Return 204 No Content on DELETE /projects/*/description

When a description is deleted the key is removed from the
configuration file. Callers should expect a 204 response.

For any PUT response return the same as GET, which is ""
instead of the literal word "null" if there is no text
after the put is complete.

Change-Id: I2ba174d1129a14d862c2b26da5eb8bebc0671f63

gerrit-server/src/main/java/com/google/gerrit/server/project/Module.java

@@ -31,8 +31,8 @@ public class Module extends RestApiModule {
 
     get(PROJECT_KIND).to(GetProject.class);
     get(PROJECT_KIND, "description").to(GetDescription.class);
-    put(PROJECT_KIND, "description").to(SetDescription.class);
+    put(PROJECT_KIND, "description").to(PutDescription.class);
-    delete(PROJECT_KIND, "description").to(SetDescription.class);
+    delete(PROJECT_KIND, "description").to(PutDescription.class);
 
     get(PROJECT_KIND, "parent").to(GetParent.class);
     put(PROJECT_KIND, "parent").to(SetParent.class);

gerrit-server/src/main/java/com/google/gerrit/server/project/PutDescription.java

@@ -21,19 +21,22 @@ import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.DefaultInput;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
+import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.git.MetaDataUpdate;
 import com.google.gerrit.server.git.ProjectConfig;
-import com.google.gerrit.server.project.SetDescription.Input;
+import com.google.gerrit.server.project.PutDescription.Input;
 import com.google.inject.Inject;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
 
-class SetDescription implements RestModifyView<ProjectResource, Input> {
+import java.io.IOException;
+
+class PutDescription implements RestModifyView<ProjectResource, Input> {
   static class Input {
     @DefaultInput
     String description;
@@ -45,7 +48,7 @@ class SetDescription implements RestModifyView<ProjectResource, Input> {
   private final GitRepositoryManager gitMgr;
 
   @Inject
-  SetDescription(ProjectCache cache,
+  PutDescription(ProjectCache cache,
       MetaDataUpdate.Server updateFactory,
       GitRepositoryManager gitMgr) {
     this.cache = cache;
@@ -54,11 +57,13 @@ class SetDescription implements RestModifyView<ProjectResource, Input> {
   }
 
   @Override
-  public String apply(ProjectResource resource, Input input)
+  public Response<String> apply(ProjectResource resource, Input input)
       throws AuthException, BadRequestException, ResourceConflictException,
-      Exception {
+      ResourceNotFoundException, IOException {
+    boolean delete = false;
     if (input == null) {
       input = new Input(); // Delete would set description to null.
+      delete = true;
     }
 
     ProjectControl ctl = resource.getControl();
@@ -88,7 +93,10 @@ class SetDescription implements RestModifyView<ProjectResource, Input> {
             resource.getNameKey(),
             project.getDescription());
 
-        return project.getDescription();
+        if (delete) {
+          return Response.none();
+        }
+        return Response.ok(Strings.nullToEmpty(project.getDescription()));
       } finally {
         md.close();
       }