Include template name with line numbers in render errors.

lib/liquid/context.rb

@@ -13,7 +13,7 @@ module Liquid
   #   context['bob']  #=> nil  class Context
   class Context
     attr_reader :scopes, :errors, :registers, :environments, :resource_limits
-    attr_accessor :exception_handler, :render_errors
+    attr_accessor :exception_handler, :render_errors, :template_name
 
     def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, render_errors = true)
       @environments     = [environments].flatten
@@ -65,6 +65,7 @@ module Liquid
 
     def handle_error(e, token = nil)
       if e.is_a?(Liquid::Error)
+        e.template_name = template_name
         e.set_line_number_from_token(token)
       end
 

lib/liquid/errors.rb

@@ -1,6 +1,7 @@
 module Liquid
   class Error < ::StandardError
     attr_accessor :line_number
+    attr_accessor :template_name
     attr_accessor :markup_context
 
     def to_s(with_prefix = true)
@@ -41,7 +42,9 @@ module Liquid
       end
 
       if line_number
-        str << " (line #{line_number})"
+        str << " ("
+        str << template_name << " " if template_name
+        str << "line " << line_number.to_s << ")"
       end
 
       str << ": "

lib/liquid/tags/include.rb

@@ -41,9 +41,9 @@ module Liquid
     end
 
     def render(context)
-      partial = load_cached_partial(context)
-
       template_name = context.evaluate(@template_name_expr)
+      partial = load_cached_partial(template_name, context)
+
       context_variable_name = template_name.split('/'.freeze).last
 
       variable = if @variable_name_expr
@@ -52,28 +52,33 @@ module Liquid
         context.find_variable(template_name)
       end
 
-      context.stack do
-        @attributes.each do |key, value|
-          context[key] = context.evaluate(value)
-        end
+      old_template_name = context.template_name
+      begin
+        context.template_name = template_name
+        context.stack do
+          @attributes.each do |key, value|
+            context[key] = context.evaluate(value)
+          end
 
-        if variable.is_a?(Array)
-          variable.collect do |var|
-            context[context_variable_name] = var
+          if variable.is_a?(Array)
+            variable.collect do |var|
+              context[context_variable_name] = var
+              partial.render(context)
+            end
+          else
+            context[context_variable_name] = variable
             partial.render(context)
           end
-        else
-          context[context_variable_name] = variable
-          partial.render(context)
         end
+      ensure
+        context.template_name = old_template_name
       end
     end
 
     private
 
-    def load_cached_partial(context)
+    def load_cached_partial(template_name, context)
       cached_partials = context.registers[:cached_partials] || {}
-      template_name = context.evaluate(@template_name_expr)
 
       if cached = cached_partials[template_name]
         return cached