UNC issues and updating from PA.com menu is giving errors

The problem with that is that many PortableApps.com apps still don't support directory moving (e.g. from X:\Something to X:\ rather than just Y:\ to X:\). This then raises the question: what would you map the drive as? If you have \\allspice\work\tools\portable, should Z: be mapped to \\allspice\work, \\allspice\work\tools or \\allspice\work\tools\portable? While some cases could be satisfied with this (specifically, those where the whole drive is mapped), not all can: say, for example, that you have that being C:\work\tools\portable; this would require mapping \\allspice\work to Z:\work, which can't be done. Of course, in all this I am assuming that you will not always be running it via a share, or else the behaviour could be made consistent.

For the moment, I think we can leave this as a power user feature (I don't think I've heard of anyone who doesn't know how to map a network drive trying to run portable apps from a UNC path, though that certainly doesn't indicate that it doesn't happen). I certainly haven't heard people clamouring for such functionality as you're suggesting now; if it can be demonstrated that more people would be benefited by the implementation of such a feature, we're more likely to follow it up.

#define VC_EXTRALEAN
#define WIN32_LEAN_AND_MEAN
#include "windows.h"
#include "WinNetWk.h"
#pragma comment(lib, "mpr")

#include

int _tmain(int argc, TCHAR* argv[])
{
TCHAR unc[1024]; // full path to exe.
PTSTR dir; // subfolder info.
bool map = false; // when true, map the unc to drive.
PTSTR drive = NULL; // drive letter and colon

/*
** Get path to EXE. Can be one of:
**
** P:\exe or \\server\share\exe
** P:\sub1\sub2\exe or \\server\share\sub1\sub2\exe
**
** in any case, exe is not interesting so drop it, bt leave trailing \
*/
::GetModuleFileName(NULL, unc, 1024);
dir = _tcsrchr(unc, _T('\\'));
dir[1] = 0;

/*
** Unc's start with \\
** Determine if program was started from UNC
** TODO: may need additional testing for the seldom used \\?\ syntax
*/
if (unc == _tcsstr(unc, _T("\\\\")))
{
/*
** \\server\share\ or \\server\share\sub1\sub2\
** Cut \\server\share\
** \\server\share\sub1\sub2\
** here ---^
** unc will hold \\server\share
** dir will hold nothing or sub1\sub2
*/
dir = _tcschr(unc + 2, _T('\\'));
dir = _tcschr(dir + 1, _T('\\'));
*dir++ = 0;

/*
** TODO: look for an existing drive letter that already connects
** to same UNC. Save drive letter for use below.
*/

/*
** If no mapping found,
** TODO: use 'next available' drive or configuration setting?
*/
map = (NULL == drive);
if (map)
{
drive = _T("P:");

/*
** Create a new mapping to unc using existing credentails.
** (should always work since code is running from there)
*/
NETRESOURCE nr = {0};
DWORD result;

nr.dwType = RESOURCETYPE_DISK;
nr.lpLocalName = drive;
nr.lpRemoteName = unc;

result = WNetAddConnection2(&nr,
NULL,
NULL,
CONNECT_TEMPORARY | CONNECT_CURRENT_MEDIA);
if (NO_ERROR != result)
drive = NULL; // handle below?
}

if (NULL != drive)
{
/*
** A new or existing drive letter was found.
** Assemble new path from those pieces.
**
** TODO: buffers overlap, but should aways be
** shoreter than \\x\y. Test, Test, Test.
*/
_tcscpy_s(unc, 1024, drive);
_tcscat_s(unc, 1024, 0 != *dir ? dir : _T("\\"));
}
}

/*
** At this point, unc contains the folder where the EXE lives
** and it always ends with a \.
** If drive mapping was successful or unnecessary this path will
** start with a drive letter, otherwise it will still be a UNC.
** TODO: abort the launch or blunder ahead
** use this path to find and launch PortableAppsLauncher.exe
*/

return 0;
}

The UNC path restriction is very definitely there for PortableApps.com's sake, not for the base app's sake.

From a UNC path, what does %PAL:Drive% mean? It would require yet another reworking of how paths are handled in PAL, and I'm not convinced it can be done correctly (we really do depend on drive switching for a number of things).

It would require some work in PAL and a considerable amount of extra work on all apps, to support what is a corner case. Since supporting mapping to a drive letter in the Platform is an activity which can be implemented more simply, only once and in one place, I think it should be considered a better and more efficient solution (the only detractor from it is that it would require the Platform to be run). Especially as we're more likely to have apps working from a mapped network drive than from a UNC path.