Description:
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If a directory name in a path for a file in zip archive ends with a colon (:) the file will be extracted to the root dir instead of to its original directory.

Test script:
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<?php

$file = tempnam("/tmp", "ziptest");
$target = tempnam("/tmp", "ziptest");
unlink($target);
mkdir($target);

$zip = new ZipArchive;
$zip->open($file);
$zip->addFromString("dir/test:/filename.txt", "contents");
$zip->addFromString("dir/test:a/filename.txt", "contents");
$zip->addFromString("dir/test/filename.txt", "contents");
$zip->close();

$zip->open($file);
$zip->extractTo($target, "dir/test:/filename.txt");
$zip->extractTo($target, "dir/test:a/filename.txt");
$zip->extractTo($target, "dir/test/filename.txt");
$zip->close();

unlink($file);



Expected result:
----------------
Expected behavior would be that the three files were extracted to the following paths:
/tmp/ziptest/dir/test:/filename.txt
/tmp/ziptest/dir/test:a/filename.txt
/tmp/ziptest/dir/test/filename.txt

Actual result:
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If you run the test script, three files will be extracted to the following paths:
/tmp/ziptest/filename.txt
/tmp/ziptest/dir/test:a/filename.txt
/tmp/ziptest/dir/test/filename.txt