Make discriminator read-only by default

Fixes #21154
dotnet · Jul 29, 2020 · f3f7551 · f3f7551
1 parent ea25000
commit f3f7551
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Showing 5 changed files with 763 additions and 68 deletions.
diff --git a/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs b/src/EFCore.Relational/Migrations/Internal/MigrationsModelDiffer.cs
@@ -1922,15 +1922,17 @@ protected virtual Dictionary<IEntityType, List<ITable>> DiffData(
                             var targetColumn = targetProperty.GetTableColumnMappings()
                                 .FirstOrDefault(m => m.TableMapping.EntityType == entry.EntityType && m.TableMapping.Table == targetTable)?.Column;
                             var sourceColumn = diffContext.FindSource(targetColumn);
-                            if (sourceColumn == null)
-                            {
-                                continue;
-                            }
-
-                            var sourceProperty = sourceColumn.PropertyMappings.Select(m => m.Property)
+                            var sourceProperty = sourceColumn?.PropertyMappings.Select(m => m.Property)
                                 .FirstOrDefault(p => p.DeclaringEntityType.IsAssignableFrom(sourceEntityType));
                             if (sourceProperty == null)
                             {
+                                if (targetProperty.GetAfterSaveBehavior() != PropertySaveBehavior.Save
+                                    && (targetProperty.ValueGenerated & ValueGenerated.OnUpdate) == 0)
+                                {
+                                    entryMapping.RecreateRow = true;
+                                    break;
+                                }
+
                                 continue;
                             }
 

diff --git a/src/EFCore/Metadata/Internal/InternalEntityTypeBuilder.cs b/src/EFCore/Metadata/Internal/InternalEntityTypeBuilder.cs
@@ -4112,7 +4112,8 @@ private InternalPropertyBuilder GetOrCreateDiscriminatorProperty(Type type, stri
                 type ?? discriminatorProperty?.ClrType ?? _defaultDiscriminatorType,
                 name ?? discriminatorProperty?.Name ?? _defaultDiscriminatorName,
                 typeConfigurationSource: type != null ? configurationSource : (ConfigurationSource?)null,
-                configurationSource: configurationSource);
+                configurationSource)
+                ?.AfterSave(PropertySaveBehavior.Throw, ConfigurationSource.Convention);
         }
 
         private DiscriminatorBuilder DiscriminatorBuilder(