Fix display of strike-through text in variable-height lines

* src/nsterm.m (ns_draw_text_decoration):
* src/xterm.c (x_draw_glyph_string):
* src/w32term.c (x_draw_glyph_string): Fix calculation of the
strike-through y-coordinate for a glyph row which is taller than
the strike-through text.  (Bug#25907)

3 files changed, 37 insertions, 10 deletions

diff --git a/src/nsterm.m b/src/nsterm.m
index 28764c8a4fb..eaefea79855 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -3107,10 +3107,19 @@ ns_draw_text_decoration (struct glyph_string *s, struct face *face,
   if (face->strike_through_p)
     {
       NSRect r;
+      /* Y-coordinate and height of the glyph string's first glyph.
+         We cannot use s->y and s->height because those could be
+         larger if there are taller display elements (e.g., characters
+         displayed with a larger font) in the same glyph row.  */
+      int glyph_y = s->ybase - s->first_glyph->ascent;
+      int glyph_height = s->first_glyph->ascent + s->first_glyph->descent;
+      /* Strike-through width and offset from the glyph string's
+         top edge.  */
+      unsigned long h = 1;
       unsigned long dy;
 
-      dy = lrint ((s->height - 1) / 2);
-      r = NSMakeRect (x, s->y + dy, width, 1);
+      dy = lrint ((glyph_height - h) / 2);
+      r = NSMakeRect (x, glyph_y + dy, width, 1);
 
       if (face->strike_through_color_defaulted_p)
         [defaultCol set];
diff --git a/src/w32term.c b/src/w32term.c
index 3d41c30dfe0..28bf6fb3d9f 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -2500,18 +2500,27 @@ x_draw_glyph_string (struct glyph_string *s)
       if (s->face->strike_through_p
           && !FONT_TEXTMETRIC (s->font).tmStruckOut)
         {
+          /* Y-coordinate and height of the glyph string's first
+             glyph.  We cannot use s->y and s->height because those
+             could be larger if there are taller display elements
+             (e.g., characters displayed with a larger font) in the
+             same glyph row.  */
+          int glyph_y = s->ybase - s->first_glyph->ascent;
+          int glyph_height = s->first_glyph->ascent + s->first_glyph->descent;
+          /* Strike-through width and offset from the glyph string's
+             top edge.  */
           unsigned long h = 1;
-          unsigned long dy = (s->height - h) / 2;
+          unsigned long dy = (glyph_height - h) / 2;
 
           if (s->face->strike_through_color_defaulted_p)
             {
-              w32_fill_area (s->f, s->hdc, s->gc->foreground, s->x, s->y + dy,
-                             s->width, h);
+              w32_fill_area (s->f, s->hdc, s->gc->foreground, s->x,
+                             glyph_y + dy, s->width, h);
             }
           else
             {
               w32_fill_area (s->f, s->hdc, s->face->strike_through_color, s->x,
-                             s->y + dy, s->width, h);
+                             glyph_y + dy, s->width, h);
             }
         }
 
diff --git a/src/xterm.c b/src/xterm.c
index c3af28e571d..24d1702cec0 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -3708,18 +3708,27 @@ x_draw_glyph_string (struct glyph_string *s)
       /* Draw strike-through.  */
       if (s->face->strike_through_p)
         {
-          unsigned long h = 1;
-          unsigned long dy = (s->height - h) / 2;
+          /* Y-coordinate and height of the glyph string's first
+             glyph.  We cannot use s->y and s->height because those
+             could be larger if there are taller display elements
+             (e.g., characters displayed with a larger font) in the
+             same glyph row.  */
+          int glyph_y = s->ybase - s->first_glyph->ascent;
+          int glyph_height = s->first_glyph->ascent + s->first_glyph->descent;
+          /* Strike-through width and offset from the glyph string's
+             top edge.  */
+          unsigned long h = 1;
+          unsigned long dy = (glyph_height - h) / 2;
 
           if (s->face->strike_through_color_defaulted_p)
-            x_fill_rectangle (s->f, s->gc, s->x, s->y + dy,
+            x_fill_rectangle (s->f, s->gc, s->x, glyph_y + dy,
                             s->width, h);
           else
             {
               XGCValues xgcv;
               XGetGCValues (s->display, s->gc, GCForeground, &xgcv);
               XSetForeground (s->display, s->gc, s->face->strike_through_color);
-              x_fill_rectangle (s->f, s->gc, s->x, s->y + dy,
+              x_fill_rectangle (s->f, s->gc, s->x, glyph_y + dy,
                               s->width, h);
               XSetForeground (s->display, s->gc, xgcv.foreground);
             }