Fix #49723 (Skip seek when unnecessary)

ext/spl/spl_iterators.c

@@ -2080,7 +2080,7 @@ static inline void spl_limit_it_seek(spl_dual_it_object *intern, long pos TSRMLS
 		zend_throw_exception_ex(spl_ce_OutOfBoundsException, 0 TSRMLS_CC, "Cannot seek to %ld which is behind offset %ld plus count %ld", pos, intern->u.limit.offset, intern->u.limit.count);
 		return;
 	}
-	if (instanceof_function(intern->inner.ce, spl_ce_SeekableIterator TSRMLS_CC)) {
+	if (pos != intern->current.pos && instanceof_function(intern->inner.ce, spl_ce_SeekableIterator TSRMLS_CC)) {
 		MAKE_STD_ZVAL(zpos);
 		ZVAL_LONG(zpos, pos);
 		spl_dual_it_free(intern TSRMLS_CC);

ext/spl/tests/bug49723.phpt

@@ -0,0 +1,16 @@
+--TEST--
+LimitIterator: do not seek if not needed 
+--FILE--
+<?php
+
+$it = new ArrayIterator(array());
+
+$lit = new LimitIterator($it, 0, 5);
+
+foreach ($lit as $v) {
+    echo $v;
+}
+?>
+===DONE===
+--EXPECT--
+===DONE===