[pango/fix-strikethrough-averaging] renderer: Fix averaging of strikethroughs

[Matthias Clasen <matthiasc src gnome org>]

commit 7549d36af2e79ebd86ae9cc05a86bfdc22dfebf8
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Jul 5 19:16:25 2021 -0400

    renderer: Fix averaging of strikethroughs
    
    In 85bdfead1b36945db251 I made consecutive runs average
    their strikeout positions, but I did handle the accounting
    properly, causing previous runs to influence the strikeout
    of later runs, if we have to draw them separately (due to
    color change).
    
    It would be nicer to average even across color changes and
    draw the line continuously in that case as well, but that
    would require two passes over the runs.
    
    Fixes: #574

 pango/pango-renderer.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)
---
diff --git a/pango/pango-renderer.c b/pango/pango-renderer.c
index 49eec91d..f575707f 100644
--- a/pango/pango-renderer.c
+++ b/pango/pango-renderer.c
@@ -282,18 +282,22 @@ draw_strikethrough (PangoRenderer *renderer,
                     LineState     *state)
 {
   PangoRectangle *rect = &state->strikethrough_rect;
-  gboolean strikethrough = state->strikethrough;
   int num_glyphs = state->strikethrough_glyphs;
 
-  state->strikethrough = FALSE;
-
-  if (strikethrough)
+  if (state->strikethrough)
     pango_renderer_draw_rectangle (renderer,
                                    PANGO_RENDER_PART_STRIKETHROUGH,
                                    rect->x,
                                    rect->y / num_glyphs,
                                    rect->width,
                                    rect->height / num_glyphs);
+
+  state->strikethrough = FALSE;
+  state->strikethrough_glyphs = 0;
+  rect->x += rect->width;
+  rect->width = 0;
+  rect->y = 0;
+  rect->height = 0;
 }
 
 static void
@@ -336,8 +340,6 @@ handle_line_state_change (PangoRenderer  *renderer,
       rect->width = state->logical_rect_end - rect->x;
       draw_strikethrough (renderer, state);
       state->strikethrough = renderer->strikethrough;
-      rect->x = state->logical_rect_end;
-      rect->width = 0;
     }
 }
 
@@ -484,7 +486,6 @@ add_strikethrough (PangoRenderer    *renderer,
     }
   else
     {
-      draw_strikethrough (renderer, state);
       *current_rect = new_rect;
       state->strikethrough = TRUE;
       state->strikethrough_glyphs = num_glyphs;