From 828fe353817c78cec2ceb7c42ff0644069f46ba7 Mon Sep 17 00:00:00 2001
From: Nikita Popov <nikic@php.net>
Date: Fri, 5 Sep 2014 12:44:51 +0200
Subject: [PATCH] Fix string increment

---
 Zend/zend_operators.c                         |  5 +-
 tests/lang/operators/preinc_variationStr.phpt | 61 ++++++++++++-------
 2 files changed, 42 insertions(+), 24 deletions(-)

diff --git a/Zend/zend_operators.c b/Zend/zend_operators.c
index e4fdaa6f9e..2e48c154e9 100644
--- a/Zend/zend_operators.c
+++ b/Zend/zend_operators.c
@@ -2023,7 +2023,7 @@ static void increment_string(zval *str) /* {{{ */
 	}
 	s = Z_STRVAL_P(str);
 
-	while (pos >= 0) {
+	do {
 		ch = s[pos];
 		if (ch >= 'a' && ch <= 'z') {
 			if (ch == 'z') {
@@ -2059,8 +2059,7 @@ static void increment_string(zval *str) /* {{{ */
 		if (carry == 0) {
 			break;
 		}
-		pos--;
-	}
+	} while (pos-- > 0);
 
 	if (carry) {
 		t = zend_string_alloc(Z_STRLEN_P(str)+1, 0);
diff --git a/tests/lang/operators/preinc_variationStr.phpt b/tests/lang/operators/preinc_variationStr.phpt
index 010a237034..4e607057f7 100644
--- a/tests/lang/operators/preinc_variationStr.phpt
+++ b/tests/lang/operators/preinc_variationStr.phpt
@@ -1,22 +1,23 @@
---TEST--
-Test ++N operator : various numbers as strings
---FILE--
-<?php
-
-$strVals = array(
-   "0","65","-44", "1.2", "-7.7", "abc", "123abc", "123e5", "123e5xyz", " 123abc", "123 abc", "123abc ", "3.4a",
-   "a5.9"
-);
-
-
-foreach ($strVals as $strVal) {
-   echo "--- testing: '$strVal' ---\n";
-   var_dump(++$strVal);
-}
-   
-?>
-===DONE===
---EXPECT--
+--TEST--
+Test ++N operator : various numbers as strings
+--FILE--
+<?php
+
+$strVals = array(
+    "0","65","-44", "1.2", "-7.7",
+    "abc", "123abc", "123e5", "123e5xyz", " 123abc", "123 abc", "123abc ", "3.4a", "a5.9",
+    "z", "az", "zz", "Z", "AZ", "ZZ", "9z", "19z", "99z",
+);
+
+
+foreach ($strVals as $strVal) {
+    echo "--- testing: '$strVal' ---\n";
+    var_dump(++$strVal);
+}
+
+?>
+===DONE===
+--EXPECT--
 --- testing: '0' ---
 int(1)
 --- testing: '65' ---
@@ -44,5 +45,23 @@ string(7) "123abc "
 --- testing: '3.4a' ---
 string(4) "3.4b"
 --- testing: 'a5.9' ---
-string(4) "a5.0"
-===DONE===
+string(4) "a5.0"
+--- testing: 'z' ---
+string(2) "aa"
+--- testing: 'az' ---
+string(2) "ba"
+--- testing: 'zz' ---
+string(3) "aaa"
+--- testing: 'Z' ---
+string(2) "AA"
+--- testing: 'AZ' ---
+string(2) "BA"
+--- testing: 'ZZ' ---
+string(3) "AAA"
+--- testing: '9z' ---
+string(3) "10a"
+--- testing: '19z' ---
+string(3) "20a"
+--- testing: '99z' ---
+string(4) "100a"
+===DONE===
-- 
2.50.1