CODEC-232 URLCodec is neither immutable nor threadsafe

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@1789142 13f79535-47bb-0310-9956-ffa450edef68

Author: sebbASF

src/changes/changes.xml

@@ -45,6 +45,7 @@ The <action> type attribute can be add,update,fix,remove.
     <release version="1.11" date="2017-MM-DD" description="Feature and fix release.">
       <!-- The first attribute below should be the issue id; makes it easier to navigate in the IDE outline -->
 
+      <action issue="CODEC-232" dev="sebb" type="fix">URLCodec is neither immutable nor threadsafe</action>
       <action issue="CODEC-231" dev="sebb" type="fix">StringUtils.equals(CharSequence cs1, CharSequence cs2) can fail with String Index OBE</action>
       <action issue="CODEC-230" dev="sebb" type="fix">URLCodec.WWW_FORM_URL should be private</action>
       <action issue="CODEC-229" dev="sebb" type="fix">StringUtils.newStringxxx(null) should return null, not NPE</action>

src/main/java/org/apache/commons/codec/net/URLCodec.java

@@ -37,7 +37,7 @@
  * {@link java.net.URLDecoder} on older Java platforms, as these classes in Java versions below
  * 1.4 rely on the platform's default charset encoding.
  * <p>
- * This class is immutable and thread-safe.
+ * This class is thread-safe since 1.11
  *
  * @see <a href="http://www.w3.org/TR/html4/interact/forms.html#h-17.13.4.1">Chapter 17.13.4 Form content types</a>
  *           of the <a href="http://www.w3.org/TR/html4/">HTML 4.01 Specification</a>
@@ -53,7 +53,7 @@ public class URLCodec implements BinaryEncoder, BinaryDecoder, StringEncoder, St
      * @deprecated TODO: This field will be changed to a private final Charset in 2.0. (CODEC-126)
      */
     @Deprecated
-    protected String charset;
+    protected volatile String charset; // added volatile: see CODEC-232
 
     /**
      * Release 1.5 made this field final.
@@ -62,7 +62,9 @@ public class URLCodec implements BinaryEncoder, BinaryDecoder, StringEncoder, St
 
     /**
      * BitSet of www-form-url safe characters.
-     * @deprecated Will be removed in 2.0 (CODEC-230)
+     * This is a copy of the internal BitSet which is now used for the conversion.
+     * Changes to this field are ignored.
+     * @deprecated 1.11 Will be removed in 2.0 (CODEC-230)
      */
     @Deprecated
     protected static final BitSet WWW_FORM_URL;