Ensure blocks do not clobber eex buffer

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>

Author: José Valim

lib/eex/lib/eex/engine.ex

@@ -98,16 +98,16 @@ defmodule EEx.Engine do
   """
   def handle_expr(buffer, "=", expr) do
     quote do
-      tmp = unquote(buffer)
-      tmp <> String.Chars.to_string(unquote(expr))
+      tmp1 = unquote(buffer)
+      tmp1 <> String.Chars.to_string(unquote(expr))
     end
   end
 
   def handle_expr(buffer, "", expr) do
     quote do
-      tmp = unquote(buffer)
+      tmp2 = unquote(buffer)
       unquote(expr)
-      tmp
+      tmp2
     end
   end
 end

lib/eex/test/eex_test.exs

@@ -252,7 +252,7 @@ Number <%= x %>
     assert_eval expected, string
   end
 
-  test "do not consider already finished functions" do
+  test "properly handle functions on the left side of clauses" do
     expected = """
 foo
 
@@ -287,6 +287,18 @@ foo
     assert_eval "\n\n  Good\n \n", string
   end
 
+  test "evaluates expressions with buffers" do
+    string = """
+    <%= 123 %>
+    <% if true do %>
+      <%= 456 %>
+    <% end %>
+    <%= 789 %>
+    """
+
+    assert_eval "123\n\n789\n", string
+  end
+
   test "for comprehensions" do
     string = """
     <%= for _name <- packages || [] do %>