Uploaded image for project: 'Qt'
  1. Qt
  2. QTBUG-56595

QXcbConnection::getTimestamp() returns old timestamp

    XMLWordPrintable

    Details

    • Commits:
      02248eea5562c1df39ee23f195011afacc6759b0 (qt/qtbase/dev) 73fc1f93e8bea1c493ed16655ad6fd68ae270e38 (qt/qtbase/5.12) bc60541d9f9fb477172ab08b41f45b7f95033c48 (qt/qtbase/6.1) 865a713d6bded5d19a64077a17b9295bbeb3b699 (qt/qtbase/6.2)

      Description

      QXcbConnection::getTimestamp() returns a timestamp from an earlier PropertyNotify event which was already in the event queue. I found this issue when I was trying to figure out why gvim (with GTK+) exits with a BadWindow error when selecting or copying a large text to the clipboard in a KDE environment. It turns out that GTK+ uses the INCR protocol to send the data and QT uses getTimestamp (in QXcbClipboard::clipboardReadProperty) to set the start time of the transfer. Since that start time is incorrect QT expects data which hasn't been sent yet and closes the window. GTK+ still tries to add the data to the window which causes a BadWindow error.

      Steps to reproduce:

      1. Create or use a large text file (e.g. cat /dev/urandom|base64 -w 200|head -n 5000>large_text_file).
      2. Open the text file in gvim (or another GTK+ based editor, as long as it uses the same clipboard mechanism).
      3. Start a Qt based text editor.
      4. In gvim, select and copy all text.
      5. Paste the text in the Qt based text editor.

      Note that when a clipboard manager like klipper is used, which automatically copies text to the clipboard, the problem occurs immediately after selecting the text.

        Attachments

          Issue Links

          No reviews matched the request. Check your Options in the drop-down menu of this sections header.

            Activity

              People

              Assignee:
              liaqi Liang Qi
              Reporter:
              ps0 Patrick Smits
              Votes:
              12 Vote for this issue
              Watchers:
              18 Start watching this issue

                Dates

                Created:
                Updated:
                Resolved:

                  Gerrit Reviews