Ace Editor Bug: Markers on long lines "drift" to the right

[jvilk]

BLeak's viewer uses the Ace Editor to display source code, and uses Ace Editor's markers to highlight source locations that contribute to memory leaks. These markers drift to the right on long lines, causing the highlight to fall on incorrect characters.

I have triple checked the markers that BLeak is issuing to the Ace Editor, as well as the offset in the line, and have verified that this is an issue in the Ace Editor. The source lines contain no funky unicode characters, so number of characters making up the offset is equal to the byte length of the line expressed as UTF8.

The Ace Editor calculates the pixel location of a marker by multiplying the width of a monospace font character with the offset. It seems like there is some error accumulating over each character, causing the markers to drift on long offsets.