ICU-22707 Fix an ancient bug in moveIndex32

unicode-org · Jul 18, 2024 · d149089 · d149089
1 parent b3ec8d1
commit d149089
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/icu4j/main/core/src/test/java/com/ibm/icu/dev/test/rbbi/RBBITestMonkey.java b/icu4j/main/core/src/test/java/com/ibm/icu/dev/test/rbbi/RBBITestMonkey.java
@@ -2093,8 +2093,8 @@ static int moveIndex32(StringBuffer s, int pos, int amt) {
                 }
                 pos--;
                 c = s.charAt(pos);
-                if (UTF16.isTrailSurrogate(c) && pos >= 0) {
-                    c = s.charAt(pos);
+                if (UTF16.isTrailSurrogate(c) && pos > 0) {
+                    c = s.charAt(pos - 1);
                     if (UTF16.isLeadSurrogate(c)) {
                         pos--;
                     }