Created attachment 112142 [details]
Demonstration of 45 degree lines
Steps to reproduce:
1. Use "Pixel Brush" and the Line Tool.
2. Click and hold. Then hold shift and drag out a 45 degree angle.
The resulting line tends to have random jaggies along the line. (See the attached example.) On rare occasions the line is perfect, though I haven't been able to nail down exactly what triggers this.
Neat corner-to-corner pixels making up a line.
*** This bug has been marked as a duplicate of bug 387242 ***