Merge branch 'more-space-tweaks' into 'main'

shape: More tweaks to space handling

See merge request GNOME/pango!557

4 files changed, 50 insertions, 20 deletions

diff --git a/pango/pangocairo-font.c b/pango/pangocairo-font.c
index c2bcc51b..02a976d8 100644
--- a/pango/pangocairo-font.c
+++ b/pango/pangocairo-font.c
@@ -676,27 +676,45 @@ get_space_extents (PangoCairoFontPrivate *cf_priv,
                    PangoRectangle        *ink_rect,
                    PangoRectangle        *logical_rect)
 {
+  cairo_scaled_font_t *scaled_font;
   const char hexdigits[] = "0123456789ABCDEF";
   char c[2] = {0, 0};
   int i;
   double hex_width;
   int width;
+  int n_chars;
 
   /* we don't render missing spaces as hex boxes,
    * so come up with some width to use. For lack
    * of anything better, use average hex digit width.
    */
 
+  scaled_font = _pango_cairo_font_private_get_scaled_font (cf_priv);
   hex_width = 0;
+  n_chars = 0;
   for (i = 0 ; i < 16 ; i++)
     {
       cairo_text_extents_t extents;
 
       c[0] = hexdigits[i];
-      cairo_scaled_font_text_extents (_pango_cairo_font_private_get_scaled_font (cf_priv), c, &extents);
-      hex_width += extents.width;
+      cairo_scaled_font_text_extents (scaled_font, c, &extents);
+      if (extents.width > 0)
+        {
+          hex_width += extents.width;
+          n_chars++;
+        }
+    }
+
+  if (n_chars == 0)
+    {
+      cairo_font_extents_t extents;
+
+      cairo_scaled_font_extents (scaled_font, &extents);
+      hex_width += extents.max_x_advance;
+      n_chars++;
     }
-  width = pango_units_from_double (hex_width / 16);
+
+  width = pango_units_from_double (hex_width / n_chars);
 
   if (ink_rect)
     {
diff --git a/pango/shape.c b/pango/shape.c
index 90334cc1..30bceb80 100644
--- a/pango/shape.c
+++ b/pango/shape.c
@@ -137,12 +137,24 @@ pango_hb_font_get_nominal_glyph (hb_font_t      *font,
   if (hb_font_get_nominal_glyph (context->parent, unicode, glyph))
     return TRUE;
 
-  /* HarfBuzz knows how to synthesize spaces, so never replace them
-   * with unknown glyphs, but we do need to tell HarfBuzz that the
-   * font does not have a glyph.
+  /* HarfBuzz knows how to synthesize other spaces from 0x20, so never
+   * replace them with unknown glyphs, just tell HarfBuzz that we don't
+   * have a glyph.
+   *
+   * For 0x20, on the other hand, we need to pretend that we have a glyph
+   * and rely on our glyph extents code to provide a reasonable width for
+   * PANGO_GET_UNKNOWN_WIDTH (0x20).
    */
   if (g_unichar_type (unicode) == G_UNICODE_SPACE_SEPARATOR)
-    return FALSE;
+    {
+      if (unicode == 0x20)
+        {
+          *glyph = PANGO_GET_UNKNOWN_GLYPH (0x20);
+          return TRUE;
+        }
+
+      return FALSE;
+    }
 
   *glyph = PANGO_GET_UNKNOWN_GLYPH (unicode);
 
diff --git a/tests/layouts/no-space.layout b/tests/layouts/no-space.layout
index 07f6aa06..12f878f6 100644
--- a/tests/layouts/no-space.layout
+++ b/tests/layouts/no-space.layout
@@ -20,9 +20,9 @@
   "output" : {
     "is-wrapped" : false,
     "is-ellipsized" : false,
-    "unknown-glyphs" : 0,
-    "width" : 220160,
-    "height" : 220160,
+    "unknown-glyphs" : 4,
+    "width" : 261120,
+    "height" : 261120,
     "log-attrs" : [
       {
         "char-break" : true,
@@ -104,14 +104,14 @@
             "end-x-offset" : 0,
             "glyphs" : [
               {
-                "glyph" : 0,
-                "width" : 44032,
+                "glyph" : 268435488,
+                "width" : 54272,
                 "is-cluster-start" : true,
                 "log-cluster" : 0
               },
               {
-                "glyph" : 0,
-                "width" : 44032,
+                "glyph" : 268435488,
+                "width" : 54272,
                 "is-cluster-start" : true,
                 "log-cluster" : 1
               },
@@ -122,14 +122,14 @@
                 "log-cluster" : 2
               },
               {
-                "glyph" : 0,
-                "width" : 44032,
+                "glyph" : 268435488,
+                "width" : 54272,
                 "is-cluster-start" : true,
                 "log-cluster" : 5
               },
               {
-                "glyph" : 0,
-                "width" : 44032,
+                "glyph" : 268435488,
+                "width" : 54272,
                 "is-cluster-start" : true,
                 "log-cluster" : 6
               }
diff --git a/tests/layouts/valid-14.layout b/tests/layouts/valid-14.layout
index 9bfd7723..69d061b0 100644
--- a/tests/layouts/valid-14.layout
+++ b/tests/layouts/valid-14.layout
@@ -23,7 +23,7 @@
   "output" : {
     "is-wrapped" : false,
     "is-ellipsized" : true,
-    "unknown-glyphs" : 0,
+    "unknown-glyphs" : 1,
     "width" : 161792,
     "height" : 161792,
     "log-attrs" : [
@@ -266,7 +266,7 @@
             "end-x-offset" : 0,
             "glyphs" : [
               {
-                "glyph" : 0,
+                "glyph" : 268435488,
                 "width" : 15360,
                 "is-cluster-start" : true,
                 "log-cluster" : 0