Handle FileNotFoundError on download of messages

securedrop/journalist_app/col.py

@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
 
+from pathlib import Path
+
 from flask import (
     Blueprint,
     abort,
@@ -93,6 +95,18 @@ def download_single_file(filesystem_id: str, fn: str) -> werkzeug.Response:
         if '..' in fn or fn.startswith('/'):
             abort(404)
 
+        file = current_app.storage.path(filesystem_id, fn)
+        if not Path(file).is_file():
+            flash(
+                gettext(
+                    "Your download failed because a file could not be found. An admin can find "
+                    + "more information in the system and monitoring logs."
+                ),
+                "error"
+            )
+            current_app.logger.error("File {} not found".format(file))
+            return redirect(url_for("col.col", filesystem_id=filesystem_id))
+
         # mark as seen by the current user
         try:
             journalist = g.get("user")

securedrop/journalist_app/utils.py

@@ -3,6 +3,7 @@
 import datetime
 import os
 from typing import Optional, List, Union, Any
+from urllib.parse import urlparse
 
 import flask
 import werkzeug
@@ -190,7 +191,7 @@ def mark_seen(targets: List[Union[Submission, Reply]], user: Journalist) -> None
             raise
 
 
-def download(zip_basename: str, submissions: List[Union[Submission, Reply]]) -> flask.Response:
+def download(zip_basename: str, submissions: List[Union[Submission, Reply]]) -> werkzeug.Response:
     """Send client contents of ZIP-file *zip_basename*-<timestamp>.zip
     containing *submissions*. The ZIP-file, being a
     :class:`tempfile.NamedTemporaryFile`, is stored on disk only
@@ -201,7 +202,19 @@ def download(zip_basename: str, submissions: List[Union[Submission, Reply]]) ->
     :param list submissions: A list of :class:`models.Submission`s to
                              include in the ZIP-file.
     """
-    zf = current_app.storage.get_bulk_archive(submissions, zip_directory=zip_basename)
+    try:
+        zf = current_app.storage.get_bulk_archive(submissions, zip_directory=zip_basename)
+    except FileNotFoundError:
+        flash(
+            gettext(
+                "Your download failed because a file could not be found. An admin can find "
+                + "more information in the system and monitoring logs."
+            ),
+            "error"
+        )
+        referrer = urlparse(str(request.referrer)).path
+        return redirect(referrer)
+
     attachment_filename = "{}--{}.zip".format(
         zip_basename, datetime.datetime.utcnow().strftime("%Y-%m-%d--%H-%M-%S")
     )

securedrop/store.py

@@ -201,25 +201,36 @@ def get_bulk_archive(self,
                        for i in selected_submissions])
         # The below nested for-loops are there to create a more usable
         # folder structure per #383
+        missing_files = False
+
         with zipfile.ZipFile(zip_file, 'w') as zip:
             for source in sources:
                 fname = ""
                 submissions = [s for s in selected_submissions
                                if s.source.journalist_designation == source]
                 for submission in submissions:
                     filename = self.path(submission.source.filesystem_id, submission.filename)
-                    document_number = submission.filename.split('-')[0]
-                    if zip_directory == submission.source.journalist_filename:
-                        fname = zip_directory
+
+                    if os.path.exists(filename):
+                        document_number = submission.filename.split('-')[0]
+                        if zip_directory == submission.source.journalist_filename:
+                            fname = zip_directory
+                        else:
+                            fname = os.path.join(zip_directory, source)
+                        zip.write(filename, arcname=os.path.join(
+                            fname,
+                            "%s_%s" % (document_number,
+                                       submission.source.last_updated.date()),
+                            os.path.basename(filename)
+                        ))
                     else:
-                        fname = os.path.join(zip_directory, source)
-                    zip.write(filename, arcname=os.path.join(
-                        fname,
-                        "%s_%s" % (document_number,
-                                   submission.source.last_updated.date()),
-                        os.path.basename(filename)
-                    ))
-        return zip_file
+                        missing_files = True
+                        current_app.logger.error("File {} not found".format(filename))
+
+        if missing_files:
+            raise FileNotFoundError
+        else:
+            return zip_file
 
     def move_to_shredder(self, path: str) -> None:
         """

securedrop/tests/functional/journalist_navigation_steps.py

@@ -753,6 +753,17 @@ def cookie_string_from_selenium_cookies(cookies):
 
