Nav, Inputs: fixed a crash that could occur when opening a popup following the processing of a global shortcut while no windows were focused.

Regression test: "window_popup_from_shortcut"

docs/CHANGELOG.txt

@@ -54,6 +54,8 @@ Other Changes:
   e.g. using clipper with ItemsHeight=1 in order to clip in pixel units. (#8886)
 - Nav: fixed Ctrl+Tab window appearing as empty when the sole active and focused
   window has the ImGuiWindowFlags_NoNavFocus flag. (#8914)
+- Nav: fixed a crash that could occur when opening a popup following the processing
+  of a global shortcut while no windows were focused.
 - Bullet: fixed tesselation amount which looked out of place in very large sizes.
 - InputText: added ImGuiInputTextFlags_WordWrap flag to word-wrap multi-line buffers.
   (#3237, #952, #1062, #7363). Current caveats:

imgui.cpp

@@ -13413,6 +13413,9 @@ static ImVec2 ImGui::NavCalcPreferredRefPos()
 
     const bool activated_shortcut = g.ActiveId != 0 && g.ActiveIdFromShortcut && g.ActiveId == g.LastItemData.ID;
 
+    if (source != ImGuiInputSource_Mouse && !activated_shortcut && window == NULL)
+        source = ImGuiInputSource_Mouse;
+
     // Testing for !activated_shortcut here could in theory be removed if we decided that activating a remote shortcut altered one of the g.NavDisableXXX flag.
     if (source == ImGuiInputSource_Mouse)
     {
@@ -13432,7 +13435,7 @@ static ImVec2 ImGui::NavCalcPreferredRefPos()
             ref_rect = WindowRectRelToAbs(window, window->NavRectRel[g.NavLayer]);
 
         // Take account of upcoming scrolling (maybe set mouse pos should be done in EndFrame?)
-        if (window->LastFrameActive != g.FrameCount && (window->ScrollTarget.x != FLT_MAX || window->ScrollTarget.y != FLT_MAX))
+        if (window != NULL && window->LastFrameActive != g.FrameCount && (window->ScrollTarget.x != FLT_MAX || window->ScrollTarget.y != FLT_MAX))
         {
             ImVec2 next_scroll = CalcNextScrollFromScrollTargetAndClamp(window);
             ref_rect.Translate(window->Scroll - next_scroll);