From: Aaron Schulz <aschulz@wikimedia.org>
Date: Fri, 31 May 2013 23:12:18 +0000 (-0700)
Subject: Simplified IPv6 regex per comment
X-Git-Tag: 1.31.0-rc.0~18515
X-Git-Url: http://git.cyclocoop.org/%40spipnet%40?a=commitdiff_plain;h=2d56adb39328ac086bed031bc47b1c1448ee1db5;p=lhc%2Fweb%2Fwiklou.git

Simplified IPv6 regex per comment

* We already require PHP 5.3.2, which includes PCRE 7.2+.
  PHP 5.2.4 includes PCRE 7.2 per http://php.net/ChangeLog-5.php.

Change-Id: Ie9c1a0a93bef30a3a67e0140e621814351f8cea1
---

diff --git a/includes/IP.php b/includes/IP.php
index fc76310aa8..73834a5950 100644
--- a/includes/IP.php
+++ b/includes/IP.php
@@ -39,18 +39,11 @@ define( 'RE_IPV6_ADD',
 		':(?::|(?::' . RE_IPV6_WORD . '){1,7})' .
 	'|' . // ends with "::" (except "::")
 		RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){0,6}::' .
-	'|' . // contains one "::" in the middle, ending in "::WORD"
-		RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){0,5}' . '::' . RE_IPV6_WORD .
-	'|' . // contains one "::" in the middle, not ending in "::WORD" (regex for PCRE 4.0+)
-		RE_IPV6_WORD . '(?::(?P<abn>:(?P<iabn>))?' . RE_IPV6_WORD . '(?!:(?P=abn))){1,5}' .
-			':' . RE_IPV6_WORD . '(?P=iabn)' .
-		// NOTE: (?!(?P=abn)) fails iff "::" used twice; (?P=iabn) passes iff a "::" was found.
+	'|' . // contains one "::" in the middle (the ^ makes the test fail if none found)
+		RE_IPV6_WORD . '(?::((?(-1)|:))?' . RE_IPV6_WORD . '){1,6}(?(-2)|^)' .
 	'|' . // contains no "::"
 		RE_IPV6_WORD . '(?::' . RE_IPV6_WORD . '){7}' .
 	')'
-	// NOTE: With PCRE 7.2+, we can combine the two '"::" in the middle' cases into:
-	//		RE_IPV6_WORD . '(?::((?(-1)|:))?' . RE_IPV6_WORD . '){1,6}(?(-2)|^)'
-	// This also improves regex concatenation by using relative references.
 );
 // An IPv6 block is an IP address and a prefix (d1 to d128)
 define( 'RE_IPV6_BLOCK', RE_IPV6_ADD . '\/' . RE_IPV6_PREFIX );