         assert self.secret_message == submission
 
+    def _journalist_downloads_message_missing_file(self):
+        self._journalist_selects_the_first_source()
+
+        self.wait_for(lambda: self.driver.find_element_by_css_selector("ul#submissions"))
+
+        submissions = self.driver.find_elements_by_css_selector("#submissions a")
+        assert 1 == len(submissions)
+
+        file_link = submissions[0]
+        file_link.click()
+
     def _journalist_composes_reply(self):
         reply_text = (
             "Thanks for the documents. Can you submit more " "information about the main program?"
@@ -1097,3 +1108,42 @@ def _journalist_uses_js_buttons_to_download_unread(self):
         for checkbox in checkboxes:
             classes = checkbox.get_attribute("class")
             assert "unread-cb" in classes
+
+    def _journalist_sees_missing_file_error_message(self):
+        notification = self.driver.find_element_by_css_selector(".error")
+
+        if self.accept_languages is None:
+            expected_text = (
+                "Your download failed because a file could not be found. An admin can find "
+                + "more information in the system and monitoring logs."
+            )
+            assert expected_text == notification.text
+
+    def _journalist_is_on_collection_page(self):
+        return self.wait_for(
+            lambda: self.driver.find_element_by_css_selector("div.journalist-view-single")
+        )
+
+    def _journalist_clicks_source_unread(self):
+        self.driver.find_element_by_css_selector("span.unread a").click()
+
+    def _journalist_selects_first_source_then_download_all(self):
+        checkboxes = self.driver.find_elements_by_name("cols_selected")
+        assert len(checkboxes) == 1
+        checkboxes[0].click()
+
+        self.driver.find_element_by_xpath("//button[@value='download-all']").click()
+
+    def _journalist_selects_first_source_then_download_unread(self):
+        checkboxes = self.driver.find_elements_by_name("cols_selected")
+        assert len(checkboxes) == 1
+        checkboxes[0].click()
+
+        self.driver.find_element_by_xpath("//button[@value='download-unread']").click()
+
+    def _journalist_selects_message_then_download_selected(self):
+        checkboxes = self.driver.find_elements_by_name("doc_names_selected")
+        assert len(checkboxes) == 1
+        checkboxes[0].click()
+
+        self.driver.find_element_by_xpath("//button[@value='download']").click()

securedrop/tests/functional/test_journalist.py

@@ -15,6 +15,9 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
+from pathlib import Path
+
+import pytest
 
 from . import functional_test as ft
 from . import journalist_navigation_steps
@@ -76,3 +79,76 @@ def test_journalist_interface_ui_with_modal(self):
         self._journalist_selects_the_first_source()
         self._journalist_uses_js_buttons_to_download_unread()
         self._journalist_delete_all_confirmation()
+
+
+class TestJournalistMissingFile(
+    ft.FunctionalTest,
+    source_navigation_steps.SourceNavigationStepsMixin,
+    journalist_navigation_steps.JournalistNavigationStepsMixin
+):
+    """Test error handling when a message file has been deleted from disk but remains in the
+    database. Ref #4787."""
+
+    @pytest.fixture(scope="function")
+    def missing_msg_file(self):
+        """Fixture to setup the message with missing file used in the following tests."""
+        # Submit a message
+        self._source_visits_source_homepage()
+        self._source_chooses_to_submit_documents()
+        self._source_continues_to_submit_page()
+        self._source_submits_a_message()
+        self._source_logs_out()
+
+        # Remove the message file from the store
+        storage_path = Path(self.journalist_app.storage.storage_path)
+        msg_files = [p for p in storage_path.rglob("*") if p.is_file()]
+        assert len(msg_files) == 1
+        msg_files[0].unlink()
+
+        self.switch_to_firefox_driver()
+
+        yield
+
+        self.switch_to_torbrowser_driver()
+
+    def test_download_source_unread(self, missing_msg_file):
+        """Test behavior when the journalist clicks on the source's "n unread" button from the
+        journalist home page."""
+        self._journalist_logs_in()
+        self._journalist_clicks_source_unread()
+        self._journalist_sees_missing_file_error_message()
+        self._is_on_journalist_homepage()
+
+    def test_select_source_and_download_all(self, missing_msg_file):
+        """Test behavior when the journalist selects the source then clicks the "Download" button
+        from the journalist home page."""
+        self._journalist_logs_in()
+        self._journalist_selects_first_source_then_download_all()
+        self._journalist_sees_missing_file_error_message()
+        self._is_on_journalist_homepage()
+
+    def test_select_source_and_download_unread(self, missing_msg_file):
+        """Test behavior when the journalist selects the source then clicks the "Download Unread"
+        button from the journalist home page."""
+        self._journalist_logs_in()
+        self._journalist_selects_first_source_then_download_unread()
+        self._journalist_sees_missing_file_error_message()
+        self._is_on_journalist_homepage()
+
+    def test_download_message(self, missing_msg_file):
+        """Test behavior when the journalist clicks on the individual message from the source page.
+        """
+        self._journalist_logs_in()
+        self._journalist_checks_messages()
+        self._journalist_downloads_message_missing_file()
+        self._journalist_sees_missing_file_error_message()
+        self._journalist_is_on_collection_page()
+
+    def test_select_message_and_download_selected(self, missing_msg_file):
+        """Test behavior when the journalist selects the individual message from the source page
+        then clicks "Download Selected"."""
+        self._journalist_logs_in()
+        self._journalist_selects_the_first_source()
+        self._journalist_selects_message_then_download_selected()
+        self._journalist_sees_missing_file_error_message()
+        self._journalist_is_on_collection_page()

