Make the mysql schema dumper roundtrip the limits of text/blob columns. Closes #7424 [will.bryant]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8969 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 40 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index c37bfd3e81..6432c3cfee 100755
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -112,6 +112,23 @@ module ActiveRecord
           super
         end
 
+        def extract_limit(sql_type)
+          if sql_type =~ /blob|text/i
+            case sql_type
+            when /tiny/i
+              255
+            when /medium/i
+              16777215
+            when /long/i
+              2147483647 # mysql only allows 2^31-1, not 2^32-1, somewhat inconsistently with the tiny/medium/normal cases
+            else
+              super # we could return 65535 here, but we leave it undecorated by default
+            end
+          else
+            super
+          end
+        end
+
         # MySQL misreports NOT NULL column default when none is given.
         # We can't detect this for columns which may have a legitimate ''
         # default (string) but we can for others (integer, datetime, boolean,
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 8413fce3fa..d96bd62e56 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -115,6 +115,18 @@ if ActiveRecord::Base.connection.respond_to?(:tables)
         assert_not_nil(match, "nonstandardpk table not found")
         assert_match %r(:primary_key => "movieid"), match[1], "non-standard primary key not preserved"
       end
+
+      def test_schema_dump_includes_length_for_mysql_blob_and_text_fields
+        output = standard_dump
+        assert_match %r{t.binary\s+"tiny_blob",\s+:limit => 255$}, output
+        assert_match %r{t.binary\s+"normal_blob"$}, output
+        assert_match %r{t.binary\s+"medium_blob",\s+:limit => 16777215$}, output
+        assert_match %r{t.binary\s+"long_blob",\s+:limit => 2147483647$}, output
+        assert_match %r{t.text\s+"tiny_text",\s+:limit => 255$}, output
+        assert_match %r{t.text\s+"normal_text"$}, output
+        assert_match %r{t.text\s+"medium_text",\s+:limit => 16777215$}, output
+        assert_match %r{t.text\s+"long_text",\s+:limit => 2147483647$}, output
+      end
     end
 
     def test_schema_dump_includes_decimal_options
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 45da902088..33aa6e2ea4 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -25,6 +25,17 @@ ActiveRecord::Schema.define do
       t.binary :data
     end
 
+    create_table :binary_fields, :force => true do |t|
+      t.binary :tiny_blob,   :limit => 255
+      t.binary :normal_blob, :limit => 65535
+      t.binary :medium_blob, :limit => 16777215
+      t.binary :long_blob,   :limit => 2147483647
+      t.text   :tiny_text,   :limit => 255
+      t.text   :normal_text, :limit => 65535
+      t.text   :medium_text, :limit => 16777215
+      t.text   :long_text,   :limit => 2147483647
+    end
+
     create_table :booleantests, :force => true do |t|
       t.integer :value
     end