[BUG] Fill didn't start from zeroLine in mixed lines/bar chart

Expected Behavior

There are two lines and a bar in a mixed type chart, I want to fill space between these two lines,

new Chart(ctx, {
    type: 'bar',
    data: {
        datasets: [
            {...} ,           // this is a bar
            {fill: '+1'},      // this is a line
            {fill: false},      // this is another line
        ]
    }
})

but I found the fill didn’t start from index zero,

But in a lines only chart, the fill worked as expected, starting from index 0. Just removed bar from above demo

Current Behavior

Possible Solution

Steps to Reproduce (for bugs)

Context

Environment

• Chart.js version: 2.6
• Browser name and version: Ionic (WebView)
• Link to your project:

[nagix]

I think this is not a bug, and the behavior of a line-only chart has changed by #4545 so that a line starts from the midpoint of grid lines with or without bars. There are no options to simply extend these lines.

As a workaround, you can add extra columns at the beginning and end, and use ticks.min and ticks.max options. By the way, 2.6 has an issue about fill area clipping (#4450), so you need the version from the latest master.

See https://jsfiddle.net/zkr59bfx/

[nagix]

@qiluo This seems a bug in the filler plugin. I opend #4696.