securedrop/tests/test_journalist.py

@@ -2,7 +2,9 @@
 import base64
 import binascii
 import io
+from mock import call
 import os
+from pathlib import Path
 import pytest
 import random
 import zipfile
@@ -2286,6 +2288,97 @@ def test_download_selected_submissions_previously_downloaded(
             )
 
 
+@pytest.fixture(scope="function")
+def selected_missing_files(journalist_app, test_source):
+    """Fixture for the download tests with missing files in storage."""
+    source = Source.query.get(test_source["id"])
+    submissions = utils.db_helper.submit(source, 2)
+    selected = sorted([s.filename for s in submissions])
+
+    storage_path = Path(journalist_app.storage.storage_path)
+    msg_files = sorted([p for p in storage_path.rglob("*") if p.is_file()])
+    assert len(msg_files) == 2
+    for file in msg_files:
+        file.unlink()
+
+    yield selected
+
+
+def test_download_selected_submissions_missing_files(
+    journalist_app, test_journo, test_source, mocker, selected_missing_files
+):
+    """Tests download of selected submissions with missing files in storage."""
+    mocked_error_logger = mocker.patch('journalist.app.logger.error')
+    journo = Journalist.query.get(test_journo["id"])
+
+    with journalist_app.test_client() as app:
+        _login_user(
+            app,
+            journo.username,
+            test_journo["password"],
+            test_journo["otp_secret"]
+        )
+        resp = app.post(
+            url_for("main.bulk"),
+            data=dict(
+                action="download",
+                filesystem_id=test_source["filesystem_id"],
+                doc_names_selected=selected_missing_files,
+            )
+        )
+
+    assert resp.status_code == 302
+
+    expected_calls = []
+    for file in selected_missing_files:
+        missing_file = (
+            Path(journalist_app.storage.storage_path)
+            .joinpath(test_source["filesystem_id"])
+            .joinpath(file)
+            .as_posix()
+        )
+        expected_calls.append(call("File {} not found".format(missing_file)))
+
+    mocked_error_logger.assert_has_calls(expected_calls)
+
+
+def test_download_single_submission_missing_file(
+    journalist_app, test_journo, test_source, mocker, selected_missing_files
+):
+    """Tests download of single submissions with missing files in storage."""
+    mocked_error_logger = mocker.patch('journalist.app.logger.error')
+    journo = Journalist.query.get(test_journo["id"])
+    missing_file = selected_missing_files[0]
+
+    with journalist_app.test_client() as app:
+        _login_user(
+            app,
+            journo.username,
+            test_journo["password"],
+            test_journo["otp_secret"]
+        )
+        resp = app.get(
+            url_for(
+                "col.download_single_file",
+                filesystem_id=test_source["filesystem_id"],
+                fn=missing_file,
+            )
+        )
+
+    assert resp.status_code == 302
+
+    missing_file = (
+        Path(journalist_app.storage.storage_path)
+        .joinpath(test_source["filesystem_id"])
+        .joinpath(missing_file)
+        .as_posix()
+    )
+
+    mocked_error_logger.assert_called_once_with(
+        "File {} not found".format(missing_file)
+    )
+
+
 def test_download_unread_all_sources(journalist_app, test_journo):
     """
     Test that downloading all unread creates a zip that contains all unread submissions from the