From: Armin Ronacher <armin.ronacher@active-4.com>
Date: Thu, 5 Jan 2017 23:02:56 +0000 (+0100)
Subject: Optimize emitting of forced yields
X-Git-Tag: 2.9~30^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a4dde4b0650e28bbdd7b212f4e03a991dbaff919;p=thirdparty%2Fjinja.git

Optimize emitting of forced yields
---

diff --git a/jinja2/compiler.py b/jinja2/compiler.py
index 51116efe..f6c4638b 100644
--- a/jinja2/compiler.py
+++ b/jinja2/compiler.py
@@ -345,11 +345,9 @@ class CodeGenerator(NodeVisitor):
         """Visit a list of nodes as block in a frame.  If the current frame
         is no buffer a dummy ``if 0: yield None`` is written automatically.
         """
-        if frame.buffer is None:
-            self.writeline('if 0: yield None')
-        else:
-            self.writeline('pass')
         try:
+            if not nodes:
+                self.writeline('pass')
             for node in nodes:
                 self.visit(node, frame)
         except CompilerExit:
@@ -555,6 +553,7 @@ class CodeGenerator(NodeVisitor):
     def write_commons(self):
         self.writeline('resolve = context.resolve_or_missing')
         self.writeline('undefined = environment.undefined')
+        self.writeline('if 0: yield None')
 
     # -- Statement Visitors