duplicate trace on replot

[wave-electron]

I've discovered a very annoying bug that duplicates the traces on the 2nd replot. It doesn't happen on the cran version only on dev.

With cran version you get the correct number of traces on replot.

This duplication occurs in the dev version

Here is the code snippet in Shiny I was using to reproduce the bug

server = function(input, output)  {
   
        # original plot
       output$plot1 <- renderPlotly({
                p <- plot_ly(type = "scatter") %>%
                        add_trace(p,x =c( 1, 2, 3 ),y =c(5, 6,7),mode = "lines", color="Original Trace 1") %>%
                        add_trace(p,x =c( 2, 3, 4 ),y =c(7, 8,9),mode = "lines",color = "Original Trace2") %>% 
                        layout(title = "original Plot",showlegend = TRUE)   
        })
        
        # create new plot
        observeEvent(input$newplot,{
         
                                output$plot1 <- renderPlotly({
                                    p <-  plot_ly(type="scatter") %>%
                                                add_trace(p, x =c(1,2,3 ),y =c(5,6,7),mode = "lines",color = "New Trace1") %>%
                                                add_trace(p,x =c( 2,3,4),y =c(7,8,9),mode = "lines",color = "New Trace2") %>% 
                                                layout(title = "New Plot",showlegend = TRUE) 
                                })
        }) 
        
        # clearplot
        observeEvent(input$clearplot,{
 
                                output$plot1 <- renderPlotly({
                                        plotly_empty()
                                })
        })
        
  
           
  }
               
                     

ui <- pageWithSidebar(
        
        headerPanel("Plotly version 4.5.6.9000 - bug (duplicate traces on replot)"),
        
        sidebarPanel(
                actionButton("newplot", "New plot"),
                actionButton("clearplot", "Clear plot")
        ),
        
        mainPanel(
                plotlyOutput("plot1", height = 500, width = 500)
        )
)
shinyApp(ui, server)

[fabiangehring]

+1 same issue with barplot

[wave-electron]

The duplication problem is reproducible on at least candle, area, bar, line, box, scatter ... i suspect it happens regardless of chart type.