Half of word-spacing to a space at the end of a TextBox

[bot-jonas]

Hello, I get different results from Chrome and Weasyprint when trying to use word-spacing in text that ends with a space. Weasyprint only adds half of word-spacing to these cases.

The following code illustrates the problem.

<style type="text/css">
	@page { size: 200px; margin: 0 }
	body { margin: 0; font: 15pt monospace }
	.ws { word-spacing: 50px }
	.ws2 { word-spacing: 100px }
</style>
<div class="ws">a b</div>
<div class="ws">c <b></b>d</div>
<div class="ws2">e <b></b>f</div>

WeasyPrint:

Chrome:

I found a reference to this problem in this TODO:

WeasyPrint/tests/test_text.py

Lines 473 to 474 in 4377c38

	# TODO: Pango gives only half of word-spacing to a space at the end
	# of a TextBox. Is this what we want?

Currently, I am fixing this problem changing this code

WeasyPrint/weasyprint/text/line_break.py

Lines 184 to 190 in 4377c38

	if word_spacing:
	space_spacing = (
	units_from_double(word_spacing) + letter_spacing)
	position = bytestring.find(b' ')
	while position != -1:
	add_attr(position, position + 1, space_spacing)
	position = bytestring.find(b' ', position + 1)

to this

if word_spacing:
    space_spacing = (
        units_from_double(word_spacing) + letter_spacing)
    position = bytestring.find(b' ')
    last_position = len(bytestring) - 1
    while position != -1:
        factor = 1 + (position == last_position)
        add_attr(position, position + 1, factor * space_spacing)
        position = bytestring.find(b' ', position + 1)

[liZe]

Thanks a lot for your report!

You fix works for spaces at the end, that’s cool. We have the same problem at the beginning, but that’s a detail.

Would you like to open a PR? I’ll add the second part of the fix and some tests.

[bot-jonas]

I opened a PR.

There is also the case with only one space:

<div class="ws">g<b> </b>f</div>

[liZe]

There is also the case with only one space

😱

Setting Pango’s letter spacing doesn’t work in this case because there’s only one letter. I’ll have to find one more workaround…