[cp-patches] FYI: Avoid recursion in java.util.Properties

[Roman Kennke]

This fix 'outsources' the functionality of the getProperty methods into 
a private method. This avoids infinite recursion if one of the 
getProperty methods is overridden in subclasses.

2005-07-26  Roman Kennke  <address@hidden>

        * java/util/Properties.java
        (getPropertyInternal): New method. Avoids infinite recursion if
        getProperty() methods are overridden in subclasses.
        (getProperty(String)): Use getPropertyInternal to avoid recursion.
        (getProperty(String,String)): Likewise.

/Roman

Index: java/util/Properties.java
===================================================================
RCS file: /cvsroot/classpath/classpath/java/util/Properties.java,v
retrieving revision 1.30
diff -u -r1.30 Properties.java
--- java/util/Properties.java   25 Jul 2005 17:42:38 -0000      1.30
+++ java/util/Properties.java   26 Jul 2005 14:22:22 -0000
@@ -398,6 +398,30 @@
 
     writer.flush ();
   }
+  
+  /**
+   *  Internal method called by getProperty() methods. This avoids 
+   *  recursive calls if getProperty() methods are overwritten in 
+   *  a subclass.
+   *
+   * @param key the key for the property to fetch
+   * @param defaultValue the defaultValue or <code>null</code> if there
+   *        is no default value
+   */
+  private String getPropertyInternal(String key, String defaultValue)
+  {
+    Properties prop = this;
+    // Eliminate tail recursion.
+    do
+      {
+        String value = (String) prop.get(key);
+        if (value != null)
+          return value;
+        prop = prop.defaults;
+      }
+    while (prop != null);
+    return defaultValue;    
+  }
 
   /**
    * Gets the property with the specified key in this property list.
@@ -414,7 +438,7 @@
    */
   public String getProperty(String key)
   {
-    return getProperty(key, null);
+    return getPropertyInternal(key, null);
   }
 
   /**
@@ -433,17 +457,7 @@
    */
   public String getProperty(String key, String defaultValue)
   {
-    Properties prop = this;
-    // Eliminate tail recursion.
-    do
-      {
-        String value = (String) prop.get(key);
-        if (value != null)
-          return value;
-        prop = prop.defaults;
-      }
-    while (prop != null);
-    return defaultValue;
+    return getPropertyInternal(key, defaultValue);
   }
 
   /**