							file = tmp_file;
+							m_tmp_path = tmp_path;
+						} else
+							unused.clear();
+					}
+					if (!unused.empty())
+						m_filename = unused;
 					dest_path = m_dest_folder / m_filename;
 					wxCommandEvent* evt = new wxCommandEvent(EVT_DWNLDR_FILE_NAME_CHANGE);
 					evt->SetString(boost::nowide::widen(m_filename));
@@ -327,6 +334,18 @@ void FileGet::priv::get_perform()
                     m_evt_handler->QueueEvent(evt);
                 }
 				fclose(file);
+				// Another file may have taken the name while downloading.
+				if (!dest_path.empty() && boost::filesystem::exists(dest_path)) {
+					std::string unused;
+					if (!find_unused_filename(m_dest_folder, m_filename, m_tmp_path, unused))
+						throw std::runtime_error("No unused file name.");
+					m_filename = unused;
+					dest_path = m_dest_folder / m_filename;
+					wxCommandEvent* evt = new wxCommandEvent(EVT_DWNLDR_FILE_NAME_CHANGE);
+					evt->SetString(boost::nowide::widen(m_filename));
+					evt->SetInt(m_id);
+					m_evt_handler->QueueEvent(evt);
+				}
 				boost::filesystem::rename(m_tmp_path, dest_path);
 			}
 			catch (const std::exception& /*e*/)

src/slic3r/GUI/Plater.cpp

@@ -15681,6 +15681,11 @@ void Plater::import_model_id(wxString download_info)
         //wxString sError = error.what();
     }
 
+    // The name comes from the link: reduce it to a plain file name inside the download folder.
+    filename = from_u8(sanitize_file_basename(into_u8(filename)));
+    if (filename.empty())
+        filename = "untitled.3mf";
+
     bool download_ok = false;
     int retry_count = 0;
     const int max_retries = 3;
@@ -15722,51 +15727,28 @@ void Plater::import_model_id(wxString download_info)
 
         msg = _L("Preparing 3MF file...");
 
-        //gets the number of files with the same name
-        std::vector<wxString>   vecFiles;
-        bool                    is_already_exist = false;
-
-
         target_path = fs::path(wxGetApp().app_config->get("download_path"));
 
-        try
-        {
-            vecFiles.clear();
-            wxString extension = fs::path(filename.wx_str()).extension().c_str();
-
-
-            //check file suffix
-            if (!extension.Contains(".3mf")) {
-                msg = _L("Download failed; unknown file format.");
-                return;
-            }
-
-            auto name = filename.substr(0, filename.length() - extension.length() - 1);
-
-            for (const auto& iter : boost::filesystem::directory_iterator(target_path))
-            {
-                if (boost::filesystem::is_directory(iter.path()))
-                    continue;
-
-                wxString sFile = iter.path().filename().string().c_str();
-                if (strstr(sFile.c_str(), name.c_str()) != NULL) {
-                    vecFiles.push_back(sFile);
-                }
-
-                if (sFile == filename) is_already_exist = true;
-            }
-        }
-        catch (const std::exception&)
-        {
-            //wxString sError = error.what();
+        //check file suffix
+        wxString extension = fs::path(filename.wx_str()).extension().c_str();
+        if (!extension.Contains(".3mf")) {
+            msg = _L("Download failed; unknown file format.");
+            return;
         }
 
-        //update filename
-        if (is_already_exist && vecFiles.size() >= 1) {
-            wxString extension = fs::path(filename.wx_str()).extension().c_str();
-            wxString name = filename.substr(0, filename.length() - extension.length());
-            filename = wxString::Format("%s(%d)%s", name, vecFiles.size() + 1, extension).ToStdString();
+        //never replace an existing file
+        std::string unused_filename;
+        try {
+            if (!find_unused_filename(target_path, into_u8(filename), {}, unused_filename))
+                unused_filename.clear();
+        } catch (const std::exception&) {
+            unused_filename.clear();
         }
+        if (unused_filename.empty()) {
+            msg = _L("Importing to Orca Slicer failed. Please download the file and manually import it.");
+            return;
+        }
+        filename = from_u8(unused_filename);
 
 
         msg = _L("Downloading project...");
@@ -15778,10 +15760,6 @@ void Plater::import_model_id(wxString download_info)
         boost::uuids::uuid uuid = boost::uuids::random_generator()();
         std::string unique = to_string(uuid).substr(0, 6);
 
-        if (filename.empty()) {
-            filename = "untitled.3mf";
-        }
-
         //target_path /= (boost::format("%1%_%2%.3mf") % filename % unique).str();
         target_path /= fs::path(filename.wc_str());
 
@@ -15830,13 +15808,26 @@ void Plater::import_model_id(wxString download_info)
                         cont = false;
                     }
                 })
-                .on_complete([&cont, &download_ok, tmp_path, target_path](std::string body, unsigned /* http_status */) {
+                .on_complete([&cont, &download_ok, &msg, tmp_path, &target_path](std::string body, unsigned /* http_status */) {
                         fs::fstream file(tmp_path, std::ios::out | std::ios::binary | std::ios::trunc);
                         file.write(body.c_str(), body.size());
                         file.close();
-                        fs::rename(tmp_path, target_path);
                         cont = false;
-                        download_ok = true;
+                        try {
+                            // Another file may have taken the name while downloading.
+                            std::string unused_filename;
+                            if (find_unused_filename(target_path.parent_path(), target_path.filename().string(), {}, unused_filename)) {
+                                target_path = target_path.parent_path() / unused_filename;
+                                fs::rename(tmp_path, target_path);
+                                download_ok = true;
+                                return;
+                            }
+                        } catch (const std::exception &e) {
+                            BOOST_LOG_TRIVIAL(error) << "import_model_id: failed to move the download into place: " << e.what();
+                        }
+                        boost::system::error_code ec;
+                        fs::remove(tmp_path, ec);
+                        msg = _L("Importing to Orca Slicer failed. Please download the file and manually import it.");
                 }).perform_sync();
 
