diff --git a/components/gfx/text/text_run.rs b/components/gfx/text/text_run.rs
index 21c239257fb00..a40d82387a99a 100644
--- a/components/gfx/text/text_run.rs
+++ b/components/gfx/text/text_run.rs
@@ -225,6 +225,16 @@ impl<'a> TextRun {
 
         let breaker = breaker.as_mut().unwrap();
 
+        let mut push_range = |range: &std::ops::Range<usize>, options: &ShapingOptions| {
+            glyphs.push(GlyphRun {
+                glyph_store: font.shape_text(&text[range.clone()], &options),
+                range: Range::new(
+                    ByteIndex(range.start as isize),
+                    ByteIndex(range.len() as isize),
+                ),
+            });
+        };
+
         while !finished {
             let (idx, _is_hard_break) = breaker.next(text);
             if idx == text.len() {
@@ -240,9 +250,9 @@ impl<'a> TextRun {
 
             // Split off any trailing whitespace into a separate glyph run.
             let mut whitespace = slice.end..slice.end;
-            if let Some((i, _)) = word
-                .char_indices()
-                .rev()
+            let mut rev_char_indices = word.char_indices().rev().peekable();
+            let ends_with_newline = rev_char_indices.peek().map_or(false, |&(_, c)| c == '\n');
+            if let Some((i, _)) = rev_char_indices
                 .take_while(|&(_, c)| char_is_whitespace(c))
                 .last()
             {
@@ -254,26 +264,28 @@ impl<'a> TextRun {
                 continue;
             }
             if !slice.is_empty() {
-                glyphs.push(GlyphRun {
-                    glyph_store: font.shape_text(&text[slice.clone()], options),
-                    range: Range::new(
-                        ByteIndex(slice.start as isize),
-                        ByteIndex(slice.len() as isize),
-                    ),
-                });
+                push_range(&slice, options);
             }
             if !whitespace.is_empty() {
                 let mut options = *options;
                 options
                     .flags
                     .insert(ShapingFlags::IS_WHITESPACE_SHAPING_FLAG);
-                glyphs.push(GlyphRun {
-                    glyph_store: font.shape_text(&text[whitespace.clone()], &options),
-                    range: Range::new(
-                        ByteIndex(whitespace.start as isize),
-                        ByteIndex(whitespace.len() as isize),
-                    ),
-                });
+
+                // The breaker breaks after every newline, so either there is none,
+                // or there is exactly one at the very end. In the latter case,
+                // split it into a different run. That's because shaping considers
+                // a newline to have the same advance as a space, but during layout
+                // we want to treat the newline as having no advance.
+                if ends_with_newline {
+                    whitespace.end -= 1;
+                    if !whitespace.is_empty() {
+                        push_range(&whitespace, &options);
+                    }
+                    whitespace.start = whitespace.end;
+                    whitespace.end += 1;
+                }
+                push_range(&whitespace, &options);
             }
             slice.start = whitespace.end;
         }
diff --git a/components/layout_2020/flow/inline.rs b/components/layout_2020/flow/inline.rs
index 11b8f4a5ce5db..adeacce6e2cc7 100644
--- a/components/layout_2020/flow/inline.rs
+++ b/components/layout_2020/flow/inline.rs
@@ -2248,8 +2248,8 @@ struct ContentSizesComputation<'a> {
     current_line: ContentSizes,
     /// Size for whitepsace pending to be added to this line.
     pending_whitespace: Au,
-    /// Whether or not this IFC has seen any non-whitespace content.
-    had_non_whitespace_content_yet: bool,
+    /// Whether or not this IFC has seen any content, excluding discarded whitespace.
+    had_content_yet: bool,
     /// Stack of ending padding, margin, and border to add to the length
     /// when an inline box finishes.
     ending_inline_pbm_stack: Vec<Length>,
@@ -2304,31 +2304,35 @@ impl<'a> ContentSizesComputation<'a> {
                     for run in segment.runs.iter() {
                         let advance = run.glyph_store.total_advance();
 
-                        if !run.glyph_store.is_whitespace() {
-                            self.had_non_whitespace_content_yet = true;
-                            self.current_line.min_content += advance;
-                            self.current_line.max_content += self.pending_whitespace + advance;
-                            self.pending_whitespace = Au::zero();
-                        } else {
+                        if run.glyph_store.is_whitespace() {
                             // If this run is a forced line break, we *must* break the line
                             // and start measuring from the inline origin once more.
-                            if text_run.glyph_run_is_whitespace_ending_with_preserved_newline(run) {
-                                self.had_non_whitespace_content_yet = true;
+                            if text_run.glyph_run_is_preserved_newline(run) {
+                                self.had_content_yet = true;
                                 self.forced_line_break();
                                 self.current_line = ContentSizes::zero();
                                 continue;
                             }
 
