Only remove comments before the first statement

2 files changed, 12 insertions, 7 deletions

diff --git a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
index 83b82506d3..f1af90c1e8 100644
--- a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
@@ -5,6 +5,7 @@ module ActiveRecord
     class PostgreSQLDatabaseTasks # :nodoc:
       DEFAULT_ENCODING = ENV["CHARSET"] || "utf8"
       ON_ERROR_STOP_1 = "ON_ERROR_STOP=1".freeze
+      SQL_COMMENT_BEGIN = "--".freeze
 
       delegate :connection, :establish_connection, :clear_active_connections!,
         to: ActiveRecord::Base
@@ -67,7 +68,7 @@ module ActiveRecord
         end
         args << configuration["database"]
         run_cmd("pg_dump", args, "dumping")
-        remove_sql_comments(filename)
+        remove_sql_header_comments(filename)
         File.open(filename, "a") { |f| f << "SET search_path TO #{connection.schema_search_path};\n\n" }
       end
 
@@ -114,11 +115,15 @@ module ActiveRecord
           msg
         end
 
-        def remove_sql_comments(filename)
-          tempfile = Tempfile.open('uncommented_structure.sql')
+        def remove_sql_header_comments(filename)
+          removing_comments = true
+          tempfile = Tempfile.open("uncommented_structure.sql")
           begin
             File.foreach(filename) do |line|
-              tempfile << line unless line.start_with?('--')
+              unless removing_comments && (line.start_with?(SQL_COMMENT_BEGIN) || line.blank?)
+                tempfile << line
+                removing_comments = false
+              end
             end
           ensure
             tempfile.close
diff --git a/activerecord/test/cases/tasks/postgresql_rake_test.rb b/activerecord/test/cases/tasks/postgresql_rake_test.rb
index a28217c2e6..512388af6b 100644
--- a/activerecord/test/cases/tasks/postgresql_rake_test.rb
+++ b/activerecord/test/cases/tasks/postgresql_rake_test.rb
@@ -240,13 +240,13 @@ if current_adapter?(:PostgreSQLAdapter)
         ActiveRecord::Tasks::DatabaseTasks.structure_dump(@configuration, @filename)
       end
 
-      def test_structure_dump_comments_removed
+      def test_structure_dump_header_comments_removed
         Kernel.stubs(:system).returns(true)
-        File.write(@filename, "-- comment\n not comment\n")
+        File.write(@filename, "-- header comment\n\n-- more header comment\n statement \n-- lower comment\n")
 
         ActiveRecord::Tasks::DatabaseTasks.structure_dump(@configuration, @filename)
 
-        assert_equal " not comment\n", File.readlines(@filename).first
+        assert_equal [" statement \n", "-- lower comment\n"], File.readlines(@filename).first(2)
       end
 
       def test_structure_dump_with_extra_flags