From 2bc1229fb9242aa0f6f373ec800aef519e955b71 Mon Sep 17 00:00:00 2001
From: Jamie Peabody <jamie.peabody@gmail.com>
Date: Sat, 4 Nov 2017 10:49:48 +0000
Subject: [PATCH] issue-69: invalidates current set of changes before editor
 content is replaced

---
 lib/mergely.css | 10 +++++++---
 lib/mergely.js  | 12 +++++++++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/lib/mergely.css b/lib/mergely.css
index ab257f7..d98a025 100644
--- a/lib/mergely.css
+++ b/lib/mergely.css
@@ -18,12 +18,12 @@
 .mergely.a.lhs.start.end,
 .mergely.a.rhs.end { border-bottom: 1px solid #a3d1ff; }
 .mergely.a.rhs { background-color: #ddeeff; }
-.mergely.a.lhs.start.end.first { border-bottom: 0; border-top: 1px solid #a3d1ff; }
+.mergely.a.lhs.start.end.first { border-bottom-width: 0; border-top: 1px solid #a3d1ff; }
 
 .mergely.d.lhs { background-color: #ffe9e9; }
 .mergely.d.lhs.end,
 .mergely.d.rhs.start.end { border-bottom: 1px solid #f8e8e8; }
-.mergely.d.rhs.start.end.first { border-bottom: 0; border-top: 1px solid #f8e8e8; }
+.mergely.d.rhs.start.end.first { border-bottom-width: 0; border-top: 1px solid #f8e8e8; }
 .mergely.d.lhs.start { border-top: 1px solid #f8e8e8; }
 
 .mergely.c.lhs,
@@ -39,7 +39,11 @@
 .mergely.current.start { border-top: 1px solid #000 !important; }
 .mergely.current.end { border-bottom: 1px solid #000 !important; }
 .mergely.current.lhs.a.start.end,
-.mergely.current.rhs.d.start.end { border-top: 0 !important; }
+.mergely.current.rhs.d.start.end { border-top-width: 0 !important; }
+
+.mergely.current.lhs.a.start.end.empty,
+.mergely.current.rhs.d.start.end.empty { border-top-width: 1px !important; border-bottom-width: 0px !important; }
+
 .mergely.current.CodeMirror-linenumber { color: #F9F9F9; font-weight: bold; background-color: #777; }
 .CodeMirror-linenumber { cursor: pointer; }
 .CodeMirror-code { color: #717171; }
diff --git a/lib/mergely.js b/lib/mergely.js
index 3d0bf23..2e474c5 100644
--- a/lib/mergely.js
+++ b/lib/mergely.js
@@ -484,9 +484,11 @@ jQuery.extend(Mgly.CodeMirrorDiffView.prototype, {
 		this.unbind();
 	},
 	lhs: function(text) {
+		this.changes = []; // invalidate existing changes
 		this.editor[this.id + '-lhs'].setValue(text);
 	},
 	rhs: function(text) {
+		this.changes = []; // invalidate existing changes
 		this.editor[this.id + '-rhs'].setValue(text);
 	},
 	update: function() {
@@ -796,7 +798,9 @@ jQuery.extend(Mgly.CodeMirrorDiffView.prototype, {
 		// set cursors
 		led.setCursor(Math.max(change["lhs-line-from"],0), 0); // use led.getCursor().ch ?
 		red.setCursor(Math.max(change["rhs-line-from"],0), 0);
-		led.scrollIntoView({line: change["lhs-line-to"]});
+		if (change["lhs-line-to"] >= 0) {
+			led.scrollIntoView({line: change["lhs-line-to"]});
+		}
 	},
 
 	_scrolling: function(editor_name) {
@@ -1173,6 +1177,9 @@ jQuery.extend(Mgly.CodeMirrorDiffView.prototype, {
 				var clazz = ['mergely', 'lhs', change['op'], 'cid-' + i];
 				led.addLineClass(llf, 'background', 'start');
 				led.addLineClass(llt, 'background', 'end');
+				if (change['lhs-line-from'] < 0) {
+					clazz.push('empty');
+				}
 
 				if (current_diff == i) {
 					if (llf != llt) {
@@ -1225,6 +1232,9 @@ jQuery.extend(Mgly.CodeMirrorDiffView.prototype, {
 				var clazz = ['mergely', 'rhs', change['op'], 'cid-' + i];
 				red.addLineClass(rlf, 'background', 'start');
 				red.addLineClass(rlt, 'background', 'end');
+				if (change['rhs-line-from'] < 0) {
+					clazz.push('empty');
+				}
 
 				if (current_diff == i) {
 					if (rlf != rlt) {