-                            // Discard any leading whitespace in the IFC. This will always be trimmed.
-                            if !self.had_non_whitespace_content_yet {
+                            let white_space =
+                                text_run.parent_style.get_inherited_text().white_space;
+                            // TODO: need to handle white_space.allow_wrap() too.
+                            if !white_space.preserve_spaces() {
+                                // Discard any leading whitespace in the IFC. This will always be trimmed.
+                                if self.had_content_yet {
+                                    // Wait to take into account other whitespace until we see more content.
+                                    // Whitespace at the end of the IFC will always be trimmed.
+                                    self.line_break_opportunity();
+                                    self.pending_whitespace += advance;
+                                }
                                 continue;
                             }
-
-                            // Wait to take into account other whitespace until we see more content.
-                            // Whitespace at the end of the IFC will always be trimmed.
-                            self.line_break_opportunity();
-                            self.pending_whitespace += advance;
                         }
+
+                        self.had_content_yet = true;
+                        self.current_line.min_content += advance;
+                        self.current_line.max_content += self.pending_whitespace + advance;
+                        self.pending_whitespace = Au::zero();
                     }
                 }
             },
@@ -2341,7 +2345,7 @@ impl<'a> ContentSizesComputation<'a> {
                 self.current_line.min_content += self.pending_whitespace + outer.min_content;
                 self.current_line.max_content += self.pending_whitespace + outer.max_content;
                 self.pending_whitespace = Au::zero();
-                self.had_non_whitespace_content_yet = true;
+                self.had_content_yet = true;
             },
             _ => {},
         });
@@ -2380,7 +2384,7 @@ impl<'a> ContentSizesComputation<'a> {
             paragraph: ContentSizes::zero(),
             current_line: ContentSizes::zero(),
             pending_whitespace: Au::zero(),
-            had_non_whitespace_content_yet: false,
+            had_content_yet: false,
             ending_inline_pbm_stack: Vec::new(),
         }
         .traverse(inline_formatting_context)
diff --git a/components/layout_2020/flow/text_run.rs b/components/layout_2020/flow/text_run.rs
index 2667c474d9ed0..d072124608c1b 100644
--- a/components/layout_2020/flow/text_run.rs
+++ b/components/layout_2020/flow/text_run.rs
@@ -150,7 +150,7 @@ impl TextRunSegment {
             // If this whitespace forces a line break, queue up a hard line break the next time we
             // see any content. We don't line break immediately, because we'd like to finish processing
             // any ongoing inline boxes before ending the line.
-            if text_run.glyph_run_is_whitespace_ending_with_preserved_newline(run) {
+            if text_run.glyph_run_is_preserved_newline(run) {
                 ifc.defer_forced_line_break();
                 continue;
             }
@@ -426,11 +426,8 @@ impl TextRun {
             self.prevent_soft_wrap_opportunity_at_end;
     }
 
-    pub(super) fn glyph_run_is_whitespace_ending_with_preserved_newline(
-        &self,
-        run: &GlyphRun,
-    ) -> bool {
-        if !run.glyph_store.is_whitespace() {
+    pub(super) fn glyph_run_is_preserved_newline(&self, run: &GlyphRun) -> bool {
+        if !run.glyph_store.is_whitespace() || run.range.length() != ByteIndex(1) {
             return false;
         }
         if !self
@@ -442,7 +439,7 @@ impl TextRun {
             return false;
         }
 
