Bug 1727289 - null-check root pres context to avoid crashes on automa…

…tion in some cases. MANUAL PUSH: Trivial orange fix CLOSED TREE
dothq · Aug 30, 2021 · c859adb · c859adb
1 parent 38d10db
commit c859adb
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/widget/nsNativeBasicTheme.cpp b/widget/nsNativeBasicTheme.cpp
@@ -342,8 +342,10 @@ static std::pair<sRGBColor, sRGBColor> SystemColorPair(
 /* static */
 auto nsNativeBasicTheme::GetDPIRatioForScrollbarPart(nsPresContext* aPc)
     -> DPIRatio {
-  if (auto* widget = aPc->GetRootPresContext()->GetRootWidget()) {
-    return widget->GetDefaultScale();
+  if (auto* rootPc = aPc->GetRootPresContext()) {
+    if (auto* widget = rootPc->GetRootWidget()) {
+      return widget->GetDefaultScale();
+    }
   }
   return DPIRatio(float(AppUnitsPerCSSPixel()) /
                   aPc->DeviceContext()->AppUnitsPerDevPixelAtUnitFullZoom());