Merge pull request #1521 from phausler/data_sync_master

Author: swift-ci

Foundation/Data.swift

@@ -38,6 +38,22 @@ internal func __NSDataIsCompact(_ data: NSData) -> Bool {
 import _SwiftFoundationOverlayShims
 import _SwiftCoreFoundationOverlayShims
 
+internal func __NSDataIsCompact(_ data: NSData) -> Bool {
+    if #available(OSX 10.10, iOS 8.0, tvOS 9.0, watchOS 2.0, *) {
+        return data._isCompact()
+    } else {
+        var compact = true
+        let len = data.length
+        data.enumerateBytes { (_, byteRange, stop) in
+            if byteRange.length != len {
+                compact = false
+            }
+            stop.pointee = true
+        }
+        return compact
+    }
+}
+
 #endif
 
 public final class _DataStorage {
@@ -127,7 +143,7 @@ public final class _DataStorage {
         case .mutable:
             return try apply(UnsafeRawBufferPointer(start: _bytes?.advanced(by: range.lowerBound - _offset), count: Swift.min(range.count, _length)))
         case .customReference(let d):
-            if d._isCompact() {
+            if __NSDataIsCompact(d) {
                 let len = d.length
                 guard len > 0 else {
                     return try apply(UnsafeRawBufferPointer(start: nil, count: 0))
@@ -136,6 +152,7 @@ public final class _DataStorage {
             } else {
                 var buffer = UnsafeMutableRawBufferPointer.allocate(byteCount: range.count, alignment: MemoryLayout<UInt>.alignment)
                 defer { buffer.deallocate() }
+
                 let sliceRange = NSRange(location: range.lowerBound - _offset, length: range.count)
                 var enumerated = 0
                 d.enumerateBytes { (ptr, byteRange, stop) in
@@ -160,7 +177,7 @@ public final class _DataStorage {
                 return try apply(UnsafeRawBufferPointer(buffer))
             }
         case .customMutableReference(let d):
-            if d._isCompact() {
+            if __NSDataIsCompact(d) {
                 let len = d.length
                 guard len > 0 else {
                     return try apply(UnsafeRawBufferPointer(start: nil, count: 0))
@@ -169,6 +186,7 @@ public final class _DataStorage {
             } else {
                 var buffer = UnsafeMutableRawBufferPointer.allocate(byteCount: range.count, alignment: MemoryLayout<UInt>.alignment)
                 defer { buffer.deallocate() }
+
                 let sliceRange = NSRange(location: range.lowerBound - _offset, length: range.count)
                 var enumerated = 0
                 d.enumerateBytes { (ptr, byteRange, stop) in
@@ -507,7 +525,7 @@ public final class _DataStorage {
         case .mutable:
             return _bytes!.advanced(by: index - _offset).assumingMemoryBound(to: UInt8.self).pointee
         case .customReference(let d):
-            if d._isCompact() {
+            if __NSDataIsCompact(d) {
                 return d.bytes.advanced(by: index - _offset).assumingMemoryBound(to: UInt8.self).pointee
             } else {
                 var byte: UInt8 = 0
@@ -521,7 +539,7 @@ public final class _DataStorage {
                 return byte
             }
         case .customMutableReference(let d):
-            if d._isCompact() {
+            if __NSDataIsCompact(d) {
                 return d.bytes.advanced(by: index - _offset).assumingMemoryBound(to: UInt8.self).pointee
             } else {
                 var byte: UInt8 = 0
@@ -1541,7 +1559,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     /// - parameter buffer: The replacement bytes.
     @inline(__always)
     public mutating func replaceSubrange<SourceType>(_ subrange: Range<Index>, with buffer: UnsafeBufferPointer<SourceType>) {
-        guard !buffer.isEmpty else { return }
+        guard !buffer.isEmpty  else { return }
         replaceSubrange(subrange, with: buffer.baseAddress!, count: buffer.count * MemoryLayout<SourceType>.stride)
     }