When `IMap::Load` fails, other components will continue to use the old map. However, if `IMap::Load` failed after the map was already successfully read with the datafile reader then other components kept their pointers to the old, invalid datafile reader items and data, causing random crashes in collision code. This is fixed by using a separate datafile reader to read the new map and only applying the datafile reader globally when loading was entirely successfully.
An error message is added for the case that a map has an unsupported version, which is currently the only case where a map can fail to load after the datafile was read successfully.
In particular, the block maps `blmapPepe`, `blmapV5` and `blmapDT-UPTU` did not have a version map item and were fixed separately.
Closes#7218. Regression from #5737.
Previously it reported the internal file data size (compressed). This
made the `map_resave` tool do the wrong job.
Co-authored-by: heinrich5991 <heinrich5991@gmail.com>
To reduce duplicate code and to add validation for tile skip everywhere.
Add separate `CMapItemLayerTilemap::TILE_SKIP_MIN_VERSION` constant and change `CMapItemVersion::CURRENT_VERSION` back to the previous version, as maps with tile skip can be loaded but skip is not used when saving.
SHA256 was chosen because it is reasonably standard, the file names
don't explode in length (this rules out SHA512) and it is supported by
basically all versions of OpenSSL (this rules out SHA512/256 and SHA3).
The protocol is changed in a backward compatible way: The supporting
server sends the SHA256 corresponding to the map in the `MAP_DETAILS`
message prior to sending the `MAP_CHANGE` message. The client saves the
SHA256 obtained from the `MAP_DETAILS` message until the next
`MAP_CHANGE` message.
For servers not supporting this protocol, the client falls back to
simply opening maps like in the previous scheme.
Remove the `map_version` tool, it is not being used and would have been
a little bit effort to update.
Use the OpenSSL implementation of SHA256 if it is supported, otherwise
fall back to a public domain one.
Fix#1127.