commit 1823fbc0d2e367487d6453caccdb651cf33d294a
author Peter Edberg <pedberg@unicode.org> Wed Sep 25 18:17:03 2019 -0700
committer pedberg-icu <42151464+pedberg-icu@users.noreply.github.com> Thu Sep 26 11:18:39 2019 -0700
tree e82df5a240027996719baa7afe40cad1e7720ca6
parent 4f72eea0261888239ce7822ba19af222eed22a48

ICU-20831 clone capitalizationBrkIter for actual use

icu4j/main/classes/core/src/com/ibm/icu/text/SimpleDateFormat.java

diff --git a/icu4j/main/classes/core/src/com/ibm/icu/text/SimpleDateFormat.java b/icu4j/main/classes/core/src/com/ibm/icu/text/SimpleDateFormat.java
index 7cf6a54..090e956 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/text/SimpleDateFormat.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/text/SimpleDateFormat.java
@@ -925,7 +925,7 @@
     private volatile TimeZoneFormat tzFormat;
 
     /**
-     * BreakIterator to use for capitalization
+     * BreakIterator to use for capitalization (will be cloned for actual use)
      */
     private transient BreakIterator capitalizationBrkIter = null;
 
@@ -2078,8 +2078,11 @@
                     // should only happen when deserializing, etc.
                     capitalizationBrkIter = BreakIterator.getSentenceInstance(locale);
                 }
+                // Note, the call to UCharacter.toTitleCase below is the only place that
+                // (the clone of) capitalizationBrkIter is actually used.
+                BreakIterator mutableCapitalizationBrkIter = (BreakIterator)capitalizationBrkIter.clone();
                 String firstField = buf.substring(bufstart); // bufstart or beginOffset, should be the same
-                String firstFieldTitleCase = UCharacter.toTitleCase(locale, firstField, capitalizationBrkIter,
+                String firstFieldTitleCase = UCharacter.toTitleCase(locale, firstField, mutableCapitalizationBrkIter,
                                                      UCharacter.TITLECASE_NO_LOWERCASE | UCharacter.TITLECASE_NO_BREAK_ADJUSTMENT);
                 buf.replace(bufstart, buf.length(), firstFieldTitleCase);
             }