Fix deleted revision bug:

Fetching attachments on a deleted revision would
cause an exception to be thrown. Fix and add test
for this.

Author: Tom Blench

cloudant-sync-datastore-core/src/main/java/com/cloudant/sync/internal/documentstore/callables/DeleteDocumentCallable.java

@@ -14,10 +14,10 @@
 
 package com.cloudant.sync.internal.documentstore.callables;
 
+import com.cloudant.sync.documentstore.Attachment;
 import com.cloudant.sync.documentstore.ConflictException;
 import com.cloudant.sync.documentstore.DocumentStoreException;
 import com.cloudant.sync.internal.common.CouchUtils;
-import com.cloudant.sync.internal.documentstore.DatabaseImpl;
 import com.cloudant.sync.documentstore.DocumentBodyFactory;
 import com.cloudant.sync.documentstore.DocumentNotFoundException;
 import com.cloudant.sync.internal.documentstore.InternalDocumentRevision;
@@ -30,6 +30,7 @@
 import com.cloudant.sync.internal.util.Misc;
 
 import java.sql.SQLException;
+import java.util.Collections;
 
 /**
  * Delete a Document for given Document ID and Revision ID.
@@ -125,6 +126,7 @@ public InternalDocumentRevision call(SQLDatabase db) throws ConflictException,
                 .setCurrent(current)
                 .setBody(DocumentBodyFactory.create(JSONUtils.emptyJSONObjectAsBytes()))
                 .setSequence(newSequence)
+                .setAttachments(Collections.<String, Attachment>emptyMap())
                 .build();
     }
 

cloudant-sync-datastore-core/src/test/java/com/cloudant/sync/internal/documentstore/AttachmentTest.java

@@ -23,8 +23,10 @@
 import com.cloudant.sync.documentstore.AttachmentException;
 import com.cloudant.sync.documentstore.AttachmentNotSavedException;
 import com.cloudant.sync.documentstore.ConflictException;
+import com.cloudant.sync.documentstore.DocumentBodyFactory;
 import com.cloudant.sync.documentstore.DocumentException;
 import com.cloudant.sync.documentstore.DocumentRevision;
+import com.cloudant.sync.documentstore.DocumentStore;
 import com.cloudant.sync.documentstore.UnsavedFileAttachment;
 import com.cloudant.sync.documentstore.UnsavedStreamAttachment;
 import com.cloudant.sync.documentstore.encryption.NullKeyProvider;
@@ -45,6 +47,7 @@
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.regex.Matcher;
@@ -411,4 +414,54 @@ public void attachmentOrderingTest() throws Exception {
         Matcher m = p.matcher(regex);
         Assert.assertTrue("Should match pattern", m.matches());
     }
+
+    // test for regression on fetching attachments after deleting revision which previously had no
+    // attachments
+    @Test
+    public void getAttachmentsOnDeletedRevisionNoAttachments() throws Exception {
+
+        DocumentRevision revision = new DocumentRevision();
+        Map<String, Object> body = new HashMap<String, Object>();
+        body.put("animal", "cat");
+        revision.setBody(DocumentBodyFactory.create(body));
+
+        // create rev
+        DocumentRevision saved = documentStore.database().create(revision);
+        Map<String, Attachment> attachments = saved.getAttachments();
+        Assert.assertTrue(attachments.isEmpty());
+
+        DocumentRevision deleted = documentStore.database().delete(saved);
+        attachments = deleted.getAttachments();
+
+        Assert.assertTrue(attachments.isEmpty());
+    }
+
+
+    // test for regression on fetching attachments after deleting revision which previously had some
+    // attachments
+    @Test
+    public void getAttachmentsOnDeletedRevisionSomeAttachments() throws Exception {
+
+        DocumentRevision revision = new DocumentRevision();
+        Map<String, Object> body = new HashMap<String, Object>();
+        body.put("animal", "cat");
+        revision.setBody(DocumentBodyFactory.create(body));
+
+        // add attachment
+        String imageAttachmentName = "bonsai-boston.jpg";
+        File imageFile = TestUtils.loadFixture("fixture/" + imageAttachmentName);
+        Attachment att = new UnsavedFileAttachment(imageFile, "image/jpeg");
+        revision.getAttachments().put(imageAttachmentName, att);
+
+        //create rev
+        DocumentRevision saved = documentStore.database().create(revision);
+        Map<String, Attachment> attachments = saved.getAttachments();
+        Assert.assertEquals(attachments.size(), 1);
+
+        DocumentRevision deleted = documentStore.database().delete(saved);
+        attachments = deleted.getAttachments();
+
+        Assert.assertTrue(attachments.isEmpty());
+    }
+
 }