Mapper is not added to known mapper when it fails to configure.

Author: christianpoitras

src/main/java/org/apache/ibatis/binding/MapperRegistry.java

@@ -35,12 +35,20 @@ public void addMapper(Class<?> type) {
       if (knownMappers.contains(type)) {
         throw new BindingException("Type " + type + " is already known to the MapperRegistry.");
       }
-      knownMappers.add(type);
-      // It's important that the type is added before the parser is run
-      // otherwise the binding may automatically be attempted by the
-      // mapper parser.  If the type is already known, it won't try.
-      MapperAnnotationBuilder parser = new MapperAnnotationBuilder(config, type);
-      parser.parse();
+      boolean loadCompleted = false;
+      try {
+        knownMappers.add(type);
+        // It's important that the type is added before the parser is run
+        // otherwise the binding may automatically be attempted by the
+        // mapper parser.  If the type is already known, it won't try.
+        MapperAnnotationBuilder parser = new MapperAnnotationBuilder(config, type);
+        parser.parse();
+        loadCompleted = true;
+      } finally {
+        if (!loadCompleted) {
+          knownMappers.remove(type);
+        }
+      }
     }
   }
 }

src/main/java/org/apache/ibatis/builder/annotation/MapperAnnotationBuilder.java

@@ -85,8 +85,8 @@ public MapperAnnotationBuilder(Configuration configuration, Class<?> type) {
   public void parse() {
     String resource = type.toString();
     if (!configuration.isResourceLoaded(resource)) {
-      configuration.addLoadedResource(resource);
       loadXmlResource();
+      configuration.addLoadedResource(resource);
       assistant.setCurrentNamespace(type.getName());
       parseCache();
       parseCacheRef();

src/main/java/org/apache/ibatis/builder/xml/XMLMapperBuilder.java

@@ -47,8 +47,8 @@ public XMLMapperBuilder(Reader reader, Configuration configuration, String resou
 
   public void parse() {
     if (!configuration.isResourceLoaded(resource)) {
-      configuration.addLoadedResource(resource);
       configurationElement(parser.evalNode("/mapper"));
+      configuration.addLoadedResource(resource);
       bindMapperForNamespace();
     }
   }