🐛 Fix problem with shadow negative spread

CHANGES.md

@@ -125,6 +125,7 @@
 - [VIEWER] Cannot scroll down in code </> mode [Taiga #4655](https://tree.taiga.io/project/penpot/issue/4655)
 - Strange cursor behavior after clicking viewport with text tool [Taiga #4363](https://tree.taiga.io/project/penpot/issue/4363)
 - Selected color affects all of them [Taiga #5285](https://tree.taiga.io/project/penpot/issue/5285)
+- Fix problem with shadow negative spread [Github #3421](https://github.com/penpot/penpot/issues/3421)
 
 
 ## 1.19.5

frontend/src/app/main/ui/shapes/filters.cljs

@@ -45,6 +45,12 @@
                        :in "SourceAlpha"
                        :result filter-id}])
 
+     (when (< spread 0)
+       [:feMorphology {:radius (- spread)
+                       :operator "erode"
+                       :in "SourceAlpha"
+                       :result filter-id}])
+
      [:feOffset {:dx offset-x :dy offset-y}]
      [:feGaussianBlur {:stdDeviation (/ blur 2)}]
      [:& color-matrix {:color color}]