[r123.2] Is By Wall miss detection

Link to .capx file (required!):

https://dl.dropbox.com/u/39382262/BUG/ByWall/ByWallBug.capx

<img src="http://i49.tinypic.com/othifo.png" border="0">

Steps to reproduce:

1. Walk to the edge, under the YELLOW brick (either left / right side)

2. Press UP first to jump, then press LEFT / RIGHT when you're right in front of the YELLOW brick

3. Sometimes HAS / BY WALL will miss detection

4. Also try moving backward 1 grid, then press UP+LEFT / UP+RIGHT at the same time

<img src="http://i46.tinypic.com/30de0kl.png" border="0">

Observed result:

Sometimes HAS / BY WALL condition will miss detection

Expected result:

HAS / BY WALL always detected correctly

Browsers affected:

Chrome: yes

Firefox: n/a

Internet Explorer: n/a

Operating system & service pack:

Windows 7 x64

Construct 2 version:

123.2

Closing as won't fix: the problem is the "is by wall" check moves the object up (so it doesn't register an overlap with the floor or slope), then across. If when it first moves the object up it finds it's overlapping something, it determines it must be the ceiling, and gives up on detecting a wall and returns false. This means 'Is by wall' doesn't work if the player's head is right by the ceiling. I can't really change this, because if it moves the player only horizontally to test wall collisions, then slopes also trigger 'Is by wall' which is clearly wrong. I'm afraid I think you'll just have to find a way to work around this with detector sprites or 'Overlapping at offset'.