Use shape flags for tab width

We need to apply the right shape flags to the tab width calculation,
otherwise (when glyph positions get rounded, which is the default) our
tab width will be slightly off from what 8 spaces normally produce.

https://gitlab.gnome.org/GNOME/pango/issues/425

1 files changed, 5 insertions, 1 deletions

diff --git a/pango/pango-layout.c b/pango/pango-layout.c
index 44d59367..643f5623 100644
--- a/pango/pango-layout.c
+++ b/pango/pango-layout.c
@@ -3061,6 +3061,10 @@ ensure_tab_width (PangoLayout *layout)
       PangoAttrIterator *iter;
       PangoFontDescription *font_desc = pango_font_description_copy_static (pango_context_get_font_description (layout->context));
       PangoLanguage *language;
+      PangoShapeFlags shape_flags = PANGO_SHAPE_NONE;
+
+      if (pango_context_get_round_glyph_positions (layout->context))
+        shape_flags |= PANGO_SHAPE_ROUND_POSITIONS;
 
       layout_attrs = pango_layout_get_effective_attributes (layout);
       iter = pango_attr_list_get_iterator (layout_attrs);
@@ -3089,7 +3093,7 @@ ensure_tab_width (PangoLayout *layout)
       pango_attr_list_unref (tmp_attrs);
 
       item = items->data;
-      pango_shape ("        ", 8, &item->analysis, glyphs);
+      pango_shape_with_flags ("        ", 8, "        ", 8, &item->analysis, glyphs, shape_flags);
 
       pango_item_free (item);
       g_list_free (items);