Scrollbar: fixed a codepath leading to a divide-by-zero. (#9089)

docs/CHANGELOG.txt

@@ -43,6 +43,9 @@ Breaking Changes:
 
 Other Changes:
 
+- Scrollbar: fixed a codepath leading to a divide-by-zero (which would not be
+  noticeable by user but detected by sanitizers). (#9089) [@judicaelclair]
+
 
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  VERSION 1.92.5 (Released 2025-11-20)

imgui_widgets.cpp

@@ -1037,6 +1037,8 @@ bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, ImS6
 
     // V denote the main, longer axis of the scrollbar (= height for a vertical scrollbar)
     const float scrollbar_size_v = (axis == ImGuiAxis_X) ? bb.GetWidth() : bb.GetHeight();
+    if (scrollbar_size_v < 1.0f)
+        return false;
 
     // Calculate the height of our grabbable box. It generally represent the amount visible (vs the total scrollable amount)
     // But we maintain a minimum size in pixel to allow for the user to still aim inside.