From 107443b311a7fef97ae0815203a956d4c35fdcfe Mon Sep 17 00:00:00 2001
From: Niels Dossche <7771979+nielsdos@users.noreply.github.com>
Date: Sat, 9 Sep 2023 21:17:02 +0200
Subject: [PATCH] Fix #52751: XPath processing-instruction() function is not
 supported.

Closes GH-12165.
---
 NEWS                              |  4 +++
 ext/simplexml/simplexml.c         |  2 +-
 ext/simplexml/tests/bug52751.phpt | 58 +++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 ext/simplexml/tests/bug52751.phpt

diff --git a/NEWS b/NEWS
index a68a41ad392..d8082b1eb7f 100644
--- a/NEWS
+++ b/NEWS
@@ -33,6 +33,10 @@ PHP                                                                        NEWS
   . Fixed persistent procedural ODBC connections not getting closed.
     (NattyNarwhal)
 
+- SimpleXML:
+  . Fixed bug #52751 (XPath processing-instruction() function is not
+    supported). (nielsdos)
+
 - SPL:
   . Fixed bug GH-11972 (RecursiveCallbackFilterIterator regression in 8.1.18).
     (nielsdos)
diff --git a/ext/simplexml/simplexml.c b/ext/simplexml/simplexml.c
index 8743a068cb6..57c0627d61a 100644
--- a/ext/simplexml/simplexml.c
+++ b/ext/simplexml/simplexml.c
@@ -1322,7 +1322,7 @@ PHP_METHOD(SimpleXMLElement, xpath)
 
 		for (i = 0; i < result->nodeNr; ++i) {
 			nodeptr = result->nodeTab[i];
-			if (nodeptr->type == XML_TEXT_NODE || nodeptr->type == XML_ELEMENT_NODE || nodeptr->type == XML_ATTRIBUTE_NODE) {
+			if (nodeptr->type == XML_TEXT_NODE || nodeptr->type == XML_ELEMENT_NODE || nodeptr->type == XML_ATTRIBUTE_NODE || nodeptr->type == XML_PI_NODE) {
 				/**
 				 * Detect the case where the last selector is text(), simplexml
 				 * always accesses the text() child by default, therefore we assign
diff --git a/ext/simplexml/tests/bug52751.phpt b/ext/simplexml/tests/bug52751.phpt
new file mode 100644
index 00000000000..de5d58e9e63
--- /dev/null
+++ b/ext/simplexml/tests/bug52751.phpt
@@ -0,0 +1,58 @@
+--TEST--
+Bug #52751 (XPath processing-instruction() function is not supported)
+--EXTENSIONS--
+simplexml
+--FILE--
+<?php
+
+$xml = <<<XML
+<?xml version="1.0" encoding="utf-8"?>
+<foo>
+  <bar>text node</bar>
+  <bar><?baz href="ftw" ?></bar>
+  <bar><?foo bar ?></bar>
+</foo>
+XML;
+
+$sxe = simplexml_load_string($xml);
+
+var_dump(
+    $sxe->xpath('//bar')
+);
+
+var_dump(
+    $sxe->xpath('//processing-instruction(\'baz\')')
+);
+
+foreach ($sxe->xpath('//processing-instruction()') as $pi) {
+    var_dump($pi->getName());
+}
+
+?>
+--EXPECT--
+array(3) {
+  [0]=>
+  object(SimpleXMLElement)#2 (1) {
+    [0]=>
+    string(9) "text node"
+  }
+  [1]=>
+  object(SimpleXMLElement)#3 (1) {
+    ["baz"]=>
+    object(SimpleXMLElement)#5 (0) {
+    }
+  }
+  [2]=>
+  object(SimpleXMLElement)#4 (1) {
+    ["foo"]=>
+    object(SimpleXMLElement)#5 (0) {
+    }
+  }
+}
+array(1) {
+  [0]=>
+  object(SimpleXMLElement)#4 (0) {
+  }
+}
+string(3) "baz"
+string(3) "foo"