Fix crash when a partial skips a param with a constant default#184
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Fix crash when a partial skips a param with a constant default#184iliaal wants to merge 1 commit into
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When a partial leaves an optional parameter unbound (a positional gap from named arguments) and its default is a constant expression, the default AST was compiled into the forwarding call as an uncompilable ZEND_AST_CONSTANT node: an assertion in debug builds, undefined behavior otherwise. For a user function, skip the parameter and pass the following arguments by name so the target applies its own default at call time; this materializes no value and handles every default kind, including enum cases that cannot be a literal. Internal functions still pass an explicit default and error if it is not introspectable.
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A partial that leaves an optional parameter unbound via a named-argument gap, where that parameter's default is a constant expression, crashes the compiler.
f(a: 10, c: ?)forfunction f($a, $b = SOME_CONST, $c = 0)compiled the callee default into the generated forwarding call as aZEND_AST_CONSTANTnode, whichzend_compile_expr_innerhas no case for:ZEND_ASSERT(0)in debug,__builtin_unreachableUB in release. A plain literal default ($b = 5) is unaffected.For a user function, this skips the unbound parameter in the forwarding call and passes the following arguments by name, so the target applies its own default at call time. That matches a normal call exactly (verified for global constants,
self::class constants, and enum cases) and materializes no value, so it is safe under opcache for defaults that cannot be stored as a literal, such as enum cases. Internal functions are unchanged: they still pass an explicit default and error when it is not introspectable.