find gracefully copes with blank :conditions. Closes #7599.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6852 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 18 insertions, 3 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 5a2318ef1e..9bf09e97c1 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* find gracefully copes with blank :conditions.  #7599 [Dan Manges, johnnyb]
+
 * validates_numericality_of takes :greater_than, :greater_than_or_equal_to, :equal_to, :less_than, :less_than_or_equal_to, :odd, and :even options.  #3952 [Bob Silva, Dan Kubb, Josh Peek]
 
 * MySQL: create_database takes :charset and :collation options. Charset defaults to utf8.  #8448 [matt]
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 81b492e65e..3ba1cb26d1 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1249,11 +1249,11 @@ module ActiveRecord #:nodoc:
         def add_conditions!(sql, conditions, scope = :auto)
           scope = scope(:find) if :auto == scope
           segments = []
-          segments << sanitize_sql(scope[:conditions]) if scope && scope[:conditions]
-          segments << sanitize_sql(conditions) unless conditions.nil?
+          segments << sanitize_sql(scope[:conditions]) if scope && !scope[:conditions].blank?
+          segments << sanitize_sql(conditions) unless conditions.blank?
           segments << type_condition unless descends_from_active_record?
           segments.compact!
-          sql << "WHERE (#{segments.join(") AND (")}) " unless segments.empty?
+          sql << "WHERE (#{segments.join(") AND (")}) " unless segments.all?(&:blank?)
         end
 
         def type_condition
diff --git a/activerecord/test/finder_test.rb b/activerecord/test/finder_test.rb
index 1c4b9d4777..de7d1b4318 100644
--- a/activerecord/test/finder_test.rb
+++ b/activerecord/test/finder_test.rb
@@ -1,4 +1,5 @@
 require 'abstract_unit'
+require 'fixtures/comment'
 require 'fixtures/company'
 require 'fixtures/topic'
 require 'fixtures/reply'
@@ -128,6 +129,18 @@ class FinderTest < Test::Unit::TestCase
     assert topic.attribute_present?("author_name")
     assert topic.respond_to?("author_name")
   end
+  
+  def test_find_on_blank_conditions
+    [nil, " ", [], {}].each do |blank|
+      assert_nothing_raised { Topic.find(:first, :conditions => blank) }
+    end
+  end
+  
+  def test_find_on_blank_bind_conditions
+    [ [""], ["",{}] ].each do |blank|
+      assert_nothing_raised { Topic.find(:first, :conditions => blank) }
+    end
+  end
 
   def test_find_on_array_conditions
     assert Topic.find(1, :conditions => ["approved = ?", false])