Clipper, Nav: fixed an UBSan warning when using in a ListClipper region . (#9160)

diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 7e3e4ae..253a4b0 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt

@@ -179,6 +179,7 @@
     used io.DisplayFramebufferScale (very old code), effectively making those
     actions faster on macOS/iOS retina screens.
     (changed this to use a style scale factor that's not fully formalized yet)
+  - Fixed an UBSan warning when using in a ListClipper region . (#9160)
 - Scrollbar: fixed a codepath leading to a divide-by-zero (which would not be
   noticeable by user but detected by sanitizers). (#9089) [@judicaelclair]
 - InvisibleButton: allow calling with size (0,0) to fit to available content 

diff --git a/imgui.cpp b/imgui.cpp
index 82f38ee..7998369 100644
--- a/imgui.cpp
+++ b/imgui.cpp

@@ -3399,7 +3399,8 @@
             if (is_nav_request)
             {
                 data->Ranges.push_back(ImGuiListClipperRange::FromPositions(g.NavScoringRect.Min.y, g.NavScoringRect.Max.y, nav_off_min, nav_off_max));
-                data->Ranges.push_back(ImGuiListClipperRange::FromPositions(g.NavScoringNoClipRect.Min.y, g.NavScoringNoClipRect.Max.y, nav_off_min, nav_off_max));
+                if (!g.NavScoringNoClipRect.IsInverted())
+                    data->Ranges.push_back(ImGuiListClipperRange::FromPositions(g.NavScoringNoClipRect.Min.y, g.NavScoringNoClipRect.Max.y, nav_off_min, nav_off_max));
             }
             if (is_nav_request && (g.NavMoveFlags & ImGuiNavMoveFlags_IsTabbing) && g.NavTabbingDir == -1)
                 data->Ranges.push_back(ImGuiListClipperRange::FromIndices(clipper->ItemsCount - 1, clipper->ItemsCount));

diff --git a/imgui_internal.h b/imgui_internal.h
index e9e644f..50691e1 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h

@@ -2352,7 +2352,7 @@
     ImGuiDir                NavMoveDirForDebug;
     ImGuiDir                NavMoveClipDir;                     // FIXME-NAV: Describe the purpose of this better. Might want to rename?
     ImRect                  NavScoringRect;                     // Rectangle used for scoring, in screen space. Based of window->NavRectRel[], modified for directional navigation scoring.
-    ImRect                  NavScoringNoClipRect;               // Some nav operations (such as PageUp/PageDown) enforce a region which clipper will attempt to always keep submitted
+    ImRect                  NavScoringNoClipRect;               // Some nav operations (such as PageUp/PageDown) enforce a region which clipper will attempt to always keep submitted. Unset/invalid if inverted.
     int                     NavScoringDebugCount;               // Metrics for debugging
     int                     NavTabbingDir;                      // Generally -1 or +1, 0 when tabbing without a nav id
     int                     NavTabbingCounter;                  // >0 when counting items for tabbing