ext/dom: Return numeric results from XPath callbacks as numbers

UPGRADING

@@ -28,6 +28,10 @@ PHP 8.6 UPGRADE NOTES
     from global scope" instead of the prior readonly modification error.
     ReflectionProperty::isWritable() also reports these properties
     accurately.
+  . Custom XPath functions registered via DOMXPath::registerPhpFunctionNS
+    or Dom\XPath::registerPhpFunctionNS returning 'int' or 'float' numbers
+    now provide XPath 'number' scalars. Very large integers >= 2^53 are
+    still returned as XPath strings to not lose precision.
 
 - GD:
   . imagesetstyle(), imagefilter() and imagecrop() filter their

ext/dom/tests/modern/xml/return_numeric_strings_from_xpath.phpt

@@ -0,0 +1,61 @@
+--TEST--
+Returning numeric string values from Dom\XPath callback functions for large integers
+--EXTENSIONS--
+dom
+--SKIPIF--
+<?php if (PHP_INT_SIZE !== 8) die("skip 64-bit only"); ?>
+--FILE--
+<?php
+define('MAX_SAFE_INTEGER', 2**53-1);
+
+$document = Dom\XMLDocument::createFromString('<root/>');
+$xpath = new Dom\XPath($document);
+$xpath->registerPhpFunctionNs('urn:x', 'get-int',                   fn(int $i): int => $i);
+$xpath->registerPhpFunctionNs('urn:x', 'get-float',                 fn(float $f): float => $f);
+$xpath->registerPhpFunctionNs('urn:x', 'get-max-safe-int',          fn() =>  MAX_SAFE_INTEGER);
+$xpath->registerPhpFunctionNs('urn:x', 'get-negative-max-safe-int', fn() => -MAX_SAFE_INTEGER);
+$xpath->registerPhpFunctionNs('urn:x', 'get-large-int',             fn() =>  MAX_SAFE_INTEGER+2);
+$xpath->registerPhpFunctionNs('urn:x', 'get-negative-large-int',    fn() => -MAX_SAFE_INTEGER-2);
+$xpath->registerNamespace('x', 'urn:x');
+
+var_dump($xpath->evaluate('x:get-float('.PHP_INT_MAX.')'));
+var_dump($xpath->evaluate('x:get-float('.PHP_INT_MIN.')'));
+var_dump($xpath->evaluate('x:get-float('.PHP_FLOAT_MAX.')'));
+var_dump($xpath->evaluate('x:get-float('.PHP_FLOAT_MIN.')'));
+var_dump($xpath->evaluate('x:get-float('.PHP_FLOAT_EPSILON.')'));
+
+var_dump(MAX_SAFE_INTEGER);
+var_dump(floatval(MAX_SAFE_INTEGER));
+var_dump($xpath->evaluate("x:get-int(".(MAX_SAFE_INTEGER).")"));
+var_dump($xpath->evaluate("x:get-int(".(-MAX_SAFE_INTEGER).")"));
+var_dump($xpath->evaluate("x:get-max-safe-int()"));
+var_dump($xpath->evaluate("x:get-negative-max-safe-int()"));
+
+var_dump(MAX_SAFE_INTEGER+2);
+// loses precision while type casting
+var_dump(floatval(MAX_SAFE_INTEGER+2));
+// loses precision while parameter passing int -> XPath number
+var_dump($xpath->evaluate("x:get-int(".(MAX_SAFE_INTEGER+2).")"));
+var_dump($xpath->evaluate("x:get-int(".(-MAX_SAFE_INTEGER-2).")"));
+// returns string values for integers larger than 2^53-1 to maintain precision
+var_dump($xpath->evaluate("x:get-large-int()"));
+var_dump($xpath->evaluate("x:get-negative-large-int()"));
+?>
+--EXPECT--
+float(9.223372036854778E+18)
+float(-9.223372036854778E+18)
+float(1.7976931348623E+308)
+float(2.2250738585072E-308)
+float(2.2204460492503003E-16)
+int(9007199254740991)
+float(9007199254740991)
+float(9007199254740991)
+float(-9007199254740991)
+float(9007199254740991)
+float(-9007199254740991)
+int(9007199254740993)
+float(9007199254740992)
+string(16) "9007199254740992"
+string(17) "-9007199254740992"
+string(16) "9007199254740993"
+string(17) "-9007199254740993"

