diff --git a/src/lib/diff/record-content-mutator.hpp b/src/lib/diff/record-content-mutator.hpp
index c46299f9b..05b79dfee 100644
--- a/src/lib/diff/record-content-mutator.hpp
+++ b/src/lib/diff/record-content-mutator.hpp
@@ -51,6 +51,7 @@
 namespace lib {
 namespace diff{
   
+  namespace error = lumiera::error;
   using std::move;
   using std::swap;
   
@@ -77,19 +78,21 @@ namespace diff{
       empty()  const
         {
           return attribs.empty()
-              && children.empty();
+             and children.empty();
         }
       
       bool
       currIsAttrib()  const
         {
-          UNIMPLEMENTED ("determine current scope");
+          return & *pos >= & *attribs.begin()
+             and & *pos <  & *attribs.end();
         }
       
       bool
       currIsChild()  const
         {
-          UNIMPLEMENTED ("determine current scope");
+          return & *pos >= & *children.begin()
+             and & *pos <  & *children.end();
         }
       
       Iter end()        { return children.end(); }
@@ -98,7 +101,16 @@ namespace diff{
       RecordContentMutator&
       operator++()
         {
-          UNIMPLEMENTED ("iteration");
+          if (pos == children.end())
+            throw error::State ("attempt to iterate beyond end of scope"
+                               ,error::LUMIERA_ERROR_ITER_EXHAUST);
+          if (pos == attribs.end())
+            pos = children.begin();
+          else
+            ++pos;
+          if (pos == attribs.end())
+            pos = children.begin();
+          return *this;
         }
       
       void
diff --git a/src/lib/diff/record.hpp b/src/lib/diff/record.hpp
index 491091509..7fe87d1e0 100644
--- a/src/lib/diff/record.hpp
+++ b/src/lib/diff/record.hpp
@@ -463,6 +463,7 @@ namespace diff{
                                               record_.children_.size());
           std::swap (record_.attribs_, alteredContent.attribs);
           std::swap (record_.children_, alteredContent.children);
+          alteredContent.resetPos();
         }
       
       /* === extension point for building specific value types === */
diff --git a/tests/15library.tests b/tests/15library.tests
index 927327069..5a66af384 100644
--- a/tests/15library.tests
+++ b/tests/15library.tests
@@ -243,7 +243,12 @@ return: 0
 END
 
 
-TEST "GenNodeBasic_test" GenNodeBasic_test <<END
+TEST "Generic Record - Mutations" GenericRecordUpdate_test <<END
+return: 0
+END
+
+
+TEST "Generic Record data node" GenNodeBasic_test <<END
 out-lit: GenNode-ID("_CHILD_Record.001")-DataCap|«lib::diff::Record<lib::diff::GenNode>»|Rec(spam| ham = DataCap|«std::string»|eggs |{})
 out-lit: --spam--
 out-lit: GenNode-ID("baked beans")-DataCap|«lib::diff::Record<lib::diff::GenNode>»|Rec(hasSpam = DataCap|«bool»|1 |{GenNode-ID("_CHILD_char.002")-DataCap|«char»|*, GenNode-ID("_CHILD_string.006")-DataCap|«std::string»|★, GenNode-ID("_CHILD_double.001")-DataCap|«double»|3.1415926535897931, GenNode-ID("spam")-DataCap|«lib::diff::Record<lib::diff::GenNode>»|Rec(ham|  |{GenNode-ID("_CHILD_string.003")-DataCap|«std::string»|eggs, GenNode-ID("_CHILD_string.004")-DataCap|«std::string»|spam, GenNode-ID("_CHILD_string.005")-DataCap|«std::string»|spam}), GenNode-ID("_CHILD_TimeSpan.002")-DataCap|«lib::time::TimeSpan»|0:00:00.000[920ms], GenNode-ID("_CHILD_long.001")-DataCap|«long»|42})
diff --git a/tests/library/diff/generic-record-update-test.cpp b/tests/library/diff/generic-record-update-test.cpp
index 2767982a8..582e210da 100644
--- a/tests/library/diff/generic-record-update-test.cpp
+++ b/tests/library/diff/generic-record-update-test.cpp
@@ -24,9 +24,7 @@
 #include "lib/test/run.hpp"
 #include "lib/test/test-helper.hpp"
 #include "lib/diff/record-content-mutator.hpp"
-//#include "lib/iter-adapter-stl.hpp"
-//#include "lib/time/timevalue.hpp"
-//#include "lib/format-util.hpp"
+#include "lib/format-util.hpp"
 #include "lib/diff/record.hpp"
 #include "lib/itertools.hpp"
 #include "lib/util.hpp"
@@ -34,15 +32,10 @@
 #include <algorithm>
 #include <string>
 #include <vector>
-#include <iostream> ///TODO
 
-//using lib::iter_stl::snapshot;
 using lib::append_all;
 using util::isnil;
-//using util::join;
-//using std::string;
 using std::vector;
-//using lib::time::Time;
 
 using lumiera::error::LUMIERA_ERROR_ITER_EXHAUST;
 
@@ -71,7 +64,6 @@ namespace test{
       return contents (rec_of_strings.begin());
     }
     
-    
   }//(End)Test fixture
   
   
@@ -90,7 +82,7 @@ namespace test{
    *       which are by default immutable. Thus, for this specific task, embedded
    *       data is moved into this adapter, which exposes the mutating operation
    *       required to apply such a diff message.
-   *       
+   * 
    * @see generic-record-representation-test.cpp
    * @see tree-diff-application-test.cpp
    */
@@ -105,13 +97,12 @@ namespace test{
           RecS::Mutator mut(subject);
           mut.appendChild("δ");
           mut.setType("🌰");
-          std::cout << string(subject) << std::endl;
           
-          RecS::ContentMutator content;
+          RecS::ContentMutator content; // empty
           
           CHECK (!isnil (mut));
           CHECK ( isnil (content));
-          mut.swapContent(content);
+          mut.swapContent(content); // contents of mutator now moved over
           CHECK (!isnil (content));
           CHECK ( isnil (mut));
           
@@ -133,7 +124,7 @@ namespace test{
           
           std::sort (content.children.begin(), content.children.end());
           
-          ++content;
+          ++content; // now leaving attributes and entering child scope...
           CHECK (!content.currIsAttrib());
           CHECK (content.currIsChild());
           CHECK ("γ" == *content.pos);
@@ -151,6 +142,8 @@ namespace test{
           VERIFY_ERROR (ITER_EXHAUST, ++content);
           
           content.resetPos();
+          CHECK (content.currIsAttrib());
+          CHECK (!content.currIsChild());
           CHECK (rawElm == & *content.pos);
           ++content;
           CHECK ("b = β" == *content.pos);
@@ -163,7 +156,7 @@ namespace test{
           
           mut.replace(subject);
           CHECK (Seq({"a = α", "b = β", "γ", "δ", "ε"}) == contents(subject));
-          std::cout << string(subject) << std::endl;
+          CHECK ("Rec(🌰| a = α, b = β |{γ, δ, ε})" == string(subject));
         }
     };