-        let last_byte = self.text.as_bytes().get(run.range.end().to_usize() - 1);
+        let last_byte = self.text.as_bytes().get(run.range.begin().to_usize());
         last_byte == Some(&b'\n')
     }
 }
diff --git a/tests/wpt/meta/css/CSS2/generated-content/content-175.xht.ini b/tests/wpt/meta/css/CSS2/generated-content/content-175.xht.ini
deleted file mode 100644
index 6d8d2bb07d3fb..0000000000000
--- a/tests/wpt/meta/css/CSS2/generated-content/content-175.xht.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[content-175.xht]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-009.xht.ini b/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-009.xht.ini
deleted file mode 100644
index 91d95f9df4755..0000000000000
--- a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-009.xht.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[table-anonymous-objects-009.xht]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-010.xht.ini b/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-010.xht.ini
deleted file mode 100644
index 12c3a9c74b3b3..0000000000000
--- a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-010.xht.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[table-anonymous-objects-010.xht]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-011.xht.ini b/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-011.xht.ini
deleted file mode 100644
index d230ae4bafbf1..0000000000000
--- a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-011.xht.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[table-anonymous-objects-011.xht]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-012.xht.ini b/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-012.xht.ini
deleted file mode 100644
index e08d936cda1f1..0000000000000
--- a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-012.xht.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[table-anonymous-objects-012.xht]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-197.xht.ini b/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-197.xht.ini
deleted file mode 100644
index fda41d32144e5..0000000000000
--- a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-197.xht.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[table-anonymous-objects-197.xht]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-198.xht.ini b/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-198.xht.ini
deleted file mode 100644
index 98c69fb5cd9fe..0000000000000
--- a/tests/wpt/meta/css/CSS2/tables/table-anonymous-objects-198.xht.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[table-anonymous-objects-198.xht]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/CSS2/text/white-space-pre-001.xht.ini b/tests/wpt/meta/css/CSS2/text/white-space-pre-001.xht.ini
deleted file mode 100644
index 8e2d4b13074ba..0000000000000
--- a/tests/wpt/meta/css/CSS2/text/white-space-pre-001.xht.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[white-space-pre-001.xht]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/css-lists/inline-list.html.ini b/tests/wpt/meta/css/css-lists/inline-list.html.ini
deleted file mode 100644
index ebcb4fec824f9..0000000000000
--- a/tests/wpt/meta/css/css-lists/inline-list.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[inline-list.html]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/tab-size/tab-size-integer-001.html.ini b/tests/wpt/meta/css/css-text/tab-size/tab-size-integer-001.html.ini
new file mode 100644
index 0000000000000..37c1a524220e8
--- /dev/null
+++ b/tests/wpt/meta/css/css-text/tab-size/tab-size-integer-001.html.ini
@@ -0,0 +1,2 @@
+[tab-size-integer-001.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/tab-size/tab-size-integer-002.html.ini b/tests/wpt/meta/css/css-text/tab-size/tab-size-integer-002.html.ini
new file mode 100644
index 0000000000000..066c0b60bdc76
--- /dev/null
+++ b/tests/wpt/meta/css/css-text/tab-size/tab-size-integer-002.html.ini
@@ -0,0 +1,2 @@
+[tab-size-integer-002.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/tab-size/tab-size-integer-003.html.ini b/tests/wpt/meta/css/css-text/tab-size/tab-size-integer-003.html.ini
new file mode 100644
index 0000000000000..0c6fd1eff9d98
--- /dev/null
+++ b/tests/wpt/meta/css/css-text/tab-size/tab-size-integer-003.html.ini
@@ -0,0 +1,2 @@
+[tab-size-integer-003.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/tab-size/tab-size-length-001.html.ini b/tests/wpt/meta/css/css-text/tab-size/tab-size-length-001.html.ini
new file mode 100644
index 0000000000000..81b7b1df8c751
--- /dev/null
+++ b/tests/wpt/meta/css/css-text/tab-size/tab-size-length-001.html.ini
@@ -0,0 +1,2 @@
+[tab-size-length-001.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/tab-size/tab-size-length-002.html.ini b/tests/wpt/meta/css/css-text/tab-size/tab-size-length-002.html.ini
new file mode 100644
index 0000000000000..86cf5cd341eae
--- /dev/null
+++ b/tests/wpt/meta/css/css-text/tab-size/tab-size-length-002.html.ini
@@ -0,0 +1,2 @@
+[tab-size-length-002.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/tab-size/tab-size-percent-001.html.ini b/tests/wpt/meta/css/css-text/tab-size/tab-size-percent-001.html.ini
new file mode 100644
index 0000000000000..5eb8b3b910198
--- /dev/null
+++ b/tests/wpt/meta/css/css-text/tab-size/tab-size-percent-001.html.ini
@@ -0,0 +1,2 @@
+[tab-size-percent-001.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-015.html.ini b/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-015.html.ini
deleted file mode 100644
index 89bdfca9200b5..0000000000000
--- a/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-015.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[white-space-intrinsic-size-015.html]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-016.html.ini b/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-016.html.ini
deleted file mode 100644
index cd83045f9ac8d..0000000000000
--- a/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-016.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[white-space-intrinsic-size-016.html]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-017.html.ini b/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-017.html.ini
deleted file mode 100644
index 1095373e38bcd..0000000000000
--- a/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-017.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[white-space-intrinsic-size-017.html]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-018.html.ini b/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-018.html.ini
deleted file mode 100644
index 368a69e07d33d..0000000000000
--- a/tests/wpt/meta/css/css-text/white-space/white-space-intrinsic-size-018.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[white-space-intrinsic-size-018.html]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/css-text/white-space/white-space-pre-wrap-trailing-spaces-002.html.ini b/tests/wpt/meta/css/css-text/white-space/white-space-pre-wrap-trailing-spaces-002.html.ini
deleted file mode 100644
index 6e57d825a394a..0000000000000
--- a/tests/wpt/meta/css/css-text/white-space/white-space-pre-wrap-trailing-spaces-002.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[white-space-pre-wrap-trailing-spaces-002.html]
-  expected: FAIL
diff --git a/tests/wpt/mozilla/meta/css/white-space-pre-wrap.htm.ini b/tests/wpt/mozilla/meta/css/white-space-pre-wrap.htm.ini
new file mode 100644
index 0000000000000..521c793832b93
--- /dev/null
+++ b/tests/wpt/mozilla/meta/css/white-space-pre-wrap.htm.ini
@@ -0,0 +1,2 @@
+[white-space-pre-wrap.htm]
+  expected: FAIL