ext/dom/tests/modern/xml/return_scalars_from_xpath.phpt

@@ -0,0 +1,49 @@
+--TEST--
+Returning scalar values from Dom\XPath callback functions
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+$document = Dom\XMLDocument::createFromString('<root/>');
+$xpath = new Dom\XPath($document);
+$xpath->registerPhpFunctionNs('urn:x', 'get-int',    fn(int $i): int => $i);
+$xpath->registerPhpFunctionNs('urn:x', 'get-float',  fn(float $f): float => $f);
+$xpath->registerPhpFunctionNs('urn:x', 'get-string', fn(string $s): string => $s);
+$xpath->registerPhpFunctionNs('urn:x', 'get-bool',   fn(bool $b): bool => $b);
+$xpath->registerNamespace('x', 'urn:x');
+
+var_dump($xpath->evaluate('x:get-string("test")'));
+var_dump($xpath->evaluate('x:get-bool(1)'));
+var_dump($xpath->evaluate('x:get-bool(0)'));
+
+var_dump($xpath->evaluate('x:get-int(41)'));
+var_dump($xpath->evaluate('x:get-int(41) + 1'));
+var_dump($xpath->evaluate('x:get-int(41)') + 1);
+var_dump($xpath->evaluate('x:get-float(4.2)'));
+var_dump($xpath->evaluate('2 * x:get-float(4.2)'));
+var_dump(2 * $xpath->evaluate('x:get-float(4.2)'));
+
+var_dump($xpath->evaluate('x:get-int(0)'));
+var_dump($xpath->evaluate('x:get-int(-0)'));
+var_dump($xpath->evaluate('x:get-float(0)'));
+var_dump($xpath->evaluate('x:get-float(-0)'));
+
+var_dump($xpath->evaluate('x:get-float(number("invalid"))'));
+var_dump($xpath->evaluate('x:get-float(1 div 0)'));
+?>
+--EXPECT--
+string(4) "test"
+bool(true)
+bool(false)
+float(41)
+float(42)
+float(42)
+float(4.2)
+float(8.4)
+float(8.4)
+float(0)
+float(0)
+float(0)
+float(-0)
+float(NAN)
+float(INF)

ext/dom/xpath_callbacks.c

@@ -25,6 +25,11 @@
 #include "internal_helpers.h"
 #include <libxml/parserInternals.h>
 
+#ifndef DBL_MANT_DIG
+# define DBL_MANT_DIG 53
+#endif
+#define MAX_SAFE_INTEGER ((1LL << DBL_MANT_DIG) - 1)
+
 static void xpath_callbacks_entry_dtor(zval *zv)
 {
 	zend_fcall_info_cache *fcc = Z_PTR_P(zv);
@@ -438,6 +443,11 @@ static zend_result php_dom_xpath_callback_dispatch(php_dom_xpath_callbacks *xpat
 			valuePush(ctxt, xmlXPathNewNodeSet(nodep));
 		} else if (Z_TYPE(callback_retval) == IS_FALSE || Z_TYPE(callback_retval) == IS_TRUE) {
 			valuePush(ctxt, xmlXPathNewBoolean(Z_TYPE(callback_retval) == IS_TRUE));
+		} else if (Z_TYPE(callback_retval) == IS_LONG &&
+			 Z_LVAL(callback_retval) >= -MAX_SAFE_INTEGER && Z_LVAL(callback_retval) <= MAX_SAFE_INTEGER) {
+			valuePush(ctxt, xmlXPathNewFloat(Z_LVAL(callback_retval)));
+		} else if (Z_TYPE(callback_retval) == IS_DOUBLE) {
+			valuePush(ctxt, xmlXPathNewFloat(Z_DVAL(callback_retval)));
 		} else if (Z_TYPE(callback_retval) == IS_OBJECT) {
 			zend_type_error("Only objects that are instances of DOM nodes can be converted to an XPath expression");
 			zval_ptr_dtor(&callback_retval);

ext/xsl/tests/xsltprocessor_registerPHPFunctionNS-numeric-results.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Returning numeric values from XSLTProcessor callbacks
+--EXTENSIONS--
+xsl
+--FILE--
+<?php
+$document = Dom\XMLDocument::createFromString('<root><a/><b/><c/><d/></root>');
+$xslt =<<<END
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+                version="1.0" xmlns:my="urn:my.ns">
+<xsl:output method="text" omit-xml-declaration="yes"/>
+<xsl:template match="/root">count: <xsl:value-of select="my:count(*)"/></xsl:template>
+</xsl:stylesheet>
+END;
+$stylesheet = Dom\XMLDocument::createFromString($xslt);
+$xsltProcessor = new XSLTProcessor;
+$xsltProcessor->importStylesheet($stylesheet);
+$xsltProcessor->registerPHPFunctionNS('urn:my.ns', 'count', fn(array $arg1) => count($arg1));
+var_dump($xsltProcessor->transformToXML($document));
+?>
+--EXPECT--
+string(8) "count: 4"