tile: avoid rendering beyond document boundary

problem:
i.e: if calc sheet has most of row hidden and remaining
rows don't cover the canvas area then
1. canvas center was incorrectly calculated based on
available area instead the required doc area
2. grids were drawn beyond the last visible raw

Signed-off-by: Pranam Lashkari <lpranam@collabora.com>
Change-Id: I1f43e37e104c693b8f070271dac620385c0a2dd0

browser/src/layer/tile/CanvasTileLayer.js

@@ -4154,8 +4154,8 @@ L.CanvasTileLayer = L.Layer.extend({
 			var mapElement = document.getElementById('map'); // map's size = tiles section's size.
 			mapElement.style.left = rectangle.getPxX1() + 'px';
 			mapElement.style.top = rectangle.getPxY1() + 'px';
-			mapElement.style.width = rectangle.getPxWidth() + 'px';
-			mapElement.style.height = rectangle.getPxHeight() + 'px';
+			mapElement.style.width = Math.min(rectangle.getPxWidth(), app.file.size.pixels[0]) + 'px';
+			mapElement.style.height = Math.min(rectangle.getPxHeight(), app.file.size.pixels[1]) + 'px';
 
 			tileContainer.style.width = rectangle.getPxWidth() + 'px';
 			tileContainer.style.height = rectangle.getPxHeight() + 'px';