testing: added test case for add<->add conflict (part of BMC #22783)

The test can be used in combination with a SyncEvolution HTTP server
or local sync. Currently doesn't pass because a libsynthesis with
support for DB_DataMerged is needed.

src/syncevo/SyncSource.cpp

@@ -668,6 +668,9 @@ sysync::TSyError SyncSourceSerialize::insertItemAsKey(sysync::KeyH aItemKey, sys
         InsertItemResult inserted =
             insertItem(!aID ? "" : aID->item, data.get());
         newID->item = StrAlloc(inserted.m_luid.c_str());
+        if (inserted.m_merged) {
+            res = sysync::DB_DataMerged;
+        }
     }
 
     return res;

test/ClientTest.cpp

@@ -1811,6 +1811,11 @@ void SyncTests::addTests(bool isFirstSource) {
                     ADD_TEST(SyncTests, testSlowSyncSemantic);
                     ADD_TEST(SyncTests, testComplexRefreshFromServerSemantic);
                     ADD_TEST(SyncTests, testDeleteBothSides);
+                    if (config.m_updateItem.find("UID:") != std::string::npos &&
+                        config.m_updateItem.find("LAST-MODIFIED:") != std::string::npos &&
+                        sources.size() == 1) {
+                        ADD_TEST(SyncTests, testAddBothSides);
+                    }
 
                     // only add when testing individual source,
                     // test data not guaranteed to be available for all sources
@@ -3072,6 +3077,67 @@ void SyncTests::testDeleteBothSides()
     }
 }
 
+/**
+ * - clean A, server, B
+ * - create an item on A
+ * - sync A
+ * - create a modified version of the item on B
+ * - sync B
+ *
+ * Depends on UID and LAST-MODIFIED in item data, i.e., iCalendar 2.0.
+ * Uses the normal "insertItem" test case. Only works for a single source.
+ *
+ * The server must not duplicate the item *and* preserve the modified
+ * properties.
+ *
+ * A similar situation occurs on the client side, but it is harder to
+ * trigger: the updated item must be added to the client's database
+ * after it has reported its changes. Because if it happens earlier,
+ * it would send an Add to the server and the server would have to
+ * resolve the add<->add conflict, as in this test here.
+ */
+void SyncTests::testAddBothSides()
+{
+    deleteAll();
+    accessClientB->deleteAll();
+
+    CPPUNIT_ASSERT_NO_THROW(sources[0].second->insert(sources[0].second->createSourceA,
+                                                      sources[0].second->config.m_insertItem));
+
+    doSync("send-old",
+           SyncOptions(SYNC_TWO_WAY,
+                       CheckSyncReport(0,0,0, 1,0,0, true, SYNC_TWO_WAY)));
+
+    // insert updated item data on B
+    std::string data;
+    CPPUNIT_ASSERT_NO_THROW(accessClientB->sources[0].second->insert(accessClientB->sources[0].second->createSourceA,
+                                                                     accessClientB->sources[0].second->config.m_updateItem,
+                                                                     false,
+                                                                     &data));
+
+    // as far as the client knows, it is adding an item;
+    // server not expected to send back an update (our data was more recent)
+    accessClientB->doSync("send-update",
+                          SyncOptions(SYNC_TWO_WAY,
+                                      CheckSyncReport(0,0,0, 1,0,0, true, SYNC_TWO_WAY)));
+
+    // update sent to client A
+    doSync("update",
+           SyncOptions(SYNC_TWO_WAY,
+                       CheckSyncReport(0,1,0, 0,0,0, true, SYNC_TWO_WAY)));
+
+    // nothing necessary for client B
+    accessClientB->doSync("nop",
+                          SyncOptions(SYNC_TWO_WAY,
+                                      CheckSyncReport(0,0,0, 0,0,0, true, SYNC_TWO_WAY)));
+
+    // now compare client A against reference data
+    TestingSyncSourcePtr copy;
+    SOURCE_ASSERT_NO_FAILURE(copy.get(), copy.reset(sources[0].second->createSourceB()));
+    sources[0].second->compareDatabases(*copy, &data, (void *)NULL);
+    CPPUNIT_ASSERT_NO_THROW(copy.reset());
+}
+
 /**
  * - adds parent on client A
  * - syncs A

test/ClientTest.h

@@ -753,6 +753,7 @@ protected:
     virtual void testSlowSyncSemantic();
     virtual void testComplexRefreshFromServerSemantic();
     virtual void testDeleteBothSides();
+    virtual void testAddBothSides();
     virtual void testLinkedItemsParentChild();
     virtual void testLinkedItemsChild();
     virtual void testLinkedItemsChildParent();