From 3f723a2a74fcd91c988f26e428106b3b4a08358e Mon Sep 17 00:00:00 2001
From: Timm Friebe <thekid@thekid.de>
Date: Mon, 16 Jan 2017 16:26:20 +0100
Subject: [PATCH] Add BC for PHP 7.2, see https://bugs.php.net/bug.php?id=73947

---
 ChangeLog.md                                           |  6 ++++++
 src/main/php/text/regex/MatchResult.class.php          | 10 +++++++++-
 src/test/php/text/regex/unittest/PatternTest.class.php |  8 ++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index c7fa78d..a42b916 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -3,6 +3,12 @@ Pattern matching changelog
 
 ## ?.?.? / ????-??-??
 
+## 7.1.1 / 2017-01-16
+
+* Added BC for PHP 7.2: Empty optional patterns should not be NULLed
+  See https://bugs.php.net/bug.php?id=73947
+  (@thekid) 
+
 ## 7.1.0 / 2016-08-29
 
 * Added version compatibility with XP 8 - @thekid
diff --git a/src/main/php/text/regex/MatchResult.class.php b/src/main/php/text/regex/MatchResult.class.php
index 82f85de..7ad6218 100755
--- a/src/main/php/text/regex/MatchResult.class.php
+++ b/src/main/php/text/regex/MatchResult.class.php
@@ -25,7 +25,15 @@ static function __static() {
    */
   public function __construct($length, $matches) {
     $this->length= $length;
-    $this->matches= $matches;
+
+    // Ensure empty patterns are not NULLed to ensure BC.
+    // See https://bugs.php.net/bug.php?id=73947
+    foreach ($matches as $group => $match) {
+      $this->matches[$group]= [];
+      foreach ($match as $i => $segment) {
+        $this->matches[$group][$i]= (string)$segment;
+      }
+    }
   }
   
   /**
diff --git a/src/test/php/text/regex/unittest/PatternTest.class.php b/src/test/php/text/regex/unittest/PatternTest.class.php
index 876a41b..0adde5c 100644
--- a/src/test/php/text/regex/unittest/PatternTest.class.php
+++ b/src/test/php/text/regex/unittest/PatternTest.class.php
@@ -202,4 +202,12 @@ public function stringCastWithFlag() {
   public function stringCastWithFlags() {
     $this->assertEquals('/end$/iU', (string)new Pattern('end$', Pattern::CASE_INSENSITIVE | Pattern::UNGREEDY));
   }
+
+  #[@test]
+  public function php_bug_73947() {
+    $this->assertEquals(
+      ['http://domain', 'http', '', 'domain'],
+      Pattern::compile('([a-z]+)://([^@]+@)?([a-z]+)')->match('http://domain')->group(0)
+    );
+  }
 }