Clean up iconutil wrapper

Sources/Backend/Utilities/IconUtil.swift

@@ -33,33 +33,23 @@ enum IconUtil {
  process.standardOutput = pipe
  process.standardError = pipe
  process.arguments = ["iconutil", "-c", "icns", iconsetURL.lastPathComponent]
+ process.executableURL = URL(fileURLWithPath: "/usr/bin/env")
+ process.currentDirectoryURL = tempURL
 
- let envPath = "/usr/bin/env"
-
- if #available(macOS 10.13, *) {
- process.executableURL = URL(fileURLWithPath: envPath)
- process.currentDirectoryURL = tempURL
- try process.run()
- } else {
- process.launchPath = envPath
- process.currentDirectoryPath = tempURL.path
- process.launch()
- }
+ try process.run()
  process.waitUntilExit()
 
- let data: Data? = {
- let fileHandle = pipe.fileHandleForReading
- if #available(macOS 10.15.4, *) {
- return try? fileHandle.readToEnd()
- } else {
- let data = fileHandle.readDataToEndOfFile()
- return data.isEmpty ? nil : data
- }
- }()
-
  // iconutil only returns data if something went wrong
- if let data {
- throw ContextualDataError(data, context: self)
+ let fileHandle = pipe.fileHandleForReading
+ if #available(macOS 10.15.4, *) {
+ if let data = try fileHandle.readToEnd() {
+ throw ContextualDataError(data, context: self)
+ }
+ } else {
+ let data = fileHandle.readDataToEndOfFile()
+ if !data.isEmpty {
+ throw ContextualDataError(data, context: self)
+ }
  }
 
  try FileManager.default.copyItem(at: iconURL, to: outputURL)