Fix T86116: Failure to detect click events with modifier held

Click detection logic relied on the event queue not accumulating events
as newly added events at the end of the queue adjusted
`wm->eventstate->prev{val/type}` which was then compared with events
at the front of the queue.

This made Ctrl-Click fail to detect the click as releasing Ctrl
set the previous value before the previous event was handled.

In practice this only happened in heavy scenes,
updating 10 fps or lower. It also made automated tests fail that
accumulate events before handling them.

1 files changed, 14 insertions, 14 deletions

diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index 22fa3838ac3..205e49c5ab4 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -2960,16 +2960,16 @@ static int wm_handlers_do(bContext *C, wmEvent *event, ListBase *handlers)
     if (wm_action_not_handled(action)) {
       if (event->check_drag) {
         wmWindow *win = CTX_wm_window(C);
-        if (WM_event_drag_test(event, &win->eventstate->prevclickx)) {
+        if (WM_event_drag_test(event, &event->prevclickx)) {
           int x = event->x;
           int y = event->y;
           short val = event->val;
           short type = event->type;
 
-          event->x = win->eventstate->prevclickx;
-          event->y = win->eventstate->prevclicky;
+          event->x = event->prevclickx;
+          event->y = event->prevclicky;
           event->val = KM_CLICK_DRAG;
-          event->type = win->eventstate->type;
+          event->type = event->prevtype;
 
           CLOG_INFO(WM_LOG_HANDLERS, 1, "handling PRESS_DRAG");
 
@@ -3012,12 +3012,12 @@ static int wm_handlers_do(bContext *C, wmEvent *event, ListBase *handlers)
         }
       }
 
-      if (win && win->eventstate->prevtype == event->type) {
+      if (win && event->prevtype == event->type) {
 
         if (event->val == KM_RELEASE) {
-          if (win->eventstate->prevval == KM_PRESS) {
+          if (event->prevval == KM_PRESS) {
             if (win->eventstate->check_click == true) {
-              if (WM_event_drag_test(event, &win->eventstate->prevclickx)) {
+              if (WM_event_drag_test(event, &event->prevclickx)) {
                 win->eventstate->check_click = 0;
                 win->eventstate->check_drag = 0;
               }
@@ -3071,7 +3071,7 @@ static int wm_handlers_do(bContext *C, wmEvent *event, ListBase *handlers)
     else {
       wmWindow *win = CTX_wm_window(C);
       if (win) {
-        if (ISKEYMODIFIER(win->eventstate->type)) {
+        if (ISKEYMODIFIER(event->prevtype)) {
           win->eventstate->check_click = 0;
         }
       }
@@ -4358,15 +4358,15 @@ static wmWindow *wm_event_cursor_other_windows(wmWindowManager *wm, wmWindow *wi
   return NULL;
 }
 
-static bool wm_event_is_double_click(const wmEvent *event, const wmEvent *event_state)
+static bool wm_event_is_double_click(const wmEvent *event)
 {
-  if ((event->type == event_state->prevtype) && (event_state->prevval == KM_RELEASE) &&
+  if ((event->type == event->prevtype) && (event->prevval == KM_RELEASE) &&
       (event->val == KM_PRESS)) {
-    if (ISMOUSE(event->type) && WM_event_drag_test(event, &event_state->prevclickx)) {
+    if (ISMOUSE(event->type) && WM_event_drag_test(event, &event->prevclickx)) {
       /* Pass. */
     }
     else {
-      if ((PIL_check_seconds_timer() - event_state->prevclicktime) * 1000 < U.dbl_click_time) {
+      if ((PIL_check_seconds_timer() - event->prevclicktime) * 1000 < U.dbl_click_time) {
         return true;
       }
     }
@@ -4561,7 +4561,7 @@ void wm_event_add_ghostevent(wmWindowManager *wm, wmWindow *win, int type, void
       evt->type = event.type;
 
       /* Double click test. */
-      if (wm_event_is_double_click(&event, evt)) {
+      if (wm_event_is_double_click(&event)) {
         CLOG_INFO(WM_LOG_HANDLERS, 1, "Send double click");
         event.val = KM_DBL_CLICK;
       }
@@ -4699,7 +4699,7 @@ void wm_event_add_ghostevent(wmWindowManager *wm, wmWindow *win, int type, void
 
       /* Double click test. */
       /* If previous event was same type, and previous was release, and now it presses... */
-      if (wm_event_is_double_click(&event, evt)) {
+      if (wm_event_is_double_click(&event)) {
         CLOG_INFO(WM_LOG_HANDLERS, 1, "Send double click");
         event.val = KM_DBL_CLICK;
       }