More defensive guards against invalid code points in ant Preferences

Once the Preferences is loaded containing U+0000 in a key, it can't
be used anymore since even removing that key (e.g via clear()) will
throw IAE.

What we can do however is to remove and recreate the Preferences node.

Author: mbien

extide/o.apache.tools.ant.module/src/org/apache/tools/ant/module/AntSettings.java

@@ -31,6 +31,7 @@
 import java.util.TreeMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import java.util.prefs.BackingStoreException;
 import java.util.prefs.Preferences;
 import java.util.regex.Pattern;
 import org.apache.tools.ant.module.api.IntrospectedInfo;
@@ -122,7 +123,27 @@ public static synchronized IntrospectedInfo getCustomDefs() {
     }
 
     public static synchronized void setCustomDefs(IntrospectedInfo ii) {
-        IntrospectedInfoSerializer.instance.store(prefs().node(PROP_CUSTOM_DEFS), ii);
+        Preferences prefs = prefs();
+        Preferences node = prefs.node(PROP_CUSTOM_DEFS);
+        try {
+            IntrospectedInfoSerializer.instance.store(node, ii);
+        } catch (IllegalArgumentException iae) {
+            // recreate node in case of corrupted files. Once Preferences are loaded,
+            // keys which contain code point U+0000 can't be used anymore (clear() will also fail)
+            if (iae.getMessage().contains("U+0000")) {
+                LOG.log(Level.WARNING, "recreating {0} preferences node due to code point U+0000", PROP_CUSTOM_DEFS);
+                try {
+                    node.removeNode();
+                    prefs.flush();
+                    node = prefs.node(PROP_CUSTOM_DEFS);
+                    IntrospectedInfoSerializer.instance.store(node, ii);
+                } catch (BackingStoreException bse) {
+                    throw new RuntimeException("can't write to preferences", bse);
+                }
+            } else {
+                throw iae;
+            }
+        }
         customDefs = ii;
     }
 

extide/o.apache.tools.ant.module/src/org/apache/tools/ant/module/api/IntrospectedInfo.java

@@ -683,21 +683,21 @@ public IntrospectedInfo load(Preferences node) {
                         try {
                             v = node.get(k, null);
                         } catch (IllegalArgumentException ex) { // e.g invalid code point JDK-8075156
-                            LOG.log(Level.WARNING, "malformed key: {0}, pref path: {1}, msg: {2}",
-                                    new Object[] {k, node.absolutePath(), ex.getMessage()});
+                            LOG.log(Level.WARNING, "skipping malformed key; pref path: {0}, msg: {1}",
+                                    new Object[] {node.absolutePath(), ex.getMessage()});
                             continue;
                         }
                         assert v != null : k;
                         String[] ss = k.split("\\.", 2);
                         if (ss.length != 2) {
-                            LOG.log(Level.WARNING, "malformed key: {0}, pref path: {1}", new Object[] {k, node.absolutePath()});
+                            LOG.log(Level.WARNING, "skipping malformed key: {0}, pref path: {1}", new Object[] {k, node.absolutePath()});
                             continue;
                         }
                         if (ss[0].equals("class")) {
                             Matcher m = p.matcher(ss[1]);
                             boolean match = m.matches();
                             if (!match) {
-                                LOG.log(Level.WARNING, "malformed key: {0}, pref path: {1}", new Object[] {k, node.absolutePath()});
+                                LOG.log(Level.WARNING, "skipping malformed key: {0}, pref path: {1}", new Object[] {k, node.absolutePath()});
                                 continue;
                             }
                             String c = m.group(1);