Fix for 15256 - bad generated SQL for DefaultValueSql with line breaks.

Author: lajones

src/EFCore.Relational/Migrations/MigrationsSqlGenerator.cs

@@ -1239,7 +1239,7 @@ protected virtual void DefaultValue(
             {
                 builder
                     .Append(" DEFAULT (")
-                    .Append(defaultValueSql)
+                    .Append(EscapeLineBreaks(defaultValueSql))
                     .Append(")");
             }
             else if (defaultValue != null)
@@ -1676,5 +1676,21 @@ protected virtual bool TryGetVersion([CanBeNull] IModel model, out string versio
 
             return true;
         }
+
+        private static readonly char[] LineBreakChars = new char[] { '\r', '\n' };
+        private static string EscapeLineBreaks(string value)
+        {
+            if (value == null
+                || value.IndexOfAny(LineBreakChars) == -1)
+            {
+                return value;
+            }
+
+            return ("CONCAT('" + value
+                .Replace("\r", "', CHAR(13), '")
+                .Replace("\n", "', CHAR(10), '") + "')")
+                .Replace("'', ", string.Empty)
+                .Replace(", ''", string.Empty);
+        }
     }
 }

test/EFCore.Relational.Tests/Migrations/MigrationSqlGeneratorTestBase.cs

@@ -138,6 +138,26 @@ public virtual void SqlOperation()
             => Generate(
                 new SqlOperation { Sql = "-- I <3 DDL" });
 
+        public virtual void DefaultValueSql_with_line_breaks()
+        {
+            Generate(
+                new CreateTableOperation
+                {
+                    Name = "TestLineBreaks",
+                    Schema = "dbo",
+                    Columns =
+                    {
+                        new AddColumnOperation
+                        {
+                            Name = "TestDefaultValueSql",
+                            Table = "Test",
+                            ClrType = typeof(string),
+                            DefaultValueSql = "\r\nVarious Line\rBreaks\n"
+                        }
+                    }
+                });
+        }
+
         protected TestHelpers TestHelpers { get; }
 
         protected MigrationSqlGeneratorTestBase(TestHelpers testHelpers)

test/EFCore.SqlServer.Tests/Migrations/SqlServerMigrationSqlGeneratorTest.cs

@@ -545,6 +545,17 @@ public virtual void SqlOperation_ignores_non_go()
 ");
         }
 
+        [ConditionalFact]
+        public override void DefaultValueSql_with_line_breaks()
+        {
+            base.DefaultValueSql_with_line_breaks();
+
+            AssertSql(@"CREATE TABLE [dbo].[TestLineBreaks] (
+    [TestDefaultValueSql] nvarchar(max) NOT NULL DEFAULT (CONCAT(CHAR(13), CHAR(10), 'Various Line', CHAR(13), 'Breaks', CHAR(10)))
+);
+");
+        }
+
         public SqlServerMigrationSqlGeneratorTest()
             : base(SqlServerTestHelpers.Instance)
         {

test/EFCore.Sqlite.Tests/Migrations/SqliteMigrationSqlGeneratorTest.cs

@@ -71,6 +71,18 @@ public virtual void DefaultValue_formats_literal_correctly()
 ");
         }
 
+        [ConditionalFact]
+        public override void DefaultValueSql_with_line_breaks()
+        {
+            base.DefaultValueSql_with_line_breaks();
+
+            AssertSql(
+                @"CREATE TABLE ""TestLineBreaks"" (
+    ""TestDefaultValueSql"" TEXT NOT NULL DEFAULT (CONCAT(CHAR(13), CHAR(10), 'Various Line', CHAR(13), 'Breaks', CHAR(10)))
+);
+");
+        }
+
         [ConditionalTheory]
         [InlineData(true, null)]
         [InlineData(false, "PK_Id")]