2 files changed, 71 insertions, 6 deletions

diff --git a/xdelta3/testing/modify.h b/xdelta3/testing/modify.h
index 8da03a2..2080904 100644
--- a/xdelta3/testing/modify.h
+++ b/xdelta3/testing/modify.h
@@ -111,7 +111,7 @@ void ChangeListMutator::Mutate(const Change &ch,
                                MTRandom *rand) {
   switch (ch.kind) {
   case Change::ADD:
-    //AddChange(ch, table, source_table, rand);
+    AddChange(ch, table, source_table, rand);
     break;
   case Change::MODIFY:
     ModifyChange(ch, table, source_table, rand);
@@ -164,6 +164,45 @@ void ChangeListMutator::ModifyChange(const Change &ch,
   }
 }
 
+void ChangeListMutator::AddChange(const Change &ch, 
+                                  SegmentMap *table,
+                                  const SegmentMap *source_table,
+                                  MTRandom *rand) {
+  xoff_t m_start = ch.addr1;
+
+  for (SegmentMap::const_iterator iter(source_table->begin()); 
+       iter != source_table->end();
+       ++iter) {
+    const Segment &seg = iter->second;
+    xoff_t i_start = iter->first;
+    xoff_t i_end = i_start + seg.length;
+
+    if (i_end <= m_start) {
+      table->insert(table->end(), make_pair(i_start, seg));
+      continue;
+    }
+
+    if (i_start > m_start) {
+      table->insert(table->end(), make_pair(i_start + ch.size, seg));
+      continue;
+    }
+
+    if (i_start < m_start) {
+      Segment before(seg.seed, m_start - i_start, seg.seed_offset);
+      table->insert(table->end(), make_pair(i_start, before));
+    }
+
+    Segment addseg(rand->Rand32(), ch.size);
+    table->insert(table->end(), make_pair(m_start, addseg));
+
+    if (m_start < i_end) {
+      Segment after(seg.seed, i_end - m_start, 
+                    seg.seed_offset + (m_start - i_start));
+      table->insert(table->end(), make_pair(m_start + ch.size, after));
+    }
+  }
+}
+
 class Modify1stByte : public Mutator {
 public:
   void Mutate(SegmentMap *table, 
@@ -172,9 +211,6 @@ public:
     ChangeListMutator::Mutate(Change(Change::MODIFY, 1, 0),
                               table, source_table, rand);
   }
-
-private:
-  ChangeListMutator clm_;
 };
 
 }  // namespace regtest
diff --git a/xdelta3/testing/regtest.cc b/xdelta3/testing/regtest.cc
index 12499ba..487a407 100644
--- a/xdelta3/testing/regtest.cc
+++ b/xdelta3/testing/regtest.cc
@@ -268,9 +268,7 @@ void TestModifyMutator() {
   for (size_t i = 0; i < SIZEOF_ARRAY(test_cases); i++) {
     ChangeList cl1;
     cl1.push_back(Change(Change::MODIFY, test_cases[i].size, test_cases[i].addr));
-    spec0.Print();
     spec0.ModifyTo(ChangeListMutator(cl1), &spec1);
-    spec1.Print();
     
     size_t diff = CmpDifferentBytes(spec0, spec1);
     CHECK_LE(diff, test_cases[i].size);
@@ -280,12 +278,43 @@ void TestModifyMutator() {
   }
 }
 
+void TestAddMutator() {
+  MTRandom rand;
+  FileSpec spec0(&rand);
+  FileSpec spec1(&rand);
+
+  spec0.GenerateFixedSize(Constants::BLOCK_SIZE * 2);
+
+  struct {
+    size_t size;
+    size_t addr;
+  } test_cases[] = {
+    { 1, 0 },
+    { 1, 1 },
+    { 1, Constants::BLOCK_SIZE - 1 },
+    { 1, Constants::BLOCK_SIZE },
+    { 1, Constants::BLOCK_SIZE + 1},
+    { 1, 2 * Constants::BLOCK_SIZE },
+  };
+
+  for (size_t i = 0; i < SIZEOF_ARRAY(test_cases); i++) {
+    ChangeList cl1;
+    cl1.push_back(Change(Change::ADD, test_cases[i].size, test_cases[i].addr));
+    spec0.Print();
+    spec0.ModifyTo(ChangeListMutator(cl1), &spec1);
+    spec1.Print();
+    
+    InMemoryEncodeDecode(spec0, spec1);
+  }
+}
+
 int main(int argc, char **argv) {
 #define TEST(x) cerr << #x << "..." << endl; x()
   TEST(TestRandomNumbers);
   TEST(TestRandomFile);
   TEST(TestFirstByte);
   TEST(TestModifyMutator);
+  TEST(TestAddMutator);
   return 0;
 }