From 09dce103f2bd6e621a153da3f399d2c52a9f668e Mon Sep 17 00:00:00 2001
From: Frank Tang <ftang@chromium.org>
Date: Tue, 11 Jun 2024 14:33:25 -0700
Subject: [PATCH] ICU-22797 Move the loop limit before ignore continue

Fix an infinity loop issue inside collation builder
---
 icu4c/source/i18n/collationbuilder.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/icu4c/source/i18n/collationbuilder.cpp b/icu4c/source/i18n/collationbuilder.cpp
index b243992cc58b..af631e6a52ef 100644
--- a/icu4c/source/i18n/collationbuilder.cpp
+++ b/icu4c/source/i18n/collationbuilder.cpp
@@ -1138,12 +1138,12 @@ CollationBuilder::addOnlyClosure(const UnicodeString &nfdPrefix, const UnicodeSt
         for(;;) {
             UnicodeString str = stringIter.next();
             if(str.isBogus()) { break; }
-            if(ignoreString(str, errorCode) || str == nfdString) { continue; }
             if (loop++ > kClosureLoopLimit) {
                 // To avoid hang as in ICU-22517, return with error.
                 errorCode = U_INPUT_TOO_LONG_ERROR;
                 return ce32;
             }
+            if(ignoreString(str, errorCode) || str == nfdString) { continue; }
             ce32 = addIfDifferent(prefix, str, newCEs, newCEsLength, ce32, errorCode);
             if(U_FAILURE(errorCode)) { return ce32; }
         }
@@ -1159,12 +1159,12 @@ CollationBuilder::addOnlyClosure(const UnicodeString &nfdPrefix, const UnicodeSt
             for(;;) {
                 UnicodeString str = stringIter.next();
                 if(str.isBogus()) { break; }
-                if(ignoreString(str, errorCode) || (samePrefix && str == nfdString)) { continue; }
                 if (loop++ > kClosureLoopLimit) {
                     // To avoid hang as in ICU-22517, return with error.
                     errorCode = U_INPUT_TOO_LONG_ERROR;
                     return ce32;
                 }
+                if(ignoreString(str, errorCode) || (samePrefix && str == nfdString)) { continue; }
                 ce32 = addIfDifferent(prefix, str, newCEs, newCEsLength, ce32, errorCode);
                 if(U_FAILURE(errorCode)) { return ce32; }
             }