Fix errant “accept anything” handling of providers

cbor/src/main/java/tools/jackson/jaxrs/cbor/JacksonCBORProvider.java

@@ -138,10 +138,8 @@ protected boolean hasMatchingMediaType(MediaType mediaType)
             return CBORMediaTypes.APPLICATION_JACKSON_CBOR_TYPE.getSubtype().equalsIgnoreCase(subtype) || 
             		"cbor".equalsIgnoreCase(subtype) || subtype.endsWith("+cbor");
         }
-        /* Not sure if this can happen; but it seems reasonable
-         * that we can at least produce CBOR without media type?
-         */
-        return true;
+        // Without a media type, let JAX-RS deal with mapping if it can.
+        return false;
     }
 
     /**

json/src/main/java/tools/jackson/jaxrs/json/JacksonJsonProvider.java

@@ -167,9 +167,8 @@ protected boolean hasMatchingMediaType(MediaType mediaType)
                    || "x-json".equals(subtype) // [Issue#40]
                    ;
         }
-        // Not sure if this can happen; but it seems reasonable
-        // that we can at least produce JSON without media type?
-        return true;
+        // Without a media type, let JAX-RS deal with mapping if it can.
+        return false;
     }
 
     @Override

smile/src/main/java/tools/jackson/jaxrs/smile/JacksonSmileProvider.java

@@ -137,10 +137,8 @@ protected boolean hasMatchingMediaType(MediaType mediaType)
             return SmileMediaTypes.APPLICATION_JACKSON_SMILE_TYPE.getSubtype().equalsIgnoreCase(subtype) || 
             		"smile".equalsIgnoreCase(subtype) || subtype.endsWith("+smile");
         }
-        /* Not sure if this can happen; but it seems reasonable
-         * that we can at least produce smile without media type?
-         */
-        return true;
+        // Without a media type, let JAX-RS deal with mapping if it can.
+        return false;
     }
 
     /**

xml/src/main/java/tools/jackson/jaxrs/xml/JacksonXMLProvider.java

@@ -143,10 +143,8 @@ protected boolean hasMatchingMediaType(MediaType mediaType)
             String subtype = mediaType.getSubtype();
             return "xml".equalsIgnoreCase(subtype) || subtype.endsWith("+xml");
         }
-        /* Not sure if this can happen; but it seems reasonable
-         * that we can at least produce XML without media type?
-         */
-        return true;
+        // Without a media type, let JAX-RS deal with mapping if it can.
+        return false;
     }
 
     /**

xml/src/test/java/tools/jackson/jaxrs/xml/TestUntouchables.java

@@ -6,8 +6,6 @@
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.StreamingOutput;
 
-import tools.jackson.jaxrs.xml.JacksonXMLProvider;
-
 /**
  * Unit tests for verifying that certain JDK base types will be
  * ignored by default Jackson JAX-RS conversion provider.
@@ -20,7 +18,7 @@ public class TestUntouchables
      * remains overridable.
      */
     public static class MyJacksonProvider extends JacksonXMLProvider {
-         // ensure isJsonType remains "protected" � this is a compile-time check.
+         // ensure isJsonType remains "protected" this is a compile-time check.
          // Some users of JacksonJsonProvider override this method;
          // changing to "private" would regress them.
          @Override

yaml/src/main/java/tools/jackson/jaxrs/yaml/JacksonYAMLProvider.java

@@ -154,10 +154,8 @@ protected boolean hasMatchingMediaType(MediaType mediaType) {
             return "yaml".equalsIgnoreCase(subtype) || subtype.endsWith("+yaml");
             //tarik: apparently there is not a standard for yaml types, should be discussed
         }
-        /* Not sure if this can happen; but it seems reasonable
-         * that we can at least produce yaml without media type?
-         */
-        return true;
+        // Without a media type, let JAX-RS deal with mapping if it can.
+        return false;
     }
 
     /**