Fix default size if not provided

packages/mermaid/src/rendering-util/rendering-elements/shapes/stateStart.ts

@@ -12,6 +12,28 @@ export const stateStart = (
 ) => {
   const { lineColor } = themeVariables;
 
+  // If incoming height & width are present, subtract the padding from them
+  // as labelHelper does not take padding into account
+  // also check if the width or height is less than minimum default values (50),
+  // if so set it to min value
+  if (node.width || node.height) {
+    if ((node.width ?? 0) < 50) {
+      node.width = 50;
+    }
+
+    if ((node.height ?? 0) < 50) {
+      node.height = 50;
+    }
+  }
+
+  if (!node.width) {
+    node.width = 50;
+  }
+
+  if (!node.height) {
+    node.width = 50;
+  }
+
   const shapeSvg = parent
     .insert('g')
     .attr('class', 'node default')