[LyX/master] Fix display of emphasize in slanted text

[Jean-Marc Lasgouttes]

commit 610ea7f4f503d690287c75fc5e8b003e1d7b5c96
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Sun Mar 7 13:29:21 2021 +0100

    Fix display of emphasize in slanted text
    
    Fixes bug #12175.
---
 src/FontInfo.h |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/src/FontInfo.h b/src/FontInfo.h
index 42eea31..3feefca 100644
--- a/src/FontInfo.h
+++ b/src/FontInfo.h
@@ -129,7 +129,8 @@ public:
 		if (noun_ == FONT_ON)
 			return SMALLCAPS_SHAPE;
 		if (emph_ == FONT_ON)
-			return (shape_ == ITALIC_SHAPE) ? UP_SHAPE : ITALIC_SHAPE;
+			return (shape_ == ITALIC_SHAPE || shape_ == SLANTED_SHAPE)
+				? UP_SHAPE : ITALIC_SHAPE;
 		return shape_;
 	}