ln() does nothing at the beginning of a new file

[gmischler]

Error details
ln() moves self.y either by its "h" argument or by self._lasth.
At the beginning of a file, _lasth is 0, so

Minimal code

from fpdf import FPDF
pdf = FPDF()
print(pdf.y)
pdf.ln()
print(pdf.y)

Expected result:

10
14.23333

Actual result:

10
10

Since we have a default font size of 12 points, I would expect self.y to get moved by that much in this situation.
I tried to fix that in #897, but then noticed that quite a few of our tests start with an ineffective ln() (usually within a loop where it later does have an effect). I didn't want to change all those otherwise unrelated tests (under shapes), so I'm bringing it up here.

The fix would be to simply use self.font_size if the other two values (the parameter "h" or self._lasth) are None and 0.

[Lucas-C]

The fix would be to simply use self.font_size if the other two values (the parameter "h" or self._lasth) are None and 0.

I agree that this should be fixed.

However wouldn't it be better to simply initialize self._lasth to self.font_size?

[gmischler]

However wouldn't it be better to simply initialize self._lasth to self.font_size?

pdf = FPDF()
pdf.set_font("helvetica", size=36)
pdf.ln()

By how much would pdf.y move down in that case?
I think we really need to use the current value of pdf.font_size.

[Lucas-C]

I think we really need to use the current value of pdf.font_size.

Alright!

And let's use your sample in a unit test 🙂