From 2d665dbc1ba58db55c486597c62f44e50128a5da Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Fri, 9 Jun 2017 11:42:35 -0400
Subject: [PATCH] Ignore Ctrl and Alt if both are present (e.g. AltGr on
 Windows) (see #4096)

---
 modules/lib/d3.keybinding.js   |  6 ++++--
 test/spec/lib/d3.keybinding.js | 24 ++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/modules/lib/d3.keybinding.js b/modules/lib/d3.keybinding.js
index 443f0dfe4..9094a2ba8 100644
--- a/modules/lib/d3.keybinding.js
+++ b/modules/lib/d3.keybinding.js
@@ -66,8 +66,10 @@ export function d3keybinding(namespace) {
             }
 
             // test modifier keys
-            if (event.ctrlKey !== binding.event.modifiers.ctrlKey) return false;
-            if (event.altKey !== binding.event.modifiers.altKey) return false;
+            if (!(event.ctrlKey && event.altKey)) {  // if both are set, assume AltGr and skip it - #4096
+                if (event.ctrlKey !== binding.event.modifiers.ctrlKey) return false;
+                if (event.altKey !== binding.event.modifiers.altKey) return false;
+            }
             if (event.metaKey !== binding.event.modifiers.metaKey) return false;
             if (testShift && event.shiftKey !== binding.event.modifiers.shiftKey) return false;
 
diff --git a/test/spec/lib/d3.keybinding.js b/test/spec/lib/d3.keybinding.js
index 62f45118b..c4ce6a5da 100644
--- a/test/spec/lib/d3.keybinding.js
+++ b/test/spec/lib/d3.keybinding.js
@@ -38,6 +38,30 @@ describe('d3.keybinding', function() {
             expect(spy).to.have.been.calledOnce;
         });
 
+        it('matches the binding even when shift is present', function () {
+            d3.select(document).call(keybinding.on('A', spy));
+
+            happen.keydown(document, {keyCode: 65, shiftKey: true});
+            expect(spy).to.have.been.calledOnce;
+        });
+
+        it('matches shifted bindings before unshifted bindings', function () {
+            var spy2 = sinon.spy();
+            d3.select(document).call(keybinding.on('A', spy2));
+            d3.select(document).call(keybinding.on('⇧A', spy));
+
+            happen.keydown(document, {keyCode: 65, shiftKey: true});
+            expect(spy).to.have.been.calledOnce;
+            expect(spy2).not.to.have.been.called;
+        });
+
+        it('ignores alt and control if both are present (e.g. as AltGr) #4096', function () {
+            d3.select(document).call(keybinding.on('A', spy));
+
+            happen.keydown(document, {keyCode: 65, altKey: true, ctrlKey: true});
+            expect(spy).to.have.been.calledOnce;
+        });
+
         it('adds multiple bindings given an array of keys', function () {
             d3.select(document).call(keybinding.on(['A','B'], spy));