Optimize compile-element ::literal-tag to emit the element content …

…only once

src/hiccup/compiler.clj

@@ -335,21 +335,22 @@
   (let [[tag tag-attrs _] (normalize-element-form [tag])
         attrs-sym (gensym "attrs")]
     `(let [~attrs-sym ~attrs]
-       (if (map? ~attrs-sym)
-         ~(if (container-tag? tag content)
-            `(build-string ~(str "<" tag)
-                           (render-attr-map (merge ~tag-attrs ~attrs-sym)) ">"
-                           ;; tail
-                           ~@(compile-seq content)
-                           ~(str "</" tag ">"))
-            `(build-string ~(str "<" tag)
-                           (render-attr-map (merge ~tag-attrs ~attrs-sym))
-                           ~(end-tag)))
-         (build-string ~(str "<" tag (render-attr-map tag-attrs) ">")
-                       ~@(compile-seq [attrs-sym])
-                       ;; tail
-                       ~@(compile-seq content)
-                       ~(str "</" tag ">"))))))
+       (build-string
+         (if (map? ~attrs-sym)
+           ~(if (container-tag? tag content)
+              `(build-string ~(str "<" tag)
+                             (render-attr-map (merge ~tag-attrs ~attrs-sym))
+                             ">")
+              `(build-string ~(str "<" tag)
+                             (render-attr-map (merge ~tag-attrs ~attrs-sym))
+                             ~(end-tag)))
+           (build-string ~(str "<" tag (render-attr-map tag-attrs) ">")
+                         ~@(compile-seq [attrs-sym])))
+         ;; content and ending tag (when the above code did not emit an ending tag)
+         (when (or ~(boolean (container-tag? tag content))
+                   (not (map? ~attrs-sym)))
+           (build-string ~@(compile-seq content)
+                         ~(str "</" tag ">")))))))
 
 (defmethod compile-element :default
   [element]