appshell.fs.showOpenDialog: Windows wchar_t buffer is too small

[redmunds]

Moved from https://github.com/adobe/brackets-shell/issues/330 by @bgagnon

The wchart_t buffer (szFile) is of size MAX_PATH (260 on my platform). This is not sufficient to handle medium size collections of UNC paths on Windows, particularly on network drives.

When "allowMultipleSelection" is true, the buffer should be large enough to accommodate collections of paths. In my particular installation, I needed to support several thousand file selections to deal with image sequences.

[gruehle]

Medium priority to @JeffryBooher. We should definitely use a larger buffer size here...

[njx]

Nominating for sprint 35.

[redmunds]

@JeffryBooher I merged adobe/brackets-shell#397 to get longer file paths, but I don't see how it fixes the request for "several thousand file selections", so I'm leaving this bug open.

[redmunds]

@bgagnon We're not really sure what you're asking for here. Can you provide a use case where you would need a collection of "several thousand file selections"? Thanks.

[njx]

Closing since we haven't heard back about the use case that would require an excessively long buffer.