Room: make downloaded file name building more robust

Specifically, handle colons and long file names gracefully. Closes #366.

1 files changed, 24 insertions, 16 deletions

diff --git a/lib/room.cpp b/lib/room.cpp
index 0a192203..b6925be5 100644
--- a/lib/room.cpp
+++ b/lib/room.cpp
@@ -1005,6 +1005,11 @@ QList<User*> Room::directChatUsers() const
     return connection()->directChatUsers(this);
 }
 
+QString safeFileName(QString rawName)
+{
+    return rawName.replace(QRegularExpression("[/\\<>|\"*?:]"), "_");
+}
+
 const RoomMessageEvent*
 Room::Private::getEventWithFile(const QString& eventId) const
 {
@@ -1020,20 +1025,20 @@ Room::Private::getEventWithFile(const QString& eventId) const
 
 QString Room::Private::fileNameToDownload(const RoomMessageEvent* event) const
 {
-    Q_ASSERT(event->hasFileContent());
+    Q_ASSERT(event && event->hasFileContent());
     const auto* fileInfo = event->content()->fileInfo();
     QString fileName;
     if (!fileInfo->originalName.isEmpty())
-        fileName = QFileInfo(fileInfo->originalName).fileName();
-    else if (!event->plainBody().isEmpty()) {
-        // Having no better options, assume that the body has
-        // the original file URL or at least the file name.
-        if (QUrl u { event->plainBody() }; u.isValid())
-            fileName = QFileInfo(u.path()).fileName();
+        fileName = QFileInfo(safeFileName(fileInfo->originalName)).fileName();
+    else if (QUrl u { event->plainBody() }; u.isValid()) {
+        qDebug(MAIN) << event->id()
+                     << "has no file name supplied but the event body "
+                        "looks like a URL - using the file name from it";
+        fileName = u.fileName();
     }
-    // Check the file name for sanity
-    if (fileName.isEmpty() || !QTemporaryFile(fileName).open())
-        return "file." % fileInfo->mimeType.preferredSuffix();
+    if (fileName.isEmpty())
+        return safeFileName(fileInfo->mediaId()).replace('.', '-') % '.'
+               % fileInfo->mimeType.preferredSuffix();
 
     if (QSysInfo::productType() == "windows") {
         if (const auto& suffixes = fileInfo->mimeType.suffixes();
@@ -1888,12 +1893,15 @@ void Room::downloadFile(const QString& eventId, const QUrl& localFilename)
     }
     const auto fileUrl = fileInfo->url;
     auto filePath = localFilename.toLocalFile();
-    if (filePath.isEmpty()) {
-        // Build our own file path, starting with temp directory and eventId.
-        filePath = eventId;
-        filePath = QDir::tempPath() % '/'
-                   % filePath.replace(QRegularExpression("[/\\<>|\"*?:]"), "_")
-                   % '#' % d->fileNameToDownload(event);
+    if (filePath.isEmpty()) { // Setup default file path
+        filePath =
+            fileInfo->url.path().mid(1) % '_' % d->fileNameToDownload(event);
+
+        if (filePath.size() > 200) // If too long, elide in the middle
+            filePath.replace(128, filePath.size() - 192, "---");
+
+        filePath = QDir::tempPath() % '/' % filePath;
+        qDebug(MAIN) << "File path:" << filePath;
     }
     auto job = connection()->downloadFile(fileUrl, filePath);
     if (isJobRunning(job)) {