From 585a38aa921783d78dd8aeb55a173a0ad3b9395b Mon Sep 17 00:00:00 2001
From: Emily KL <4672118+emilykl@users.noreply.github.com>
Date: Mon, 8 Dec 2025 16:39:42 -0500
Subject: [PATCH 1/4] fix issue where some scatter traces would lose fill after
 series of hide/show operations in legend

---
 src/traces/scatter/plot.js | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/traces/scatter/plot.js b/src/traces/scatter/plot.js
index f22a75fbfd5..66abb9a015e 100644
--- a/src/traces/scatter/plot.js
+++ b/src/traces/scatter/plot.js
@@ -83,6 +83,9 @@ function createFills(gd, traceJoin, plotinfo) {
 
         var trace = d[0].trace;
 
+        trace._ownFill = null;
+        trace._nextFill = null;
+
         var fillData = [];
         if(trace._ownfill) fillData.push('_ownFill');
         if(trace._nexttrace) fillData.push('_nextFill');
@@ -91,9 +94,7 @@ function createFills(gd, traceJoin, plotinfo) {
 
         fillJoin.enter().append('g');
 
-        fillJoin.exit()
-            .each(function(d) { trace[d] = null; })
-            .remove();
+        fillJoin.exit().remove();
 
         fillJoin.order().each(function(d) {
             // make a path element inside the fill group, just so

From 2a24c58417b2158087408b6b7fbfd4fe7d0c68c9 Mon Sep 17 00:00:00 2001
From: Emily KL <4672118+emilykl@users.noreply.github.com>
Date: Mon, 8 Dec 2025 16:45:46 -0500
Subject: [PATCH 2/4] add jasmine test

---
 test/jasmine/tests/scatter_test.js | 44 ++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/test/jasmine/tests/scatter_test.js b/test/jasmine/tests/scatter_test.js
index 8a3739d0d69..4c27d0a9bb8 100644
--- a/test/jasmine/tests/scatter_test.js
+++ b/test/jasmine/tests/scatter_test.js
@@ -1361,6 +1361,50 @@ describe('stacked area', function() {
         })
         .then(done, done.fail);
     });
+
+    it('maintains correct fill elements when toggling trace visibility in stacked area charts', function(done) {
+        // Regression test for issue #7660
+        // When isolating, then hiding all, then showing all traces in a stacked area chart,
+        // fill elements should be correctly drawn for all traces.
+
+        function countNonEmptyFills() {
+            return d3SelectAll('.scatterlayer .js-fill').filter(function() {
+                var d = d3Select(this).attr('d');
+                return d && d !== 'M0,0Z';
+            }).size();
+        }
+
+        Plotly.newPlot(gd, [
+            {x: [1, 2, 3], y: [2, 1, 4], stackgroup: 'one', name: 'trace 0'},
+            {x: [1, 2, 3], y: [1, 1, 2], stackgroup: 'one', name: 'trace 1'},
+            {x: [1, 2, 3], y: [3, 0, 2], stackgroup: 'one', name: 'trace 2'}
+        ])
+        .then(function() {
+            // Initially all 3 traces should be visible with fills
+            expect(countNonEmptyFills()).toBe(3, 'should have 3 fill paths initially');
+
+            // Show trace 1 only
+            return Plotly.restyle(gd, 'visible', ['legendonly', true, 'legendonly']);
+        })
+        .then(function() {
+            // Verify only one fill is drawn (trace 1)
+            expect(countNonEmptyFills()).toBe(1, 'should have 1 fill path when isolating trace 1');
+            // Hide all traces
+            return Plotly.restyle(gd, 'visible', ['legendonly', 'legendonly', 'legendonly']);
+        })
+        .then(function() {
+            // Verify no fills are drawn
+            expect(countNonEmptyFills()).toBe(0, 'should have 0 fill paths when hiding all traces');
+            // Show all traces again
+            return Plotly.restyle(gd, 'visible', [true, true, true]);
+        })
+        .then(function() {
+            // Verify all 3 fills are drawn again
+            // This is the step that was failing in #7660
+            expect(countNonEmptyFills()).toBe(3, 'should have 3 fill paths after showing all traces again');
+        })
+        .then(done, done.fail);
+    });
 });
 
 describe('scatter hoverPoints', function() {

From ebbbe3821ec70cf6e7f0dbe8fe149f7ea8d94350 Mon Sep 17 00:00:00 2001
From: Emily KL <4672118+emilykl@users.noreply.github.com>
Date: Tue, 27 Jan 2026 11:46:29 -0500
Subject: [PATCH 3/4] add explanatory comment

---
 src/traces/scatter/plot.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/traces/scatter/plot.js b/src/traces/scatter/plot.js
index 66abb9a015e..3c9e19df936 100644
--- a/src/traces/scatter/plot.js
+++ b/src/traces/scatter/plot.js
@@ -83,6 +83,11 @@ function createFills(gd, traceJoin, plotinfo) {
 
         var trace = d[0].trace;
 
+        // trace._ownFill and trace._nextFill may have leftover values
+        // from a previous call to createFills. They should always start as null.
+        // We clear both values in order to start with a clean slate.
+        // Note that these are DIFFERENT VARIABLES than
+        // trace._ownfill and trace._nexttrace referenced a few lines down.
         trace._ownFill = null;
         trace._nextFill = null;
 

From 0cd58d14445e30470d5b145bc836a28de00b7c1f Mon Sep 17 00:00:00 2001
From: Emily KL <4672118+emilykl@users.noreply.github.com>
Date: Tue, 27 Jan 2026 11:50:55 -0500
Subject: [PATCH 4/4] add draftlog

---
 draftlogs/7668_fix.md | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 draftlogs/7668_fix.md

diff --git a/draftlogs/7668_fix.md b/draftlogs/7668_fix.md
new file mode 100644
index 00000000000..7af1a8dc2ed
--- /dev/null
+++ b/draftlogs/7668_fix.md
@@ -0,0 +1 @@
+ - Fix issue where some traces in stacked area charts were not rendering their fill correctly after certain sequences of hide/show operations in the legend [[#7668](https://github.com/plotly/plotly.js/pull/7668)]
\ No newline at end of file