From: Jean-Marc Lasgouttes <lasgouttes@lyx.org>
Date: Thu, 20 Sep 2018 20:15:12 +0000 (+0200)
Subject: Avoid crash with cursor down in math
X-Git-Tag: lyx-2.4.0dev-acb2ca7b~3043
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=17576fb83b5a560fb8a1c59ca7051dcb2b165c05;p=features.git

Avoid crash with cursor down in math

This can happen when the inset that contains the cursor is outside of
the screen.

THis is only a workaround. The real solution would be a
processUpdateFlags(FitCursor) call, but the code is not ready for that
yet.

Fixes bug #11296.
---

diff --git a/src/mathed/InsetMathGrid.cpp b/src/mathed/InsetMathGrid.cpp
index cb6f440539..58784ad79b 100644
--- a/src/mathed/InsetMathGrid.cpp
+++ b/src/mathed/InsetMathGrid.cpp
@@ -22,6 +22,7 @@
 #include "Buffer.h"
 #include "BufferParams.h"
 #include "BufferView.h"
+#include "CoordCache.h"
 #include "Cursor.h"
 #include "CutAndPaste.h"
 #include "FuncRequest.h"
@@ -969,7 +970,14 @@ bool InsetMathGrid::idxUpDown(Cursor & cur, bool up) const
 		LASSERT(cur.idx() > 0, return false);
 		--cur.idx();
 	}
-	cur.pos() = cur.cell().x2pos(&cur.bv(), cur.x_target() - cur.cell().xo(cur.bv()));
+	// FIXME: this is only a workaround to avoid a crash if the inset
+	// in not in coord cache. The best would be to force a FitCursor
+	// operation.
+	CoordCache::Arrays const & arraysCache = cur.bv().coordCache().arrays();
+	if (arraysCache.has(&cur.cell()))
+		cur.pos() = cur.cell().x2pos(&cur.bv(), cur.x_target() - cur.cell().xo(cur.bv()));
+	else
+		cur.pos() = 0;
 	return true;
 }