Fix rendering of the prompt line when overflow occurs with --info=inline

Fix #2692

src/util/util_test.go

@@ -38,3 +38,19 @@ func TestOnce(t *testing.T) {
 		t.Error("Expected: false")
 	}
 }
+
+func TestRunesWidth(t *testing.T) {
+	for _, args := range [][]int{
+		{100, 5, -1},
+		{3, 4, 3},
+		{0, 1, 0},
+	} {
+		width, overflowIdx := RunesWidth([]rune("hello"), 0, 0, args[0])
+		if width != args[1] {
+			t.Errorf("Expected width: %d, actual: %d", args[1], width)
+		}
+		if overflowIdx != args[2] {
+			t.Errorf("Expected overflow index: %d, actual: %d", args[2], overflowIdx)
+		}
+	}
+}