[LyX/master] Let InsetSpecialChar draw its background when necessary

[Jean-Marc Lasgouttes]

commit 63cf3297f8e9a45a582d80ebe23f8f6802bcb368
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date:   Thu Aug 4 23:20:18 2016 +0200

    Let InsetSpecialChar draw its background when necessary
    
    This is the same fix as in 9940acc5 for auote inset and math macro template.
---
 src/insets/InsetSpecialChar.cpp |   10 ++++++++++
 src/insets/InsetSpecialChar.h   |    2 ++
 2 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/src/insets/InsetSpecialChar.cpp b/src/insets/InsetSpecialChar.cpp
index 3d32f40..6554cce 100644
--- a/src/insets/InsetSpecialChar.cpp
+++ b/src/insets/InsetSpecialChar.cpp
@@ -134,6 +134,16 @@ void InsetSpecialChar::metrics(MetricsInfo & mi, Dimension 
& dim) const
 }
 
 
+void InsetSpecialChar::drawBackground(PainterInfo & pi, int x, int y) const
+{
+       if (pi.full_repaint)
+               return;
+       Dimension const dim = dimension(*pi.base.bv);
+       pi.pain.fillRectangle(x, y - dim.asc, dim.wid, dim.asc + dim.des,
+                             pi.backgroundColor(this));
+}
+
+
 namespace {
 
 // helper function: draw text and update x.
diff --git a/src/insets/InsetSpecialChar.h b/src/insets/InsetSpecialChar.h
index a576186..a57f9df 100644
--- a/src/insets/InsetSpecialChar.h
+++ b/src/insets/InsetSpecialChar.h
@@ -61,6 +61,8 @@ public:
        ///
        void metrics(MetricsInfo &, Dimension &) const;
        ///
+       void drawBackground(PainterInfo & pi, int x, int y) const;
+       ///
        void draw(PainterInfo & pi, int x, int y) const;
        ///
        void write(std::ostream &) const;