[claudiodekker]

When array_map() is compiled into a loop, the class name of a static first-class callable is compiled as an expression. That gives the name as written, without resolving it against the current namespace or use imports, so the call fails with "Class not found" at runtime:

<?php
namespace Foo {
    class Bar {
        public static function double(int $x): int { return $x * 2; }
    }
}

namespace {
    use Foo\Bar;

    var_dump(array_map(Bar::double(...), [1]));
    // PHP 8.5: array(1) { [0]=> int(2) }
    // PHP 8.6.0RC3: Uncaught Error: Class "Bar" not found
}

Only fully qualified names work. Inside a namespace the bug shows only with \array_map(), because an unqualified array_map() there isn't optimized. self, parent and static are not affected.

This was introduced in 40a8468 (GH-23254), which started evaluating the class name once before the loop. Bisected between RC3 and the point where PHP-8.6 branched from PHP-8.5.

The fix resolves a literal class name with zend_resolve_class_name_ast() before the loop body is compiled, the same way zend_compile_class_ref() does for a regular static call. self, parent, static and dynamic class expressions still take the existing path.

The new test covers imported, aliased, namespace\-relative and fully qualified names in the global namespace, a namespace-relative name under \array_map(), and self, parent and static inside a class.

Tested with make test TESTS="Zend/tests ext/opcache/tests ext/standard/tests/array" on --enable-debug and --enable-debug --enable-zts builds, with opcache off and on. The new test fails without the fix and passes with it.

[arnaud-lb]

Thank you!