                 // for break while

tests/libslic3r/test_utils.cpp

@@ -152,3 +152,94 @@ TEST_CASE("resolve_cli_input_path leaves inputs that must not be completed uncha
         REQUIRE(resolve_cli_input_path("").empty());
     }
 }
+
+TEST_CASE("sanitize_file_basename keeps only a plain file name from an untrusted name", "[Utils]") {
+    const std::string unicode = "\xe6\xa8\xa1\xe5\x9e\x8b \xc3\xa9t\xc3\xa9.3mf"; // UTF-8 CJK and accented Latin
+    const auto [input, expected] = GENERATE_COPY(table<std::string, std::string>({
+        {"normal.3mf", "normal.3mf"},
+        {"../../x.3mf", "x.3mf"},
+        {"..\\..\\x.3mf", "x.3mf"},
+        {"C:\\x.3mf", "x.3mf"},
+        {"C:x.3mf", "C_x.3mf"},
+        {"/etc/x", "x"},
+        {"a/b\\c.gcode", "c.gcode"},
+        {"x:stream", "x_stream"}, // no NTFS alternate data stream
+        {"x.", "x."},
+        {".3mf", ".3mf"},
+        {unicode, unicode},
+    }));
+    CAPTURE(input);
+    CHECK(sanitize_file_basename(input) == expected);
+}
+
+TEST_CASE("sanitize_file_basename rejects names that do not name a file", "[Utils]") {
+    const std::string input = GENERATE(as<std::string>{}, "", ".", "..", "../..", "dir/", "..\\", " ", ". .", "...");
+    CAPTURE(input);
+    CHECK(sanitize_file_basename(input).empty());
+}
+
+namespace {
+void touch(const boost::filesystem::path &path) { std::ofstream(path.string()) << "existing"; }
+std::string file_contents(const boost::filesystem::path &path)
+{
+    std::ifstream file(path.string());
+    return std::string(std::istreambuf_iterator<char>(file), std::istreambuf_iterator<char>());
+}
+} // namespace
+
+TEST_CASE("find_unused_filename keeps a name nothing uses", "[Utils]") {
+    ScopedTemporaryDir dir;
+    std::string name;
+    REQUIRE(find_unused_filename(dir.path(), "model.3mf", {}, name));
+    CHECK(name == "model.3mf");
+}
+
+TEST_CASE("find_unused_filename versions a name an existing file uses", "[Utils]") {
+    ScopedTemporaryDir dir;
+    touch(dir.path() / "model.3mf");
+    std::string name;
+    REQUIRE(find_unused_filename(dir.path(), "model.3mf", {}, name));
+    CHECK(name == "model(1).3mf");
+}
+
+TEST_CASE("find_unused_filename versions a name that maps onto an existing file once sanitized", "[Utils]") {
+    ScopedTemporaryDir dir;
+    touch(dir.path() / "my_model.3mf");
+    const std::string input = GENERATE(as<std::string>{}, "my?model.3mf", "my:model.3mf", "my*model.3mf");
+    CAPTURE(input);
+    std::string name;
+    REQUIRE(find_unused_filename(dir.path(), input, {}, name));
+    CHECK(name == "my_model(1).3mf");
+    CHECK(file_contents(dir.path() / "my_model.3mf") == "existing");
+}
+
+TEST_CASE("find_unused_filename treats the marker of another download as used", "[Utils]") {
+    ScopedTemporaryDir dir;
+    touch(download_marker_path(dir.path(), "model.3mf"));
+    std::string name;
+    REQUIRE(find_unused_filename(dir.path(), "model.3mf", {}, name));
+    CHECK(name == "model(1).3mf");
+}
+
+TEST_CASE("find_unused_filename ignores the marker of the download asking", "[Utils]") {
+    ScopedTemporaryDir dir;
+    const boost::filesystem::path own_marker = download_marker_path(dir.path(), "model.3mf");
+    touch(own_marker);
+    std::string name;
+    REQUIRE(find_unused_filename(dir.path(), "model.3mf", own_marker, name));
+    CHECK(name == "model.3mf");
+}
+
+TEST_CASE("find_unused_filename gives up after 999 versions", "[Utils]") {
+    ScopedTemporaryDir dir;
+    touch(dir.path() / "model.3mf");
+    for (int version = 1; version < 999; ++version)
+        touch(dir.path() / ("model(" + std::to_string(version) + ").3mf"));
+    std::string name;
+    REQUIRE(find_unused_filename(dir.path(), "model.3mf", {}, name));
+    CHECK(name == "model(999).3mf");
+
+    touch(dir.path() / name);
+    REQUIRE_FALSE(find_unused_filename(dir.path(), "model.3mf", {}, name));
+    CHECK(name == "model(999).3mf");
+}