diff --git a/components/gfx/text/shaping/harfbuzz.rs b/components/gfx/text/shaping/harfbuzz.rs
index eb1a6cfb87cf..f8ad5ef4a6c6 100644
--- a/components/gfx/text/shaping/harfbuzz.rs
+++ b/components/gfx/text/shaping/harfbuzz.rs
@@ -521,6 +521,9 @@ impl Shaper {
// We elect to only space the two required code points.
if character == ' ' || character == '\u{a0}' {
advance = advance + options.word_spacing
+ } else if character == '\t' {
+ let tab_size = 8f64;
+ advance = Au::from_frac_px(tab_size * glyph_space_advance(self.font_and_shaping_options.font));
}
advance
@@ -563,6 +566,19 @@ extern fn glyph_h_advance_func(_: *mut hb_font_t,
}
}
+fn glyph_space_advance(font: *mut Font) -> f64 {
+ let space_unicode = ' ';
+ let space_glyph: hb_codepoint_t;
+ match unsafe {(*font).glyph_index(space_unicode)} {
+ Some(g) => {
+ space_glyph = g as hb_codepoint_t;
+ }
+ None => panic!("No space info")
+ }
+ let space_advance = unsafe {(*font).glyph_h_advance(space_glyph as GlyphId)};
+ space_advance
+}
+
extern fn glyph_h_kerning_func(_: *mut hb_font_t,
font_data: *mut c_void,
first_glyph: hb_codepoint_t,
diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index c66e6750ad50..373c4a2fe65c 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -245,6 +245,7 @@ experimental != overconstrained_block.html overconstrained_block_ref.html
== position_relative_a.html position_relative_b.html
== position_relative_top_percentage_a.html position_relative_top_percentage_b.html
== pre_ignorable_whitespace_a.html pre_ignorable_whitespace_ref.html
+== pre_with_tab.html pre_with_tab_ref.html
== pseudo_element_a.html pseudo_element_b.html
== pseudo_inherit.html pseudo_inherit_ref.html
== quotes_simple_a.html quotes_simple_ref.html
diff --git a/tests/ref/pre_with_tab.html b/tests/ref/pre_with_tab.html
new file mode 100644
index 000000000000..b5bfcf42fa22
--- /dev/null
+++ b/tests/ref/pre_with_tab.html
@@ -0,0 +1 @@
+ tab
diff --git a/tests/ref/pre_with_tab_ref.html b/tests/ref/pre_with_tab_ref.html
new file mode 100644
index 000000000000..a0b8d6d8e93b
--- /dev/null
+++ b/tests/ref/pre_with_tab_ref.html
@@ -0,0 +1 @@
+ tab