fix apt scrollbars

buffer/buffer.go

@@ -638,6 +638,17 @@ func (buffer *Buffer) Backspace() {
 
 func (buffer *Buffer) CarriageReturn() {
 	defer buffer.emitDisplayChange()
+	for {
+		line := buffer.getCurrentLine()
+		if line == nil {
+			break
+		}
+		if line.wrapped && buffer.cursorY > 0 {
+			buffer.cursorY--
+		} else {
+			break
+		}
+	}
 	buffer.cursorX = 0
 }
 

buffer/buffer_test.go

@@ -223,11 +223,39 @@ func TestClearWithFullView(t *testing.T) {
 
 func TestCarriageReturn(t *testing.T) {
 	b := NewBuffer(80, 20, CellAttributes{})
-	b.Write([]rune("hello!\rsecret")...)
+	b.Write([]rune("hello!")...)
+	b.CarriageReturn()
+	b.Write([]rune("secret")...)
 	lines := b.GetVisibleLines()
 	assert.Equal(t, "secret", lines[0].String())
 }
 
+func TestCarriageReturnOnFullLine(t *testing.T) {
+	b := NewBuffer(20, 20, CellAttributes{})
+	b.Write([]rune("abcdeabcdeabcdeabcde")...)
+	b.CarriageReturn()
+	b.Write([]rune("xxxxxxxxxxxxxxxxxxxx")...)
+	lines := b.GetVisibleLines()
+	assert.Equal(t, "xxxxxxxxxxxxxxxxxxxx", lines[0].String())
+}
+
+func TestCarriageReturnOnOverflowedLine(t *testing.T) {
+	b := NewBuffer(20, 20, CellAttributes{})
+	b.Write([]rune("abcdeabcdeabcdeabcdezzzzz")...)
+	b.CarriageReturn()
+	b.Write([]rune("xxxxxxxxxxxxxxxxxxxx")...)
+	lines := b.GetVisibleLines()
+	assert.Equal(t, "xxxxxxxxxxxxxxxxxxxx", lines[0].String())
+}
+
+func TestCarriageReturnOnFullLastLine(t *testing.T) {
+	b := NewBuffer(20, 2, CellAttributes{})
+	b.Write([]rune("\nabcdeabcdeabcdeabcde\rxxxxxxxxxxxxxxxxxxxx")...)
+	lines := b.GetVisibleLines()
+	assert.Equal(t, "", lines[0].String())
+	assert.Equal(t, "xxxxxxxxxxxxxxxxxxxx", lines[1].String())
+}
+
 func TestCarriageReturnOnWrappedLine(t *testing.T) {
 	b := NewBuffer(80, 6, CellAttributes{})
 	b.Write([]rune("hello!\rsecret")...)
@@ -253,11 +281,10 @@ func TestCarriageReturnOnOverWrappedLine(t *testing.T) {
 	b := NewBuffer(6, 10, CellAttributes{})
 	b.Write([]rune("hello there!\rsecret sauce")...)
 	lines := b.GetVisibleLines()
-	require.Equal(t, 3, len(lines))
+	require.Equal(t, 2, len(lines))
-	assert.Equal(t, "hello", lines[0].String())
+	assert.Equal(t, "secret", lines[0].String())
-	assert.Equal(t, "secret", lines[1].String())
 	assert.True(t, b.lines[1].wrapped)
-	assert.Equal(t, " sauce", lines[2].String())
+	assert.Equal(t, " sauce", lines[1].String())
 }
 
 func TestCarriageReturnOnLineThatDoesntExist(t *testing.T) {