NS equivalents of xterm.c and w32term.c changes

* src/nsterm.m (ns_maybe_dumpglyphs_background): Force redraw of
glyph string background also when the font in use claims
preposterously large global height value.  Helps to remove
artifacts left from previous displays when glyphless characters
are displayed as hex code in a box.
(x_new_font): Call get_font_ascent_descent to obtain a reasonable
value for FRAME_LINE_HEIGHT, even when a font claims very large
value for its height.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/nsterm.m b/src/nsterm.m
index 67a03898d13..2806f31155d 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -2928,6 +2928,11 @@ ns_maybe_dumpglyphs_background (struct glyph_string *s, char force_p)
     {
       int box_line_width = max (s->face->box_line_width, 0);
       if (FONT_HEIGHT (s->font) < s->height - 2 * box_line_width
+          /* When xdisp.c ignores FONT_HEIGHT, we cannot trust font
+             dimensions, since the actual glyphs might be much
+             smaller.  So in that case we always clear the rectangle
+             with background color.  */
+          || FONT_TOO_HIGH (s->font)
           || s->font_not_found_p || s->extends_to_end_of_line_p || force_p)
         {
           struct face *face;
@@ -7687,6 +7692,7 @@ x_new_font (struct frame *f, Lisp_Object font_object, int fontset)
 {
   struct font *font = XFONT_OBJECT (font_object);
   EmacsView *view = FRAME_NS_VIEW (f);
+  int font_ascent, font_descent;
 
   if (fontset < 0)
     fontset = fontset_from_font (font_object);
@@ -7701,7 +7707,8 @@ x_new_font (struct frame *f, Lisp_Object font_object, int fontset)
 
   FRAME_BASELINE_OFFSET (f) = font->baseline_offset;
   FRAME_COLUMN_WIDTH (f) = font->average_width;
-  FRAME_LINE_HEIGHT (f) = font->height;
+  get_font_ascent_descent (font, &font_ascent, &font_descent);
+  FRAME_LINE_HEIGHT (f) = font_ascent + font_descent;
 
   /* Compute the scroll bar width in character columns.  */
   if (FRAME_CONFIG_SCROLL_BAR_WIDTH (f) > 0)