Fixed collection bug with reoder section.

Author: ivanvorobei

SPDiffable.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name = 'SPDiffable'
-  s.version = '4.0.6'
+  s.version = '4.0.7'
   s.summary = 'Extension of Diffable API which allow not duplicate code and use less models. Included example for SideBar.'
   s.homepage = 'https://github.com/ivanvorobei/SPDiffable'
   s.source = { :git => 'https://github.com/ivanvorobei/SPDiffable.git', :tag => s.version }

Sources/SPDiffable/Collection/DataSource/SPDiffableCollectionDataSource.swift

@@ -239,6 +239,12 @@ open class SPDiffableCollectionDataSource: NSObject, SPDiffableDataSourceInterfa
                 let previousSection = sections[previousSectionIndex]
                 guard let _ = snapshot.sectionIdentifiers.first(where: { $0.id == section.id }) else { continue }
                 guard let _ = snapshot.sectionIdentifiers.first(where: { $0.id == previousSection.id }) else { continue }
+                
+                // If try move section to same index as original.
+                // This line allow skip it action.
+                // Can happen crash for collection if doing it.
+                if (previousSectionIndex + 1) == sectionIndex { continue }
+                
                 snapshot.moveSection(section, afterSection: previousSection)
             }