fitBounds with custom projection acts really strange

At first I thought that this is fixed with this really easy fix https://github.com/Leaflet/Leaflet/issues/4528, but looks like it actually is not, and by doing the fix a new possible issue has occurred, not 100% sure. Also looks like the fix was actually not done in the right place, probably. This is all speculation, because I cannot reproduce the issue using plain Leaflet, but with a custom projection this issue pops up and does not go away.

By removing the .add(padding) from the boundsSize we now can ran into issues when working with bounds that are just a point and in that case boundsSize will be 0 and will cause trouble on this line calculating scale as Infinity and because of that getBoundsZoom returns NaN: var scale = Math.min(size.x / boundsSize.x, size.y / boundsSize.y);

Working beta2: http://playground-leaflet.rhcloud.com/divo/1/edit?html,output Working 0.7.7: http://playground-leaflet.rhcloud.com/nov/1/edit?html,output Not working master: http://playground-leaflet.rhcloud.com/gin/1/edit?html,output Not working rc1: http://playground-leaflet.rhcloud.com/cit/1/edit?html,output

The other issue I have is that in getBoundsZoom function we have this line: zoom = this.getScaleZoom(scale, zoom);

Since zoom is set before like this var zoom = this.getZoom() || 0 when we call getScaleZoom it always gives different result when we pass the function different zoom level and the same scale. If we do multiple fitBounds() calls in a row with the same bounds, but different starting zoom level (do one call, then do another from the resulting zoom level, then do another) this causes map to zoom around strangely. Size and boundsSize does not change, but the calculated zoom using getScaleZoom changes due to the changes in the starting zoom level.

Issue shown on rc1: http://playground-leaflet.rhcloud.com/faf/1/edit?html,output Working as expected on beta2: http://playground-leaflet.rhcloud.com/gug/1/edit?html,output Not working at all on master: http://playground-leaflet.rhcloud.com/quxi/1/edit?html,output – Click on the fitBounds button under the map to see the issue in action

Looks like this is the commit that kind of turned things ugly using custom projections https://github.com/Leaflet/Leaflet/commit/3fde3c0390e03c6d0187ede1c9418c3c57fd1765

So probably I should ask @IvanSanchez to take a look at this

[theashyster]

I have retested the original issue after the pull requests has been merged, it seems to be gone now. So closing the issue.

[theashyster]

Hi, all, I have created two pull requests to fix this issue using the steps provided by @IvanSanchez Take a look when you have the time 😃