Merge rules within combined @layer blocks

Author: devongovett

src/lib.rs

@@ -6481,7 +6481,7 @@ mod tests {
         }
       }
       @layer foo {
-        .bar {
+        .foo {
           background: #fff;
         }
 
@@ -6494,9 +6494,6 @@ mod tests {
       @layer foo {
         .foo {
           color: red;
-        }
-
-        .bar {
           background: #fff;
         }
 

src/rules/mod.rs

@@ -305,11 +305,13 @@ impl<'i> CssRuleList<'i> {
           if let Some(CssRule::LayerBlock(last_style_rule)) = rules.last_mut() {
             if last_style_rule.name == layer.name {
               last_style_rule.rules.0.extend(layer.rules.0.drain(..));
-            }
-            if layer.minify(context, parent_is_unused)? {
+              last_style_rule.minify(context, parent_is_unused)?;
               continue;
             }
           }
+          if layer.minify(context, parent_is_unused)? {
+            continue;
+          }
         }
         CssRule::MozDocument(document) => document.minify(context)?,
         CssRule::Style(style) => {