dev/core#769 - Fix for ZipArchive->open() PHP bug

[Edzelopez]

Overview

There is an issue with the ZipArchive class' open() method. In previous versions of PHP when the only flag passed to the method was the ZipArchive::OVERWRITE, the method also created non-existing archives.
Since PHP 5.6 the OVERWRITE flag alone cannot create new archives which breaks compatibility.

Before

Zip files were created if they did not exist by simply specifying the ZIPARCHIVE::OVERWRITE flag.

After

ZipArchive::ER_OPEN error code is returned (cannot open zip file).

Technical Details

Bug report: https://bugs.php.net/bug.php?id=71064

[civibot]

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[seamuslee001]

Jenkins re test this please

[eileenmcnaughton]

This is one of those features that shouldn't be in core but since it is & this is a trivial change by the main user /supporter of this I'm going to merge it