This fixes future issues like bug #3614654:
"ALL: ScummVM 1.5.0 can't read newer saved games".
There are a few behavior changes introduced with this commit:
- checkThumbnailHeader will now also report the presence of
unsupported/broken (but skippable) headers.
- skipThumbnail will also try to skip the data for broken/unsupported
thumbnail data.
- loadThumbnail will skip over broken/unsupported thumbnail data but still
return 0 in this case.
This allows any 2Bpp/4Bpp Surfaces to be written via saveThumbnail
and loadThumbnail now. It furthermore will preserve the loaded Surface
in loadThumbnail.
MKID_BE relied on unspecified behavior of the C++ compiler,
and as such was always a bit unsafe. The new MKTAG macro
is slightly less elegant, but does no longer depend on the
behavior of the compiler.
Inspired by FFmpeg, which has an almost identical macro.
- Extended SCUMM engine to support savegames without thumbnail header. (Increased savegame version to prevent saves to be loaded from older ScummVM versions)
- Fixed KYRA to properly support savegames without thumbnail header.
svn-id: r34054
