Reset extended attributes of the base directories.

Library/Homebrew/cask/artifact/moved.rb

@@ -2,6 +2,7 @@
 # frozen_string_literal: true
 
 require "cask/artifact/relocated"
+require "cask/quarantine"
 
 module Cask
   module Artifact
@@ -97,7 +98,9 @@ module Cask
             command.run!("/bin/cp", args: ["-pR", "#{source}/*", "#{source}/.*", "#{target}/"],
                                     sudo: true)
           end
-          # TODO: copy extended attributes
+          unless Quarantine.copy_xattrs(source, target)
+            opoo "Unable to transfer extended attributes on the root directory"
+          end
           source.rmtree
         elsif target.dirname.writable?
           FileUtils.move(source, target)

Library/Homebrew/cask/quarantine.rb

@@ -14,6 +14,7 @@ module Cask
     QUARANTINE_ATTRIBUTE = "com.apple.quarantine"
 
     QUARANTINE_SCRIPT = (HOMEBREW_LIBRARY_PATH/"cask/utils/quarantine.swift").freeze
+    COPY_XATTRS_SCRIPT = (HOMEBREW_LIBRARY_PATH/"cask/utils/copy-xattrs.swift").freeze
 
     def self.swift
       @swift ||= DevelopmentTools.locate("swift")
@@ -174,5 +175,18 @@ module Cask
 
       raise CaskQuarantinePropagationError.new(to, quarantiner.stderr)
     end
+
+    def self.copy_xattrs(from, to)
+      odebug "Copying xattrs from #{from} to #{to}"
+
+      copier = system_command!(swift,
+                               args: [
+                                 *swift_target_args,
+                                 COPY_XATTRS_SCRIPT,
+                                 from,
+                                 to,
+                               ])
+      copier.success?
+    end
   end
 end

Library/Homebrew/cask/utils/copy-xattrs.swift

@@ -0,0 +1,80 @@
+#!/usr/bin/swift
+
+import Foundation
+
+struct SwiftErr: TextOutputStream {
+    public static var stream = SwiftErr()
+
+    mutating func write(_ string: String) {
+        fputs(string, stderr)
+    }
+}
+
+guard CommandLine.arguments.count >= 3 else {
+    print("Usage: swift copy-xattrs.swift <source> <dest>")
+    exit(2)
+}
+
+CommandLine.arguments[2].withCString { destPath in
+    let destNamesLen = listxattr(destPath, nil, 0, 0)
+    if destNamesLen == -1 {
+        print("listxattr for destination failed: \(errno)", to: &SwiftErr.stream)
+        exit(1)
+    }
+    let destNamesBuf = UnsafeMutablePointer<Int8>.allocate(capacity: destNamesLen)
+    if listxattr(destPath, destNamesBuf, destNamesLen, 0) != destNamesLen {
+        print("Attributes changed during system call", to: &SwiftErr.stream)
+        exit(1)
+    }
+
+    var destNamesIdx = 0
+    while destNamesIdx < destNamesLen {
+        let attribute = destNamesBuf + destNamesIdx
+
+        if removexattr(destPath, attribute, 0) != 0 {
+            print("removexattr for \(String(cString: attribute)) failed: \(errno)", to: &SwiftErr.stream)
+            exit(1)
+        }
+
+        destNamesIdx += strlen(attribute) + 1
+    }
+    destNamesBuf.deallocate()
+
+    CommandLine.arguments[1].withCString { sourcePath in
+        let sourceNamesLen = listxattr(sourcePath, nil, 0, 0)
+        if sourceNamesLen == -1 {
+            print("listxattr for source failed: \(errno)", to: &SwiftErr.stream)
+            exit(1)
+        }
+        let sourceNamesBuf = UnsafeMutablePointer<Int8>.allocate(capacity: sourceNamesLen)
+        if listxattr(sourcePath, sourceNamesBuf, sourceNamesLen, 0) != sourceNamesLen {
+            print("Attributes changed during system call", to: &SwiftErr.stream)
+            exit(1)
+        }
+
+        var sourceNamesIdx = 0
+        while sourceNamesIdx < sourceNamesLen {
+            let attribute = sourceNamesBuf + sourceNamesIdx
+
+            let valueLen = getxattr(sourcePath, attribute, nil, 0, 0, 0)
+            if valueLen == -1 {
+                print("getxattr for \(String(cString: attribute)) failed: \(errno)", to: &SwiftErr.stream)
+                exit(1)
+            }
+            let valueBuf = UnsafeMutablePointer<Int8>.allocate(capacity: valueLen)
+            if getxattr(sourcePath, attribute, valueBuf, valueLen, 0, 0) != valueLen {
+                print("Attributes changed during system call", to: &SwiftErr.stream)
+                exit(1)
+            }
+
+            if setxattr(destPath, attribute, valueBuf, valueLen, 0, 0) != 0 {
+                print("setxattr for \(String(cString: attribute)) failed: \(errno)", to: &SwiftErr.stream)
+                exit(1)
+            }
+
+            valueBuf.deallocate()
+            sourceNamesIdx += strlen(attribute) + 1
+        }
+        sourceNamesBuf.deallocate()
+    }
+}