Fix justify non breaking spaces

tests/draw/test_text.py

@@ -453,6 +453,59 @@ def test_text_align_justify(assert_pixels):
       <div>a c e</div>''')
 
 
+def test_text_align_justify_nbsp(assert_pixels):
+    assert_pixels('''
+        _________
+        _RR___RR_
+        _RR___RR_
+        _RR______
+        _RR______
+        _________
+    ''', '''
+      <style>
+        @page {
+          size: 9px 6px;
+        }
+        body {
+          color: red;
+          font-family: weasyprint;
+          font-size: 2px;
+        }
+        div {
+          line-height: 1;
+          margin: 1px;
+          text-align: justify;
+        }
+      </style>
+      <div>a&nbsp;c e</div>''')
+
+def test_text_align_justify_nbsp_2(assert_pixels):
+    assert_pixels('''
+        _________
+        _RR_RR_RR
+        _RR_RR_RR
+        _________
+        _________
+        _________
+    ''', '''
+      <style>
+        @page {
+          size: 9px 6px;
+        }
+        body {
+          color: red;
+          font-family: weasyprint;
+          font-size: 2px;
+        }
+        div {
+          line-height: 1;
+          margin: 1px;
+          text-align: justify;
+        }
+      </style>
+      <div>a\u202Fc\u202Fe</div>''')
+
+
 def test_text_word_spacing(assert_pixels):
     assert_pixels('''
         ___________________

weasyprint/layout/inline.py

@@ -1128,7 +1128,8 @@ def justify_line(context, line, extra_width):
 def count_spaces(box):
     if isinstance(box, boxes.TextBox):
         # TODO: remove trailing spaces correctly
-        return box.text.count(' ')
+        # here we count spaces and non-breaking spaces
+        return box.text.count(' ') + box.text.count("\u00A0")
     elif isinstance(box, (boxes.LineBox, boxes.InlineBox)):
         return sum(count_spaces(child) for child in box.children)
     else:

weasyprint/text/line_break.py

@@ -186,14 +186,31 @@ def add_attr(start, end, spacing):
                     text, bytestring = unicode_to_char_p(self.text)
                     pango.pango_layout_set_text(self.layout, text, -1)
 
+                nbsp = b'\xC2\xA0' # somehow \u00A0 is converted into this
                 space_spacing = int(word_spacing * TO_UNITS + letter_spacing)
-                position = bytestring.find(b' ')
+
+                def find_next_pos(start=0):
+                    """
+                    search for first occurrence of ' ' or NBSP
+                    return index (or -1) and lenght of searched string
+                    """
+                    p1 = bytestring.find(b' ', start)
+                    p2 = bytestring.find(nbsp, start)
+                    if p1 == -1 and p2 == -1:
+                        return -1, None
+                    if p2 == -1:
+                        return p1, 1
+                    if p1 == -1 or p2 < p1:
+                        return p2, 2
+                    return p1, 1
+
+                position, splen = find_next_pos()
                 # Pango gives only half of word-spacing on boundaries
                 boundary_positions = (0, len(bytestring) - 1)
                 while position != -1:
                     factor = 1 + (position in boundary_positions)
-                    add_attr(position, position + 1, factor * space_spacing)
-                    position = bytestring.find(b' ', position + 1)
+                    add_attr(position, position + splen, factor * space_spacing)
+                    position, splen = find_next_pos(position + splen)
 
             if word_breaking:
                 attr = pango.pango_attr_insert_hyphens_new(False)