While working on implementing the anchor parameter of ImageDraw.text (see #4511 (comment)), I noticed a bug with the handling of y_offset with raqm.

For the following code:

from PIL import Image, ImageDraw, ImageFont
font = ImageFont.truetype("segoeui.ttf", 60, layout_engine=ImageFont.LAYOUT_RAQM)
def test(text):
    im = Image.new("RGB", (200,200), "white")
    d = ImageDraw.Draw(im)
    d.line(((0,100),(200,100)), "black")
    d.line(((100,0),(100,200)), "black")
    d.text((100,100),text,"black", font=font)
    im.show()
test("a" + ("\u030C" * 20))    # a + 20 * Unicode Character 'COMBINING CARON' (U+030C)

I expect to get the following image:

But I get the following image (with master):

This is because when raqm support was added, the yoffset variable was not updated to look at the glyphinfo[i].y_offset value:

Since font_render looks at the bitmap.top value anyway (see below), which should be equal to bbox.yMax, I believe yoffset is supposed to calculate the same value as y_max, so it can just be removed and y_max used instead (in second snippet below).

I am planning to include this change in the PR implementing the anchor parameter, but I wanted to document this as a separate issue.