Only append a state if the value differs from the last current value.

2 files changed, 10 insertions, 1 deletions

diff --git a/lexlib/SparseState.h b/lexlib/SparseState.h
index 39b6e605a..953800a44 100644
--- a/lexlib/SparseState.h
+++ b/lexlib/SparseState.h
@@ -30,7 +30,9 @@ class SparseState {
 public:
 	void Set(int position, T value) {
 		Delete(position);
-		states.push_back(State(position, value));
+		if ((states.size() == 0) || (value != states[states.size()-1].value)) {
+			states.push_back(State(position, value));
+		}
 	}
 	T ValueAt(int position) {
 		if (!states.size())
diff --git a/test/unit/testSparseState.cxx b/test/unit/testSparseState.cxx
index f16f829d4..74f1032b2 100644
--- a/test/unit/testSparseState.cxx
+++ b/test/unit/testSparseState.cxx
@@ -95,6 +95,13 @@ TEST_F(SparseStateTest, ReplaceLast) {
 	EXPECT_EQ(32, pss->ValueAt(3));
 }
 
+TEST_F(SparseStateTest, CheckOnlyChangeAppended) {
+	pss->Set(0, 30);
+	pss->Set(2, 31);
+	pss->Set(3, 31);
+	EXPECT_EQ(2u, pss->size());
+}
+
 class SparseStateStringTest : public ::testing::Test {
 protected:
 	virtual void SetUp() {