Disconnecting nested c-shaped blocks causes blocks to disappear

[FlorianTschimben]

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Description

I created this Structure and when i drag the 2nd loop (count with i...) out of the outer loop, everything in it disappears, but the output code stays the same.

Reproduction steps

Build from Inside out

1. Recreate a structure with multiple loops in it like in the first picture
2. drag the second loop out of the first loop
3. watch the blocks disappear

Stack trace

block_svg.ts:298  Uncaught DOMException: Failed to execute 'insertBefore' on 'Node': The node before which the new node is to be inserted is not a child of this node.
    at BlockSvg$$module$build$src$core$block_svg.setParent (file:///C:/PSBlockly/blockly/blockly_compressed.js:1225:28)
    at RenderedConnection$$module$build$src$core$rendered_connection.disconnectInternal (file:///C:/PSBlockly/blockly/blockly_compressed.js:960:417)
    at RenderedConnection$$module$build$src$core$rendered_connection.disconnectInternal (file:///C:/PSBlockly/blockly/blockly_compressed.js:1204:479)
    at RenderedConnection$$module$build$src$core$rendered_connection.disconnect (file:///C:/PSBlockly/blockly/blockly_compressed.js:959:323)
    at BlockSvg$$module$build$src$core$block_svg.unplugFromStack_ (file:///C:/PSBlockly/blockly/blockly_compressed.js:977:134)
    at BlockSvg$$module$build$src$core$block_svg.unplug (file:///C:/PSBlockly/blockly/blockly_compressed.js:975:342)
    at InsertionMarkerPreviewer$$module$build$src$core$insertion_marker_previewer.hideInsertionMarker (file:///C:/PSBlockly/blockly/blockly_compressed.js:1387:315)
    at InsertionMarkerPreviewer$$module$build$src$core$insertion_marker_previewer.hidePreview (file:///C:/PSBlockly/blockly/blockly_compressed.js:1386:486)
    at BlockDragStrategy$$module$build$src$core$dragging$block_drag_strategy.updateConnectionPreview (file:///C:/PSBlockly/blockly/blockly_compressed.js:1215:492)
    at BlockDragStrategy$$module$build$src$core$dragging$block_drag_strategy.drag (file:///C:/PSBlockly/blockly/blockly_compressed.js:1214:256)

Screenshots

No response

Browsers

No response

[AlanVescoli]

I have the same problem

[BeksOmega]

Hello! I wasn't able to reproduce this :/ Can you recreate it on the playground?

[FlorianTschimben]

Hi,
Yes I can recreate it on the playground. Maybe my reprodution steps weren't clear enough, so I will describe again:

1. Take a repeat 10 times block
   
2. Take a repeat while and place it under the repeat 10 times block
   
3. Take a while block and place it in the repeat 10 times block
   
4. Take a repeat 10 times block and place it in the outer while block
   
5. Take another while block and place it under the other while block
   
6. Take a count with i block and place it over the other blocks
   
7. Now take a foreach block and place it over the count with i block
   

Now when you grab the count with i block out of the foreach, everything in it disappears

[AlanVescoli]

If you build this from the inside out it also reproduces it. So start with the repeat then the count and then the for each

In my experience it happens when you add to a already existing block or mutiple blocks the outer two blocks(first count with, then for each) on outside

[BeksOmega]

Ok sweet, thank you for the repro steps! Building from the inside to the outside reproduces the problem. You can also do it with three nested "if" blocks, so I don't think this is specific to loops.

[BeksOmega]

I'm looking into this pre-triage b/c it's pretty bad.