Avoid blinking change tracking cur for math inset.

Since there is a margin above and below the inset, there is no problem
for putting it higher.

Fixes bug #11684.

(cherry picked from commit bf7f4d716cf0ef148495d7ecd616a1aaea57a13d)

src/mathed/InsetMathHull.cpp

@@ -692,9 +692,12 @@ void InsetMathHull::draw(PainterInfo & pi, int x, int y) const
 	}
 
 	// drawing change line
-	if (canPaintChange(*bv))
-		pi.change_.paintCue(pi, x + 1, y + 1 - dim.asc,
-		                    x + dim.wid, y + dim.des);
+	if (canPaintChange(*bv)) {
+		// like in metrics()
+		int const display_margin = display() ? displayMargin() : 0;
+		pi.change_.paintCue(pi, x + 1, y + 1 - dim.asc + display_margin,
+		                    x + dim.wid, y + dim.des - display_margin);
+	}
 }
 
 

status.23x

@@ -44,6 +44,8 @@ What's new
 
 * USER INTERFACE
 
+- Fix display glith where the change tracking cue blinks with the cursor
+  (bug 11684).
 
 * INTERNALS