Kozea · liZe · Jan 16, 2022 · Jan 5, 2022 · Jan 5, 2022
diff --git a/tests/test_text.py b/tests/test_text.py
@@ -921,6 +921,42 @@ def test_overflow_wrap(wrap, text, test, full_text):
     assert full_text == lines_full_text
 
 
+@assert_no_logs
+@pytest.mark.parametrize('span_css, expected_lines', (
+    # overflow-wrap: anywhere and break-word are only allowed to break a word
+    # "if there are no otherwise-acceptable break points in the line", which
+    # means they should not split a word if it fits cleanly into the next line.
+    # This can be done accidentally if it is in its own inline element.
+    ('overflow-wrap: anywhere', ['aaa', 'bbb']),
+    ('overflow-wrap: break-word', ['aaa', 'bbb']),
+
+    # On the other hand, word-break: break-all mandates a break anywhere at the
+    # end of a line, even if the word could fit cleanly onto the next line.
+    ('word-break: break-all', ['aaa b', 'bb']),
+))
+def test_wrap_overflow_word_break(span_css, expected_lines):
+    page, = render_pages('''
+      <style>
+        @font-face {src: url(weasyprint.otf); font-family: weasyprint}
+        body {width: 80px; overflow: hidden; font-family: weasyprint}
+        span {%s}
+      </style>
+      <body>
+        <span>aaa </span><span>bbb
+    ''' % span_css)
+    html, = page.children
+    body, = html.children
+    lines = body.children
+    lines = []
+    print(body.children)
+    for line in body.children:
+        line_text = ''
+        for span_box in line.children:
+            line_text += span_box.children[0].text
+        lines.append(line_text)
+    assert lines == expected_lines
+
+
 @assert_no_logs
 @pytest.mark.parametrize('wrap, text, body_width, expected_width', (
     ('anywhere', 'aaaaaa', 10, 20),

diff --git a/weasyprint/css/properties.py b/weasyprint/css/properties.py
@@ -154,6 +154,7 @@
     'text_indent': Dimension(0, 'px'),
     'text_transform': 'none',
     'white_space': 'normal',
+    'word_break': 'normal',
     'word_spacing': 0,  # computed value for 'normal'
 
     # Transforms 1 (CR): https://www.w3.org/TR/css-transforms-1/
@@ -270,6 +271,7 @@
     'visibility',
     'white_space',
     'widows',
+    'word_break',
     'word_spacing',
 }
 

diff --git a/weasyprint/css/validation/properties.py b/weasyprint/css/validation/properties.py
@@ -1179,6 +1179,13 @@ def overflow_wrap(keyword):
     return keyword in ('anywhere', 'normal', 'break-word')
 
 
+@property()
+@single_keyword
+def word_break(keyword):
+    """``word-break`` property validation."""
+    return keyword in ('normal', 'break-all')
+
+
 @property()
 @single_token
 def flex_basis(token):

diff --git a/weasyprint/layout/inline.py b/weasyprint/layout/inline.py
@@ -472,8 +472,10 @@ def split_inline_level(context, box, position_x, max_x, bottom_space,
             skip = skip or 0
             assert skip_stack is None
 
+        is_line_start = len(line_children) == 0
         new_box, skip, preserved_line_break = split_text_box(
-            context, box, max_x - position_x, skip)
+            context, box, max_x - position_x, skip,
+            is_line_start=is_line_start)
 
         if skip is None:
             resume_at = None
@@ -882,7 +884,7 @@ def split_inline_box(context, box, position_x, max_x, bottom_space, skip_stack,
         float_widths)
 
 
-def split_text_box(context, box, available_width, skip):
+def split_text_box(context, box, available_width, skip, is_line_start=True):
     """Keep as much text as possible from a TextBox in a limited width.
 
     Try not to overflow but always have some text in ``new_box``.
@@ -900,7 +902,8 @@ def split_text_box(context, box, available_width, skip):
     if font_size == 0 or not text:
         return None, None, False
     layout, length, resume_index, width, height, baseline = split_first_line(
-        text, box.style, context, available_width, box.justification_spacing)
+        text, box.style, context, available_width, box.justification_spacing,
+        is_line_start=is_line_start)
     assert resume_index != 0
 
     # Convert ``length`` and ``resume_at`` from UTF-8 indexes in text

diff --git a/weasyprint/layout/preferred.py b/weasyprint/layout/preferred.py
@@ -307,7 +307,7 @@ def inline_line_widths(context, box, outer, is_line_start, minimum,
                         split_first_line(
                             child_text[resume_index:], child.style, context,
                             max_width, child.justification_spacing,
-                            minimum=True))
+                            is_line_start=is_line_start, minimum=True))
                     lines.append(width)
                     if first_line:
                         break

diff --git a/weasyprint/text/line_break.py b/weasyprint/text/line_break.py
@@ -302,7 +302,7 @@ def create_layout(text, style, context, max_width, justification_spacing):
 
 
 def split_first_line(text, style, context, max_width, justification_spacing,
-                     minimum=False):
+                     is_line_start=True, minimum=False):
     """Fit as much as possible in the available width for one line of text.
 
     Return ``(layout, length, resume_index, width, height, baseline)``.
@@ -545,8 +545,12 @@ def split_first_line(text, style, context, max_width, justification_spacing,
     first_line_width, _ = line_size(first_line, style)
     space = max_width - first_line_width
     # If we can break words and the first line is too long
-    if space < 0 and (overflow_wrap == 'anywhere' or
-                      (overflow_wrap == 'break-word' and not minimum)):
+    if space < 0 and ((style['word_break'] == 'break-all') or
+                      (is_line_start and
+                       (
+                        overflow_wrap == 'anywhere' or
+                        (overflow_wrap == 'break-word' and not minimum)
+                       ))):
         # Is it really OK to remove hyphenation for word-break ?
         hyphenated = False
         # TODO: Modify code to preserve W3C condition: