Event: Make trigger(focus/blur/click) work with native handlers

In `leverageNative`, instead of calling `event.stopImmediatePropagation()`
which would abort both native & jQuery handlers, set the wrapper's
`isImmediatePropagationStopped` property to a function returning `true`.
Since for each element + type pair jQuery attaches only one native handler,
there is also only one wrapper jQuery event so this achieves the goal:
on the target element jQuery handlers don't fire but native ones do.

Unfortunately, this workaround doesn't work for handlers on ancestors
- since the native event is re-wrapped by a jQuery one on each level of
the propagation, the only way to stop it for jQuery was to stop it for
everyone via native `stopPropagation()`. This is not a problem for
`focus`/`blur` which don't bubble, but it does also stop `click` on
checkboxes and radios. We accept this limitation.

Fixes gh-5015
Closes gh-5228

1 files changed, 12 insertions, 4 deletions

diff --git a/src/event.js b/src/event.js
index 95221f475..c9a397c90 100644
--- a/src/event.js
+++ b/src/event.js
@@ -545,8 +545,8 @@ function leverageNative( el, type, isSetup ) {
 					}
 
 				// If this is an inner synthetic event for an event with a bubbling surrogate
-				// (focus or blur), assume that the surrogate already propagated from triggering the
-				// native event and prevent that from happening again here.
+				// (focus or blur), assume that the surrogate already propagated from triggering
+				// the native event and prevent that from happening again here.
 				// This technically gets the ordering wrong w.r.t. to `.trigger()` (in which the
 				// bubbling surrogate propagates *after* the non-bubbling base), but that seems
 				// less bad than duplication.
@@ -565,8 +565,16 @@ function leverageNative( el, type, isSetup ) {
 					this
 				) );
 
-				// Abort handling of the native event
-				event.stopImmediatePropagation();
+				// Abort handling of the native event by all jQuery handlers while allowing
+				// native handlers on the same element to run. On target, this is achieved
+				// by stopping immediate propagation just on the jQuery event. However,
+				// the native event is re-wrapped by a jQuery one on each level of the
+				// propagation so the only way to stop it for jQuery is to stop it for
+				// everyone via native `stopPropagation()`. This is not a problem for
+				// focus/blur which don't bubble, but it does also stop click on checkboxes
+				// and radios. We accept this limitation.
+				event.stopPropagation();
+				event.isImmediatePropagationStopped = returnTrue;
 			}
 		}
 	} );