Video motion value for sprite is always zero until the sprite is interacted

[apple502j]

Expected Behavior

As long as the user accepts video, video motion value is set correctly.

Actual Behavior

Until the sprite is interacted, motion for the sprite is always 0 and direction is always -1. Values for stage are correct. There is no error on console.

"Interacting" includes:

• dragging, either on editor or on player (by set drag mode)
• clicking the sprite
• using say block, think block or ask block
• changing sprite selection from other sprite to the sprite
• using touching color/object block
• stamping

"Interacting" does not include:

• changing x/y
• changing direction
• changing draggability
• changing rotation style
• changing costume
• changing size
• changing graphic effect
• show/hide
• changing layer
• changing video transparency
• switching video on/off/flipped
• using pen extension (except stamp)

Steps to Reproduce

1. Make a project using "when video motion > 0" block
2. Save and reload
3. Allow video permission
4. Dance (script not executed)
5. Interact with the sprite (script get executed)

Operating System and Browser

Firefox 79 Windows 10

original repro by Blue_Science: My browser / operating system: Ubuntu Linux, Firefox 79.0, Flash 32.0 (release 0)

[ericrosenbaum]

e.g. my falling sprites project seems broken: https://scratch.mit.edu/projects/276660492/

[apple502j]

@ericrosenbaum @BryceLTaylor Can you bump this to priority 2? Search shows that 15 issues are marked with High Severity, Medium Impact and priority 2 while 9 issues are marked with priority 3 and this is not an environment-specific bug or anything that is hard to repro.