Migrating issues to Github, please follow the new discussion here: https://github.com/Mudlet/Mudlet/issues/785
This issue needs to be closed and there is no appropriate status, so will set it to "Opinion" just for migration purposes. ** Bug watch added: github.com/Mudlet/Mudlet/issues #785 https://github.com/Mudlet/Mudlet/issues/785 ** Changed in: mudlet Status: New => Opinion -- You received this bug notification because you are a member of Mudlet Makers, which is subscribed to Mudlet. https://bugs.launchpad.net/bugs/1471508 Title: No Qt QDatastream version control handling Status in Mudlet: Opinion Bug description: In https://bugs.launchpad.net/mudlet/+bug/1471406 several issues were mentioned, this is one specific issue: The Qt documents note: " QDataStream's binary format has evolved since Qt 1.0, and is likely to continue evolving to reflect changes done in Qt. When inputting or outputting complex types, it's very important to make sure that the same version of the stream (version()) is used for reading and writing. If you need both forward and backward compatibility, you can hardcode the version number in the application: stream.setVersion(QDataStream::Qt_4_0); " We do not currently do this, so, theoretically if someone tries to load a map file format version 4 (the earliest that we still support) there is no guarantee that the current Qt libraries will parse the serialized bytes in the same manner as they did in the past - however by addressing that, this become an issue that we can solve for the future. I would suggest that for the moment we use Qt_4_6 WHEN WRITING as I think that will be compatible with what was used when the binaries for Mudlet 2.1 were created. I have checked the differences between Qt_4_8 (which is THE SAME as Qt_4_6, QDataStream enum value 12) and the current (Qt_5_4 enum value 16) and the differences are: QDateTime: Date (QDate) Time (QTime) 0 for Qt::LocalTime, 1 for Qt::UTC (quint8) *** ONLY IN Qt_5_4 *** 2 for Qt::OffsetFromUTC = An offset in seconds from Coordinated Universal Time. 3 for Qt::TimeZone = A named time zone using a specific set of Daylight Savings rules. ********************** *** Only in Qt_5_4 QMargins: left (int) top (int) right (int) bottom (int) QRegularExpression: The regular expression pattern (QString) The pattern options (quint32) *** In addition in: QMatrix4x4 QQuaternion QVector2D QVector3D QVector4D *** In Qt_5_4 *** All the above have several elements that are ALL floats NOT doubles *** The only ones that could be relevant to us here is QDateTime but we do not (currently) save such a value in any of the different files AFAICT and QVector3D (which is unused) in two places in TArea as span and pos, I'm not totally clear on the number of bytes used for a float and how that compares to a double (more for the latter) so that ought to mean we should be having problems but it is not clear that we are - I'll try to download a windows binary version of 2.1 and see what happens if I create a map with that and then load it into a current Mudlet version compiled with Qt5.4... UPDATE TO FOLLOW...(I need some sleep) To manage notifications about this bug go to: https://bugs.launchpad.net/mudlet/+bug/1471508/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~mudlet-makers Post to : [email protected] Unsubscribe : https://launchpad.net/~mudlet-makers More help : https://help.launchpad.net/ListHelp
