disable the creation of TTL indexes on sub-attributes (#9995)

* disable the creation of TTL indexes on sub-attributes

* updated CHANGELOG

CHANGELOG

@@ -1,6 +1,12 @@
 v3.5.1 (XXXX-XX-XX)
 -------------------
 
+* Disallow creation of TTL indexes on sub-attributes.
+
+  Creation of such indexes was not caught before, but the resulting 
+  indexes were defunct. From now on the creation of TTL indexes on sub-
+  attributes is disallowed.
+
 * Added HotBackup feature.
 
 * Improved database creation within the cluster. In the case of

arangod/Indexes/IndexFactory.cpp

@@ -333,7 +333,9 @@ TRI_idx_iid_t IndexFactory::validateSlice(arangodb::velocypack::Slice info,
   return iid;
 }
 
-Result IndexFactory::validateFieldsDefinition(VPackSlice definition, size_t minFields, size_t maxFields) {
+Result IndexFactory::validateFieldsDefinition(VPackSlice definition, 
+                                              size_t minFields, size_t maxFields,
+                                              bool allowSubAttributes) {
   if (basics::VelocyPackHelper::getBooleanValue(definition, StaticStrings::Error, false)) {
     // We have an error here.
     return Result(TRI_ERROR_BAD_PARAMETER);
@@ -364,7 +366,12 @@ Result IndexFactory::validateFieldsDefinition(VPackSlice definition, size_t minF
         return Result(TRI_ERROR_BAD_PARAMETER,
                       "duplicate attribute name in index fields list");
       }
-      
+
+      if (!allowSubAttributes && f.find('.') != std::string::npos) { 
+        return Result(TRI_ERROR_BAD_PARAMETER,
+                      "cannot index a sub-attribute in this type of index");
+      }
+
       if (std::regex_match(f.toString(), idRegex)) {
         return Result(TRI_ERROR_BAD_PARAMETER,
                       "_id attribute cannot be indexed");
@@ -386,10 +393,11 @@ Result IndexFactory::validateFieldsDefinition(VPackSlice definition, size_t minF
 /// @brief process the fields list, deduplicate it, and add it to the json
 Result IndexFactory::processIndexFields(VPackSlice definition, VPackBuilder& builder,
                                         size_t minFields, size_t maxFields,
-                                        bool create, bool allowExpansion) {
+                                        bool create, bool allowExpansion,
+                                        bool allowSubAttributes) {
   TRI_ASSERT(builder.isOpenObject());
 
-  Result res = validateFieldsDefinition(definition, minFields, maxFields);
+  Result res = validateFieldsDefinition(definition, minFields, maxFields, allowSubAttributes);
   if (res.fail()) {
     return res;
   }
@@ -477,7 +485,7 @@ Result IndexFactory::enhanceJsonIndexGeneric(VPackSlice definition,
 /// @brief enhances the json of a ttl index
 Result IndexFactory::enhanceJsonIndexTtl(VPackSlice definition,
                                          VPackBuilder& builder, bool create) {
-  Result res = processIndexFields(definition, builder, 1, 1, create, false);
+  Result res = processIndexFields(definition, builder, 1, 1, create, false, false);
   
   auto value = definition.get(arangodb::StaticStrings::IndexUnique);
   if (value.isBoolean() && value.getBoolean()) {

arangod/Indexes/IndexFactory.h

@@ -111,13 +111,14 @@ class IndexFactory {
                               std::vector<std::shared_ptr<arangodb::Index>>& indexes) const = 0;
 
   static Result validateFieldsDefinition(arangodb::velocypack::Slice definition, 
-                                         size_t minFields, size_t maxFields);
+                                         size_t minFields, size_t maxFields,
+                                         bool allowSubAttributes = true);
 
   /// @brief process the fields list, deduplicate it, and add it to the json
   static Result processIndexFields(arangodb::velocypack::Slice definition, 
                                    arangodb::velocypack::Builder& builder,
                                    size_t minFields, size_t maxFields, bool create,
-                                   bool allowExpansion);
+                                   bool allowExpansion, bool allowSubAttributes = true);
 
   /// @brief process the unique flag and add it to the json
   static void processIndexUniqueFlag(arangodb::velocypack::Slice definition,

tests/js/common/shell/shell-ttl.js

@@ -204,6 +204,16 @@ function TtlSuite () {
       // number of runs must not have changed
       assertEqual(stats.runs, oldRuns);
     },
+    
+    testCreateIndexSubAttribute : function () {
+      let c = db._create(cn, { numberOfShards: 2 });
+      try {
+        c.ensureIndex({ type: "ttl", fields: ["date.created"], expireAfter: 10, unique: true });
+        fail();
+      } catch (err) {
+        assertEqual(ERRORS.ERROR_BAD_PARAMETER.code, err.errorNum);
+      }
+    },
 
     testCreateIndexUnique : function () {
       let c = db._create(cn, { numberOfShards: 2 });