FIX: GetBindingDisplayString returns empty for composites filtered by group-based binding mask [UUM-141423]

Assets/Tests/InputSystem/CoreTests_Actions.cs

@@ -9238,6 +9238,38 @@ public void Actions_WhenGettingDisplayTextForBindingsOnAction_CompositesAreForma
         Assert.That(action.GetBindingDisplayString(8), Is.EqualTo("Left Shift|Right Shift+A"));
     }
 
+    // https://issuetracker.unity3d.com/product/unity/issues/guid/UUM-141423
+    [Test]
+    [Category("Actions")]
+    public void Actions_WhenGettingDisplayTextForBindingsOnAction_CompositeIsIncludedWhenAtLeastOnePartMatchesBindingMask()
+    {
+        var action = new InputAction();
+
+        action.AddCompositeBinding("1DAxis")
+            .With("Negative", "<Keyboard>/a", groups: "Keyboard")
+            .With("Positive", "<Keyboard>/d", groups: "Keyboard");
+
+        Assert.That(action.GetBindingDisplayString(InputBinding.MaskByGroup("Keyboard")),
+            Is.EqualTo("A/D"));
+    }
+
+    // https://issuetracker.unity3d.com/product/unity/issues/guid/UUM-141423
+    [Test]
+    [Category("Actions")]
+    public void Actions_WhenGettingDisplayTextForBindingsOnAction_MixedGroupCompositeIsRenderedAtomicallyWhenAnyPartMatchesBindingMask()
+    {
+        var action = new InputAction();
+
+        action.AddCompositeBinding("1DAxis")
+            .With("Negative", "<Keyboard>/a", groups: "Keyboard")
+            .With("Positive", "<Mouse>/leftButton", groups: "Mouse");
+
+        Assert.That(action.GetBindingDisplayString(InputBinding.MaskByGroup("Keyboard")),
+            Is.EqualTo("A/Left Button"));
+        Assert.That(action.GetBindingDisplayString(InputBinding.MaskByGroup("Mouse")),
+            Is.EqualTo("A/Left Button"));
+    }
+
     // https://fogbugz.unity3d.com/f/cases/1321175/
     [Test]
     [Category("Actions")]

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Fixed
 
+- Fixed `InputActionRebindingExtensions.GetBindingDisplayString(InputAction, InputBinding, ...)` returning an empty string for composite bindings when the binding mask filters by group [UUM-141423](https://issuetracker.unity3d.com/product/unity/issues/guid/UUM-141423)
 - Fixed a `NullReferenceException` thrown when removing all action maps [UUM-137116](https://jira.unity3d.com/browse/UUM-137116)
 - Simplified default setting messaging by consolidating repetitive messages into a single HelpBox.
 - Fixed a `NullPointerReferenceException` thrown in `InputManagerStateMonitors.FireStateChangeNotifications` logging by adding validation [UUM-136095].

Packages/com.unity.inputsystem/InputSystem/Runtime/Actions/InputActionRebindingExtensions.cs

@@ -321,7 +321,25 @@ public static string GetBindingDisplayString(this InputAction action, InputBindi
                 if (bindings[i].isPartOfComposite)
                     continue;
                 if (!bindingMask.Matches(bindings[i]))
-                    continue;
+                {
+                    // Composites are filtered atomically: any matching part promotes the whole
+                    // composite, consistent with how the index-based GetBindingDisplayString
+                    // overload below treats composites as one display unit; per-part filtering
+                    // would require a separate API.
+                    if (!bindings[i].isComposite)
+                        continue;
+                    var anyPartMatches = false;
+                    for (var partIndex = i + 1; partIndex < bindings.Count && bindings[partIndex].isPartOfComposite; ++partIndex)
+                    {
+                        if (bindingMask.Matches(bindings[partIndex]))
+                        {
+                            anyPartMatches = true;
+                            break;
+                        }
+                    }
+                    if (!anyPartMatches)
+                        continue;
+                }
 
                 ////REVIEW: should this filter out bindings that are not resolving to any controls?