Fix compiler crash when decorator fn argument contains invalid reference#10858
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…ference When an extern fn is called with an invalid reference as an argument, return errorType instead of the declared return type constraint. This prevents the decorator from being called with an incorrect type and avoids internal compiler crashes. Also skip assignability checks in checkFunctionCallArguments when the resolved argument is errorType to avoid spurious secondary diagnostics. Co-authored-by: markcowl <1054056+markcowl@users.noreply.github.com>
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[WIP] Fix compiler crash for decorator with invalid extern fn reference
Fix compiler crash when decorator fn argument contains invalid reference
Jun 2, 2026
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When an
extern fnused as a decorator argument receives an invalid reference (e.g., a typo), the compiler was passing the function's declared return type constraint to the decorator implementation instead of skipping the decorator call. This caused internal crashes in decorator implementations that access properties on the argument.Changes
checkFunctionCall: ReturnerrorTypewhen arguments are unsatisfied outside template declarations, instead of returning the constraint type which passes downstream assignability checkscheckFunctionCallArguments: Skip assignability check when resolved argument iserrorType, preventing spurious secondary diagnostics (only the primaryinvalid-referror is reported)errorTypeinstead of the constraint type when function calls fail due to argument errors