Merge pull request rails#6418 from pwnall/pgsql_bytea_limit3

Postgresql doesn't accept limits on binary (bytea) columns (for 3-2-stable)

Author: tenderlove

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -1067,14 +1067,25 @@ def index_name_length
 
       # Maps logical Rails types to PostgreSQL-specific data types.
       def type_to_sql(type, limit = nil, precision = nil, scale = nil)
-        return super unless type.to_s == 'integer'
-        return 'integer' unless limit
-
-        case limit
-          when 1, 2; 'smallint'
-          when 3, 4; 'integer'
-          when 5..8; 'bigint'
-          else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.")
+        case type.to_s
+        when 'binary'
+          # PostgreSQL doesn't support limits on binary (bytea) columns.
+          # The hard limit is 1Gb, because of a 32-bit size field, and TOAST.
+          case limit
+          when nil, 0..0x3fffffff; super(type)
+          else raise(ActiveRecordError, "No binary type has byte size #{limit}.")
+          end
+        when 'integer'
+          return 'integer' unless limit
+  
+          case limit
+            when 1, 2; 'smallint'
+            when 3, 4; 'integer'
+            when 5..8; 'bigint'
+            else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.")
+          end
+        else
+          super
         end
       end
 

activerecord/test/schema/schema.rb

@@ -75,6 +75,7 @@ def create_table(*args, &block)
   create_table :binaries, :force => true do |t|
     t.string :name
     t.binary :data
+    t.binary :short_data, :limit => 2048
   end
 
   create_table :birds, :force => true do |t|