Send 404 if Git label not found

See gh-153

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/EnvironmentController.java

@@ -186,6 +186,11 @@ public class EnvironmentController {
 		return result == null ? new LinkedHashMap<String, Object>() : result;
 	}
 
+	@ExceptionHandler(NoSuchLabelException.class)
+	public void noSuchLabel(HttpServletResponse response) throws IOException {
+		response.sendError(HttpStatus.NOT_FOUND.value());
+	}
+
 	@ExceptionHandler(IllegalArgumentException.class)
 	public void illegalArgument(HttpServletResponse response) throws IOException {
 		response.sendError(HttpStatus.BAD_REQUEST.value());

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/JGitEnvironmentRepository.java

@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.List;
 
 import com.jcraft.jsch.Session;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.eclipse.jgit.api.CheckoutCommand;
@@ -33,13 +34,13 @@ import org.eclipse.jgit.api.ListBranchCommand.ListMode;
 import org.eclipse.jgit.api.PullCommand;
 import org.eclipse.jgit.api.TransportCommand;
 import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.api.errors.RefNotFoundException;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.transport.JschConfigSessionFactory;
 import org.eclipse.jgit.transport.OpenSshConfig.Host;
 import org.eclipse.jgit.transport.SshSessionFactory;
 import org.eclipse.jgit.transport.UsernamePasswordCredentialsProvider;
 import org.eclipse.jgit.util.FileUtils;
-
 import org.springframework.cloud.config.environment.Environment;
 import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.io.UrlResource;
@@ -79,8 +80,11 @@ public class JGitEnvironmentRepository extends AbstractScmEnvironmentRepository
 			git = createGitClient();
 			return loadEnvironment(git, application, profile, label);
 		}
+		catch (RefNotFoundException e) {
+			throw new NoSuchLabelException("No such label: " + label);
+		}
 		catch (GitAPIException e) {
-			throw new IllegalStateException("Cannot clone repository", e);
+			throw new IllegalStateException("Cannot clone or checkout repository", e);
 		}
 		catch (Exception e) {
 			throw new IllegalStateException("Cannot load environment", e);

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/NativeEnvironmentRepository.java

@@ -94,8 +94,7 @@ public class NativeEnvironmentRepository implements EnvironmentRepository {
 		builder.web(false).showBanner(false);
 		String[] args = getArgs(config, label);
 		// Explicitly set the listeners (to exclude logging listener which would change
-		// log
-		// levels in the caller)
+		// log levels in the caller)
 		builder.application().setListeners(
 				Collections.singletonList(new ConfigFileApplicationListener()));
 		ConfigurableApplicationContext context = builder.run(args);

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/NoSuchLabelException.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.config.server;
+
+/**
+ * @author Dave Syer
+ *
+ */
+@SuppressWarnings("serial")
+public class NoSuchLabelException extends RepositoryException {
+
+	public NoSuchLabelException(String string) {
+		super(string);
+	}
+
+}

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/RepositoryException.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.config.server;
+
+/**
+ * @author Dave Syer
+ *
+ */
+@SuppressWarnings("serial")
+public class RepositoryException extends RuntimeException {
+
+	public RepositoryException(String string) {
+		super(string);
+	}
+
+}

spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/JGitEnvironmentRepositoryIntegrationTests.java

@@ -122,7 +122,7 @@ public class JGitEnvironmentRepositoryIntegrationTests {
 		assertEquals("master", repository.getDefaultLabel());
 	}
 
-	@Test(expected = IllegalStateException.class)
+	@Test(expected = NoSuchLabelException.class)
 	public void invalidLabel() throws IOException {
 		String uri = ConfigServerTestUtils.prepareLocalRepo();
 		context = new SpringApplicationBuilder(TestConfiguration.class).web(false)