SCUMM: MM (C64) - Graphical glitch with alien in telescope

[dp304]

Debian 10 x86_64
ScummVM 2.0.0
Maniac Mansion C64/English

The graphics are corrupted when the alien appears in the telescope, see screenshot.

To reproduce: load the attached save game, and use really powerful telescope.

This may be due to a corruption in the disk image, but apparently disk images from different download sources are identical in this regard: in MANIAC2.D64, at offset 0x29fff (i.e. within the pic map of Room 35), there is a 0x4B value, which should rather be 0x82.

(Btw. this would also cause a buffer overrun by 24 bytes in ScummVM, if it weren't for the extra space allocated for GdiV1::_V1.picMap. To make it safer, there should be x<size checks in GdiV1::decodeV1Gfx() before all three occurrences of writing to dst[x], which would log a warning about incorrect encoding and return from the function if x is too large.)

[AndywinXp]

Hmm... it seems to work properly nowadays. Closing