From 99afe5fea7a0f76abfcb69a201435206d13aed9c Mon Sep 17 00:00:00 2001
From: Ben Cherry <bcherry@gmail.com>
Date: Thu, 4 Nov 2010 18:23:41 -0700
Subject: [PATCH] don't double render

---
 mustache.js           | 61 +++++++++++++++++++++++++++----------------
 test/mustache_spec.rb | 26 ++++++++++++++----
 2 files changed, 60 insertions(+), 27 deletions(-)

diff --git a/mustache.js b/mustache.js
index 35a8976..b2ebcba 100644
--- a/mustache.js
+++ b/mustache.js
@@ -35,12 +35,28 @@ var Mustache = function() {
       }
 
       template = this.render_pragmas(template);
+
       var html = this.render_section(template, context, partials);
-      if(in_recursion) {
-        return this.render_tags(html, context, partials, in_recursion);
-      }
 
-      this.render_tags(html, context, partials, in_recursion);
+      var stillNeedsToRender = (html === template);
+
+      if (stillNeedsToRender) {
+        if (in_recursion) {
+          return this.render_tags(html, context, partials, true);
+        }
+
+        this.render_tags(html, context, partials, false);
+      } else {
+        if(in_recursion) {
+          return html;
+        } else {
+          var lines = html.split("\n");
+          for (var i = 0; i < lines.length; i++) {
+            this.send(lines[i]);
+          }
+          return;
+        }
+      }
     },
 
     /*
@@ -66,7 +82,7 @@ var Mustache = function() {
             this.ctag);
       return template.replace(regex, function(match, pragma, options) {
         if(!that.pragmas_implemented[pragma]) {
-          throw({message: 
+          throw({message:
             "This implementation of mustache doesn't understand the '" +
             pragma + "' pragma"});
         }
@@ -103,39 +119,40 @@ var Mustache = function() {
       }
 
       var that = this;
-      // CSW - Added "+?" so it finds the tighest bound, not the widest
-      var regex = new RegExp(this.otag + "(\\^|\\#)\\s*(.+)\\s*" + this.ctag +
-              "\n*([\\s\\S]+?)" + this.otag + "\\/\\s*\\2\\s*" + this.ctag +
-              "\\s*", "mg");
+      var regex = new RegExp("(?:^([\\s\\S]*?))?" + this.otag + "(\\^|\\#)\\s*(.+)\\s*" + this.ctag +
+                    "\n*([\\s\\S]+?)" + this.otag + "\\/\\s*\\3\\s*" + this.ctag + "\\s*" +
+                    "([\\s\\S]*?)(?=(?:" + this.otag + "(?:\\^|\\#)\\s*(?:.+)\\s*" + this.ctag + ")|$)", "mg");
 
       // for each {{#foo}}{{/foo}} section do...
-      return template.replace(regex, function(match, type, name, content) {
+      return template.replace(regex, function(match, before, type, name, content, after) {
+        var renderedBefore = before ? that.render_tags(before, context, partials, true) : "",
+            renderedAfter = after ? that.render_tags(after, context, partials, true) : "";
+
         var value = that.find(name, context);
         if(type == "^") { // inverted section
           if(!value || that.is_array(value) && value.length === 0) {
             // false or empty list, render it
-            return that.render(content, context, partials, true);
+            return renderedBefore + that.render(content, context, partials, true) + renderedAfter;
           } else {
-            return "";
+            return renderedBefore + "" + renderedAfter;
           }
         } else if(type == "#") { // normal section
           if(that.is_array(value)) { // Enumerable, Let's loop!
-            return that.map(value, function(row) {
-              return that.render(content, that.create_context(row),
-                partials, true);
-            }).join("");
+            return renderedBefore + that.map(value, function(row) {
+              return that.render(content, that.create_context(row), partials, true);
+            }).join("") + renderedAfter;
           } else if(that.is_object(value)) { // Object, Use it as subcontext!
-            return that.render(content, that.create_context(value),
-              partials, true);
+            return renderedBefore + that.render(content, that.create_context(value),
+              partials, true) + renderedAfter;
           } else if(typeof value === "function") {
             // higher order section
-            return value.call(context, content, function(text) {
+            return renderedBefore + value.call(context, content, function(text) {
               return that.render(text, context, partials, true);
-            });
+            }) + renderedAfter;
           } else if(value) { // boolean section
-            return that.render(content, context, partials, true);
+            return renderedBefore + that.render(content, context, partials, true) + renderedAfter;
           } else {
-            return "";
+            return renderedBefore + "" + renderedAfter;
           }
         }
       });
diff --git a/test/mustache_spec.rb b/test/mustache_spec.rb
index 9ede6c8..c4900a9 100644
--- a/test/mustache_spec.rb
+++ b/test/mustache_spec.rb
@@ -49,13 +49,29 @@ describe "mustache" do
     JS
     run_js(js).should == "\n"
   end
-  
+
+  it "should not double-render" do
+    js = <<-JS
+      #{@mustache}
+      var template = "{{#foo}}{{bar}}{{/foo}}";
+      var ctx = {
+        foo: true,
+        bar: "{{win}}",
+        win: "FAIL"
+      };
+
+      print(Mustache.to_html(template, ctx))
+    JS
+
+    run_js(js).strip.should == "{{win}}"
+  end
+
   non_partials.each do |testname|
-    describe testname do 
+    describe testname do
       it "should generate the correct html" do
 
         view, template, expect = load_test(__DIR__, testname)
-        
+
         runner = <<-JS
           try {
             #{@mustache}
@@ -101,7 +117,7 @@ describe "mustache" do
     describe testname do
       it "should generate the correct html" do
 
-        view, template, partial, expect = 
+        view, template, partial, expect =
               load_test(__DIR__, testname, true)
 
         runner = <<-JS
@@ -116,7 +132,7 @@ describe "mustache" do
             print('ERROR: ' + e.message);
           }
         JS
-      
+
         run_js(runner).should == expect
       end
       it "should sendFun the correct html" do