[patch] another solution for Bidi cursor movement in Mathed

[Elazar Leibovich]

Please try this patch for second approach. Please make sure I'm not
breaking anything.
See discussion here http://bugzilla.lyx.org/show_bug.cgi?id=3551

Index: Text2.cpp
===================================================================
--- Text2.cpp	(revision 18129)
+++ Text2.cpp	(working copy)
@@ -915,8 +915,12 @@
 
 bool Text::cursorLeft(Cursor & cur)
 {
+	bool direction = false;
+	if (isRTL(*cur.bv().buffer(), cur.paragraph()))
+		direction = !direction;
 	// Tell BufferView to test for FitCursor in any case!
 	cur.updateFlags(Update::FitCursor);
+	
 
 	if (!cur.boundary() && cur.pos() > 0 &&
 	    cur.textRow().pos() == cur.pos() &&
@@ -926,7 +930,7 @@
 	}
 	if (cur.pos() != 0) {
 		bool updateNeeded = setCursor(cur, cur.pit(), cur.pos() - 1, true, false);
-		if (!checkAndActivateInset(cur, false)) {
+		if (!checkAndActivateInset(cur, direction)) {
 			/** FIXME: What's this cause purpose???
 			bool boundary = cur.boundary();
 			if (false && !boundary &&
@@ -949,6 +953,9 @@
 bool Text::cursorRight(Cursor & cur)
 {
 	// Tell BufferView to test for FitCursor in any case!
+	bool direction = true;
+	if (isRTL(*cur.bv().buffer(), cur.paragraph()))
+		direction = !direction;	
 	cur.updateFlags(Update::FitCursor);
 
 	if (cur.pos() != cur.lastpos()) {
@@ -957,7 +964,7 @@
 					 true, false);
 
 		bool updateNeeded = false;
-		if (!checkAndActivateInset(cur, true)) {
+		if (!checkAndActivateInset(cur, direction)) {
 			if (cur.textRow().endpos() == cur.pos() + 1 &&
 			    cur.textRow().endpos() != cur.lastpos() &&
 			    !cur.paragraph().isLineSeparator(cur.pos()) &&
Index: Cursor.cpp
===================================================================
--- Cursor.cpp	(revision 18129)
+++ Cursor.cpp	(working copy)
@@ -360,10 +360,14 @@
 {
 	BOOST_ASSERT(!empty());
 	//lyxerr << "Leaving inset to the left" << endl;
+	const pos_type lp = (depth() > 1) ? (*this)[depth() - 2].lastpos() : 0;
 	inset().notifyCursorLeaves(*this);
 	if (depth() == 1)
 		return false;
 	pop();
+	if (depth() == 1 && isRTL()) {
+		pos() += lastpos() - lp + 1;
+	}
 	return true;
 }
 
@@ -376,8 +380,11 @@
 	inset().notifyCursorLeaves(*this);
 	if (depth() == 1)
 		return false;
+	
 	pop();
-	pos() += lastpos() - lp + 1;
+	if (!(depth() == 1 && isRTL())) {
+		pos() += lastpos() - lp + 1;
+	}
 	return true;
 }