ID 486216 - A crash occurs when viewing or rendering a Write with a Merge(Under) upstream with more than 1 input for A

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Problem summary
A crash occurs when viewing or rendering a Write with a Merge(Under) upstream with more than 1 input for A.

Customer reported version
nuke.12.2v2

Customer reported platform
windows10

Steps to reproduce
1) In Nuke, create two Constant nodes.
2) Create a Merge node and add both Constant nodes as the input A/B.
3) In the Merge Properties, set the operation to Under.
4) Add a Write node and set the file name.
5) Add another Constant node as an A2 input to the Merge node upstream.
6) Render the Write node.

Expected behavior
The application should continue rendering the files or displaying in the Viewer.

Actual behavior
The application crashes when rendering with the Write node, or after adding another A input while viewing the Write node.

Workaround
Using more than 1 Merge node for each A input prevents a crash.

Reproduced by support
Nuke 16.0v1 - Windows 11, Rocky 9
Nuke 15.0v1 - Windows 11
Nuke 14.0v1 - Windows 11 -- Regression

Unable to reproduce bug in:
Nuke 16.0v1 - macOS 14 Sonoma
Nuke 14.0v1 - CentOS 7,  macOS 14 Sonoma
Nuke 13.2v8 - Windows 11, macOS 14 Sonoma

Nuke 13.0v4 - Windows 10, macOS 10.14
Nuke 13.0v1 - Windows 10
Nuke 12.2v1 - Windows 10
Nuke 12.1v1 - Windows 10
Nuke 12.0v1 - Windows 10, macOS 10.14 -- Regression

Unable to reproduce bug in:
Nuke 11.3v6 - Windows 10, macOS 10.14

Earliest version tested
Nuke 11.3v6 - This issue doesn't appear in this version and has regressed

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