Use --with-libxml instead of --enable-libxml for PHP 7.4

Author: morozov

src/PhpBrew/VariantBuilder.php

@@ -727,13 +727,21 @@ public function __construct()
         $this->variants['xml'] = function (Build $build) {
             $options = array(
                 '--enable-dom',
-                '--enable-libxml',
+            );
+
+            if ($build->compareVersion('7.4') < 0) {
+                $options[] = '--enable-libxml';
+            } else {
+                $options[] = '--with-libxml';
+            }
+
+            $options = array_merge($options, array(
                 '--enable-simplexml',
                 '--enable-xml',
                 '--enable-xmlreader',
                 '--enable-xmlwriter',
                 '--with-xsl',
-            );
+            ));
 
             do {
                 if ($bin = Utils::findBin('brew')) {

tests/PhpBrew/VariantBuilderTest.php

@@ -164,4 +164,31 @@ public function testNeutralVirtualVariant()
         });
         $this->assertEquals(array(), $actual);
     }
+
+    /**
+     * @param string $version
+     * @param string $expected
+     *
+     * @dataProvider libXmlProvider
+     */
+    public function testLibXml($version, $expected)
+    {
+        $build = new Build($version);
+        $build->enableVariant('xml');
+
+        $builder = new VariantBuilder();
+        $options = $builder->build($build);
+
+        $this->assertContains($expected, $options);
+    }
+
+    public static function libXmlProvider()
+    {
+        return array(
+            array('7.3.0', '--enable-libxml'),
+
+            // see https://github.com/php/php-src/pull/4037
+            array('7.4.0-dev', '--with-libxml'),
+        );
+    }
 }