Scratch-gui: Weird behavior when clicking a stacked translate blocks.

[cyx2015s]

Expected Behavior

It pops a text and stop.

Actual Behavior

Steps to Reproduce

Stack blocks like this

Operating System and Browser

Win 8, Google Chrome 68

[Kenny2github]

Can reproduce on develop with Chrome 68 Windows 10.
Note: Steps to reproduce in issue description did NOT work, only the configuration in the "Actual behavior" section showed this problem.

Actual Steps to Reproduce

1. Stack blocks like so:
   
2. Click on any block in the stack.

Important part is that there MUST be a reporter block in the input.

OS, Branch, and Browser

Windows 10, develop, Chrome 68
I noticed that the language is irrelevant to the issue, setting the language to Simplified Chinese or English made no difference.

[picklesrus]

This stack trace that seems to happen when clicking an individual translate block is perhaps related?
raven.js:429 Uncaught TypeError: Cannot set property 'null' of null
at e.exports (lib.min.js:114)
at e.value (lib.min.js:114)
at e.value (lib.min.js:114)
at A.value (lib.min.js:47)
at lib.min.js:47
at d (raven.js:425)
e.exports @ lib.min.js:114
value @ lib.min.js:114
value @ lib.min.js:114
value @ lib.min.js:47
(anonymous) @ lib.min.js:47
d @ raven.js:425

[picklesrus]

I think this actually happens every time you run a translate block with a new word/language pair. (The most recent word/language pair value is cached in the extension code itself).

There's a js error with this stack trace:
execute.js:457 Uncaught TypeError: Cannot set property 'null' of null
at execute (execute.js:457)
at Sequencer.stepThread (sequencer.js:207)
at Sequencer.stepThreads (sequencer.js:123)
at Runtime._step (runtime.js:1752)
at runtime.js:2261

That is coming from the following line where both the argValues and the inputValue are null.

https://github.com/LLK/scratch-vm/blob/develop/src/engine/execute.js#L457
The opCached object exists, but the _parentKey and parentValue properties on it are null. I'm not sure what they're supposed to be though.

[picklesrus]

Fixed by https://github.com/LLK/scratch-vm/pull/1853