wip

internal/app/cursorshift_test.go

@@ -111,3 +111,40 @@ func TestCursorShifterCUPNoClampWhenChildColsZero(t *testing.T) {
 		t.Fatalf("childCols=0 should disable col clamping: got %q", got)
 	}
 }
+
+// In longer claude sessions the cursor's internal row state could drift
+// past the viewport height. CUP / HVP / VPA without row clamping would
+// then land the host cursor on the status row or above the tab bar,
+// where the next printable wipes the chrome.
+func TestCursorShifterClampsCUPRowToMainBottom(t *testing.T) {
+	// rowOffset=2 (mainTop=3), childRows=36 → mainBottom=38.
+	cs := newCursorShifter(2, 36, 80)
+	got := cs.Shift([]byte("\x1b[40;5H"))
+	if string(got) != "\x1b[38;5H" {
+		t.Fatalf("CUP row 40 (post-shift 42) should clamp to 38: got %q", got)
+	}
+}
+
+func TestCursorShifterClampsHVPRowToMainBottom(t *testing.T) {
+	cs := newCursorShifter(2, 36, 80)
+	got := cs.Shift([]byte("\x1b[99;1f"))
+	if string(got) != "\x1b[38;1f" {
+		t.Fatalf("HVP row 99 should clamp to mainBottom: got %q", got)
+	}
+}
+
+func TestCursorShifterClampsVPARow(t *testing.T) {
+	cs := newCursorShifter(2, 36, 80)
+	got := cs.Shift([]byte("\x1b[60d"))
+	if string(got) != "\x1b[38d" {
+		t.Fatalf("VPA row 60 should clamp to mainBottom: got %q", got)
+	}
+}
+
+func TestCursorShifterCUPRowNoClampWhenChildRowsZero(t *testing.T) {
+	cs := newCursorShifter(2, 0, 80)
+	got := cs.Shift([]byte("\x1b[40;5H"))
+	if string(got) != "\x1b[42;5H" {
+		t.Fatalf("childRows=0 should disable row clamping: got %q", got)
+	}
+}