From 3d1e86fcad336ebdebd474d1d75fe3b2c714d4f2 Mon Sep 17 00:00:00 2001
From: Mojtaba Samimi <arch.mojtaba.samimi@gmail.com>
Date: Sun, 8 Jan 2023 16:39:23 -0500
Subject: [PATCH 1/3] fix clear lines - issue 6407

---
 src/traces/scatter/plot.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/traces/scatter/plot.js b/src/traces/scatter/plot.js
index 3a63470687e..6a3bc9ee0d3 100644
--- a/src/traces/scatter/plot.js
+++ b/src/traces/scatter/plot.js
@@ -248,7 +248,7 @@ function plotOne(gd, idx, plotinfo, cdscatter, cdscatterAll, element, transition
                     revpath = thisrevpath + 'Z' + revpath;
                 }
 
-                if(subTypes.hasLines(trace) && pts.length > 1) {
+                if(subTypes.hasLines(trace)) {
                     var el = d3.select(this);
 
                     // This makes the coloring work correctly:

From 1d61cf06ee0b9450207c83c3656c99ba5f9e0b25 Mon Sep 17 00:00:00 2001
From: Mojtaba Samimi <arch.mojtaba.samimi@gmail.com>
Date: Sun, 8 Jan 2023 17:11:39 -0500
Subject: [PATCH 2/3] add test to lock issue 6407

---
 test/jasmine/tests/scatter_test.js | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/test/jasmine/tests/scatter_test.js b/test/jasmine/tests/scatter_test.js
index 570c13aef9a..d6b537535b0 100644
--- a/test/jasmine/tests/scatter_test.js
+++ b/test/jasmine/tests/scatter_test.js
@@ -1035,6 +1035,27 @@ describe('end-to-end scatter tests', function() {
         .then(done, done.fail);
     });
 
+    it('updates line segments on redraw when having null values', function(done) {
+        function checkSegments(exp, msg) {
+            var lineSelection = d3Select(gd).selectAll('.scatterlayer .js-line');
+            expect(lineSelection.size()).toBe(exp, msg);
+        }
+
+        Plotly.newPlot(gd, [{
+            y: [1, null, 2, 3],
+            mode: 'lines+markers'
+        }])
+        .then(function() {
+            checkSegments(2, 'inital');
+
+            return Plotly.relayout(gd, 'xaxis.range', [0, 10]);
+        })
+        .then(function() {
+            checkSegments(2, 'after redraw');
+        })
+        .then(done, done.fail);
+    });
+
     it('correctly autoranges fill tonext traces across multiple subplots', function(done) {
         Plotly.newPlot(gd, [
             {y: [3, 4, 5], fill: 'tonexty'},

From d6bd87c45de8a6d206e91b635120caae4bd72fc7 Mon Sep 17 00:00:00 2001
From: Mojtaba Samimi <arch.mojtaba.samimi@gmail.com>
Date: Mon, 9 Jan 2023 09:42:53 -0500
Subject: [PATCH 3/3] log for PR 6429

---
 draftlogs/6429_fix.md | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 draftlogs/6429_fix.md

diff --git a/draftlogs/6429_fix.md b/draftlogs/6429_fix.md
new file mode 100644
index 00000000000..a6f2f8f205a
--- /dev/null
+++ b/draftlogs/6429_fix.md
@@ -0,0 +1 @@
+ - Fix line redraw (regression introduced in 2.15.0) [[#6429](https://github.com/plotly/plotly.js/pull/6429)]