Scatter Plots over Contour add unwanted padding

[daixtrose]

See https://codepen.io/daixtrose-1471261562/pen/dpGBQO

I draw a countour and 2 scatter lines in the same plot. Without the scatter lines the countour plot fully fills the 1000px times 1000px area as expected after setting

var layout = {
    autosize: false,
    autoexpand: true,
    width: 1000,
    height: 1000,
    margin: {
      l: 0,
      r: 0,
      b: 0,
      t: 0,
      pad: 0
    }, /* ... */

Now when I add 2 scatter lines it looks like place above the plot is reserved for the legend even if showlegend: false is set for both of them:

[daixtrose]

Full source:

var data = [{
  x: [0, 1000,   2000,   3000,   4000,   5000,   6000,   6500],
  y: [0, 5,  10, 15, 20, 25, 30],
  z: [
    [ 0.00, 0.00,   0.00,   0.00,   0.00,   0.00,   0.00,   0.00     ],
[ 0.00, 0.00,   0.00,   0.00,   0.00,   0.00,   0.00,   0.00        ],
[ 0.00, 0.00,   0.00,   0.00,   0.00,   0.00,   0.00,   0.00        ],
[ 12.67,    12.67,  12.67,  24.74,  22.31,  10.77,  10.77,  10.77   ],
[ 20.23,    20.23,  20.23,  39.23,  34.31,  34.31,  34.31,  34.31   ],
[ 26.99,    26.99,  26.99,  52.22,  45.18,  45.18,  45.18,  45.18   ],
[ 30.00,    30.00,  30.00,  58.00,  50.00,  50.00,  50.00,  50.00   ]
  ],
  zmin: 0,
  zmax: 1,
  xmin: 0,
  type: 'contour',
  hoverinfo: "none",
  autocontour: false,
  contours: {
    start: 0,
    end: 60,
    size: 3,
    showlines: false
  },
  showscale: false,
  showlegend: false,
  zauto: false,
  colorscale: [
    [0, 'rgb(255, 255, 255)'],
    [1, 'rgb(8, 78, 170)']
  ]
}, {
  x: [ 0, 800, 1000, 1250, 1500, 1750, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500 ],
  y: [ 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30 ],
  type: 'scatter',
  marker: {
    size: 1
  },
  line: {
    color: 'transparent'
  },
  showlegend: false
}, 
            {
  x: [ 0, 800, 1000, 1250, 1500, 1750, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500 ],
  y: [ 0, 17, 19, 23, 25, 26, 27, 28, 30, 30, 29, 27, 25, 22, 21, 17 ],
  type: 'scatter', 
  fill: 'tonexty',
  marker: {
    size: 1
  }, 
  fillcolor: 'white',
  line: {
    color: '#da1f3d'
  },
  showlegend: false
}];

var layout = {
    autosize: false,
    autoexpand: true,
    width: 1000,
    height: 1000,
    margin: {
      l: 0,
      r: 0,
      b: 0,
      t: 0,
      pad: 0
    },
    xaxis: {
    autorange: true,
    showgrid: false,
    zeroline: false,
    showline: false,
    autotick: true,
    ticks: '1',
    showticklabels: false
  },
  yaxis: {
    autorange: true,
    showgrid: false,
    zeroline: false,
    showline: false,
    autotick: true,
    ticks: '',
    showticklabels: false
  }
}

Plotly.newPlot('myDiv', data, layout);

[etpinard]

That's the desired behaviour under xaxis.autorange / yaxis.autorange true - where the scatter traces present expand the axis with a little more padding than the contour trace by design.

We might want to look at #928 for more info.

In the meantime, setting xaxis.range and yaxis.range to fix values should give you the desired results: https://codepen.io/etpinard/pen/ozxjBg