From c5ca503d92a25dc168f84b9d7c008c390f434667 Mon Sep 17 00:00:00 2001
From: Jean-Marc Lasgouttes <lasgouttes@lyx.org>
Date: Tue, 20 Mar 2018 16:41:59 +0100
Subject: [PATCH] Makes caret height adapt to context in mathed.

Set current cursor font in MathData::metrics()

Also make sure that caret dimension in mathed is not larger than inset
height.
---
 src/BufferView.cpp      | 12 ++++++++++--
 src/mathed/MathData.cpp |  9 +++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/BufferView.cpp b/src/BufferView.cpp
index 0e30cc795c..dafcc9d194 100644
--- a/src/BufferView.cpp
+++ b/src/BufferView.cpp
@@ -2965,8 +2965,16 @@ void BufferView::caretPosAndHeight(Point & p, int & h) const
 	Cursor const & cur = cursor();
 	Font const font = cur.real_current_font;
 	frontend::FontMetrics const & fm = theFontMetrics(font);
-	int const asc = fm.maxAscent();
-	int const des = fm.maxDescent();
+	int asc = fm.maxAscent();
+	int des = fm.maxDescent();
+	// If the cursor is in mathed and it has cached metrics, reduce
+	// the height to fit the inner cell (mathed cells are tight
+	// vertically).
+	if (cur.inMathed() && coordCache().getArrays().hasDim(&cur.cell())) {
+		Dimension const dim = cur.cell().dimension(*this);
+		asc = min(asc, dim.asc);
+		des = min(des, dim.des);
+	}
 	h = asc + des;
 	p = getPos(cur);
 	p.y_ -= asc;
diff --git a/src/mathed/MathData.cpp b/src/mathed/MathData.cpp
index d242a86f72..96aef29491 100644
--- a/src/mathed/MathData.cpp
+++ b/src/mathed/MathData.cpp
@@ -261,6 +261,15 @@ bool isInside(DocIterator const & it, MathData const & ar,
 
 void MathData::metrics(MetricsInfo & mi, Dimension & dim) const
 {
+	// This is the only point where the drawing font is known.
+	// We set cursor current font so that the blinking caret height
+	// adapts to math font.
+	Cursor & cur = mi.base.bv->cursor();
+	if (cur.inMathed() && &cur.cell() == this) {
+		cur.current_font.fontInfo() = mi.base.font;
+		cur.real_current_font.fontInfo() = mi.base.font;
+	}
+
 	frontend::FontMetrics const & fm = theFontMetrics(mi.base.font);
 	dim = fm.dimension('I');
 	int xascent = fm.dimension('x').ascent();
-- 
2.39.2