From b29610b3cfc461e3cd119c6892c31a0832d9daaf Mon Sep 17 00:00:00 2001
From: Anthony Green <green@redhat.com>
Date: Wed, 25 Feb 2004 19:52:58 +0000
Subject: de-pessimization

From-SVN: r78447
---
 libjava/java/lang/StringBuffer.java | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

(limited to 'libjava/java/lang/StringBuffer.java')

diff --git a/libjava/java/lang/StringBuffer.java b/libjava/java/lang/StringBuffer.java
index 92f9615..293b97d 100644
--- a/libjava/java/lang/StringBuffer.java
+++ b/libjava/java/lang/StringBuffer.java
@@ -1,5 +1,6 @@
 /* StringBuffer.java -- Growable strings
-   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004
+   Free Software Foundation, Inc.
 
 This file is part of GNU Classpath.
 
@@ -205,10 +206,26 @@ public final class StringBuffer implements Serializable, CharSequence
     if (newLength < 0)
       throw new StringIndexOutOfBoundsException(newLength);
 
+    int valueLength = value.length;
+
+    /* Always call ensureCapacity_unsynchronized in order to preserve
+       copy-on-write semantics.  */
     ensureCapacity_unsynchronized(newLength);
-    while (count < newLength)
-      value[count++] = '\0';
-    count = newLength;
+
+    if (newLength < valueLength)
+      {
+        /* If the StringBuffer's value just grew, then we know that
+           value is newly allocated and the region between count and
+           newLength is filled with '\0'.  */
+	count = newLength;
+      }
+    else
+      {
+	/* The StringBuffer's value doesn't need to grow.  However,
+	   we should clear out any cruft that may exist.  */
+	while (count < newLength)
+          value[count++] = '\0';
+      }
   }
 
   /**
-- 
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