fix #5025 part 1

cairo line may be rounded +-1 px, also invalidating area x<0 is a noop.

git-svn-id: svn://localhost/ardour2/branches/3.0@13493 d708f5d6-7413-0410-9779-e7cbd77b26cf

diff --git a/gtk2_ardour/editor_summary.cc b/gtk2_ardour/editor_summary.cc
index 7ce74f414b2b3216560e856bd96d66f8d4ba712d..0cf58cf8ae2c5ae27b9455e8bbc2dab9954b14cc 100644 (file)
--- a/gtk2_ardour/editor_summary.cc
+++ b/gtk2_ardour/editor_summary.cc
@@ -906,9 +906,9 @@ EditorSummary::playhead_position_changed (framepos_t p)
        int const o = int (_last_playhead);
        int const n = int (playhead_frame_to_position (p));
        if (_session && o != n) {
-               int a = min (o, n);
+               int a = max(2, min (o, n));
                int b = max (o, n);
-               set_overlays_dirty (a - 1, 0, b + 1, get_height ());
+               set_overlays_dirty (a - 2, 0, b + 2, get_height ());
        }
 }