From ed528c7b3a5b01a8da03609a6e72d9d5cd791aea Mon Sep 17 00:00:00 2001
From: Alan Liu <alansliu@gmail.com>
Date: Wed, 24 May 2000 18:25:27 +0000
Subject: [PATCH] ICU-352 disallow bad ranges

X-SVN-Rev: 1458
---
 icu4c/source/i18n/uniset.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/icu4c/source/i18n/uniset.cpp b/icu4c/source/i18n/uniset.cpp
index b55ca3028d..c57f85261d 100644
--- a/icu4c/source/i18n/uniset.cpp
+++ b/icu4c/source/i18n/uniset.cpp
@@ -703,6 +703,14 @@ UnicodeString& UnicodeSet::parse(UnicodeString& pairsBuf /*result*/,
         } else if (lastOp == 0 && !isLiteral && (c == HYPHEN || c == INTERSECTION)) {
             lastOp = c;
         } else if (lastOp == HYPHEN) {
+            if (lastChar >= c) {
+                // Don't allow redundant (a-a) or empty (b-a) ranges;
+                // these are most likely typos.
+                //throw new IllegalArgumentException("Invalid range " + lastChar +
+                //                                       '-' + c);
+                status = U_ILLEGAL_ARGUMENT_ERROR;
+                return pairsBuf;
+            }
             addPair(pairsBuf, (UChar)lastChar, c);
             lastOp = 0;
             lastChar = -1;