From 0729b111f20699a63f68ca3974fd05608943df8f Mon Sep 17 00:00:00 2001
From: Bas Leijdekkers <basleijdekkers@gmail.com>
Date: Fri, 19 Aug 2011 20:49:53 +0200
Subject: [PATCH] fix natural compare for string with big numbers

---
 .../openapi/util/text/StringUtil.java         | 37 +++++++++++++------
 .../intellij/util/text/StringUtilTest.java    |  2 +-
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/platform/util/src/com/intellij/openapi/util/text/StringUtil.java b/platform/util/src/com/intellij/openapi/util/text/StringUtil.java
index 776f513229a6..924f215f57b9 100644
--- a/platform/util/src/com/intellij/openapi/util/text/StringUtil.java
+++ b/platform/util/src/com/intellij/openapi/util/text/StringUtil.java
@@ -1971,19 +1971,34 @@ public class StringUtil {
     final int string1Length = string1.length();
     final int string2Length = string2.length();
     for(int i = 0, j = 0; i < string1Length && j < string2Length; i++, j++) {
-      final char ch1 = string1.charAt(i);
-      final char ch2 = string2.charAt(j);
-      if (isDigit(ch1) && isDigit(ch2)) {
+      char ch1 = string1.charAt(i);
+      char ch2 = string2.charAt(j);
+      if ((isDigit(ch1) || ch1 == ' ') && (isDigit(ch2) || ch2 == ' ')) {
         int startNum1 = i;
+        while (ch1 == ' ' || ch1 == '0') { // skip leading spaces and zeros
+          startNum1++;
+          if (startNum1 >= string1Length) break;
+          ch1 = string1.charAt(startNum1);
+        }
         int startNum2 = j;
-        i++;
-        j++;
+        while (ch2 == ' ' || ch2 == '0') {
+          startNum2++;
+          if (startNum2 >= string2Length) break;
+          ch2 = string2.charAt(startNum2);
+        }
+        i = startNum1;
+        j = startNum2;
         while (i < string1Length && isDigit(string1.charAt(i))) i++;
         while (j < string2Length && isDigit(string2.charAt(j))) j++;
-        final int difference = Integer.parseInt(string1.substring(startNum1, i)) -
-                               Integer.parseInt(string2.substring(startNum2, j));
-        if (difference != 0) {
-          return difference;
+        final int lengthDiff = (i - startNum1) - (j - startNum2);
+        if (lengthDiff != 0) {
+          return lengthDiff;
+        }
+        for (; startNum1 < i; startNum1++, startNum2++) {
+          final int diff = string1.charAt(startNum1) - string2.charAt(startNum2);
+          if (diff != 0) {
+            return diff;
+          }
         }
       } else {
         if (caseSensitive) {
@@ -2007,8 +2022,8 @@ public class StringUtil {
     return string1Length - string2Length;
   }
 
-  public static boolean isDigit(char c) {
-    return c >= '0' && c <= '9';
+  private static boolean isDigit(char c) {
+    return (c >= '0' && c <= '9');
   }
 
   public static int compare(@Nullable String s1, @Nullable String s2, boolean ignoreCase) {
diff --git a/platform/util/testSrc/com/intellij/util/text/StringUtilTest.java b/platform/util/testSrc/com/intellij/util/text/StringUtilTest.java
index 721b81254c63..92dd9046dfb6 100644
--- a/platform/util/testSrc/com/intellij/util/text/StringUtilTest.java
+++ b/platform/util/testSrc/com/intellij/util/text/StringUtilTest.java
@@ -81,7 +81,7 @@ public class StringUtilTest extends TestCase {
       }
     };
     Collections.sort(strings, c);
-    assertEquals(Arrays.asList("1.2.9.1", "1.2.10.5", "tes0", "test", "test 3", "test0", "test1", "test2", "test10", "test10a",
+    assertEquals(Arrays.asList("1.2.9.1", "1.2.10.5", "tes0", "test", "test0", "test1", "test2", "test 3", "test10", "test10a",
                                "test011", "Test99", "test99", "testing"), strings);
     final List<String> strings2 = new ArrayList(Arrays.asList("t1", "t001", "T2", "T002", "T1", "t2"));
     Collections.sort(strings2, c);