Null-safe operator loses type in loop

[leongersen]

Bug report

These expressions should be equivalent (when the result of mergeWith cannot be null):

$mergedExample = $mergedExample !== null ? $mergedExample->mergeWith() : $example;

$mergedExample = $mergedExample?->mergeWith() ?? $example;

The expression with the null safe operator results in mixed for $mergedExample, the ternary expression is analysed correctly.

Code snippet that reproduces the problem

https://phpstan.org/r/a88e69f2-8ca7-471b-beb4-fd427772df0a

Expected output

The dumped type for $mergedExample should be Example.

Did PHPStan help you today? Did it make you happy in any way?

No response

[phpstan-bot]

@leongersen After the latest push in 1.11.x, PHPStan now reports different result with your code snippet:

@@ @@
 17: Dumped type: Example
-21: Dumped type: mixed
+21: Dumped type: Example

Full report

Line	Error
17	Dumped type: Example
21	Dumped type: Example

[leongersen]

Thank you @ondrejmirtes 😄

[github-actions]

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