Multi-selected files open in random order, not by name

[jeet0474]

Is your feature request related to a problem? Please describe.
I open a folder, say D:\@ML\module1, select lec1 to lec8, hit Enter. Tabs open all scattered. Not lec1, lec2, lec3. Just random.

And no it's not my clicking. I tried selecting them in order too. Still scattered. So it's not selection order. Sumatra just takes whatever order Windows gives.

I looked into it a bit. The Windows file picker returns files in some shell order thats not name order and not click order. Then StartLoadDocuments in src/SumatraPDF.cpp just makes tabs in that same order. Drag and drop does the same thing since it goes through the same function.

Describe the solution you'd like
Just sort the list before making tabs. The helper already exists (SortNatural in src/base/StrVec.cpp) and is already used in the same file. One line, right after pathsToLoad is built (around line 4493):

if (pathsToLoad.IsEmpty()) {
    return;
}
SortNatural(&pathsToLoad);   // open tabs in name order (lec1, lec2, ... lec10)

Its natural sort so lec2 comes before lec10, not the dumb lec1, lec10, lec2.

Describe alternatives you've considered
Maybe hide it behind a setting if someone actually likes the random/time/selection/etc order. Ill let you decide. For me name order is just the obvious thing when opening a pile of lectures.

Additional context
So yeah. I found the bug, traced it, wrote the fix. But I am not gonna install the whole Visual Studio build setup just to test ONE line lol. By the time I clone the repo you could already have it built. So here, free diagnosis and a one liner, im just gonna leave this here and slowly walk away 😄

[GitHubRulesOK]

Hmm this was mentioned several time over the 20 years and the problem is how Windows orders for drag and drop ETC so here are some files in Windows natural sort per explorer and dropped on SumatraPDF they are opened in that order as shown by first tab is first file !

[jeet0474]

Thanks! Yeah drag and drop works, opens in the order I sort in Explorer.

And Ctrl+O inside Sumatra works too, if I multi select there they come out sorted just like drag and drop.

The only case that breaks for me is opening straight from Windows Explorer. I have Sumatra set as default, so I go into a folder, select the files I want (lec1 to lec8) and hit Enter. Sumatra opens them but the tabs come out scattered, not in name order. Thats the one that doesn't sort.

[GitHubRulesOK]

OK I am not the developer so it is @kjk will need to say how that might be handled because it is not retaining the files even when selected one by one in order so the log shows the random effect that enter causes even when all files are identical seen here sumatraPDF is showing in a random order but respects that !! however when asked in true numeric order they are also random order

[jeet0474]

Ah that log explains it. So from Explorer the files aren't sent as one list, Windows sends them one at a time over WM_COPYDATA and they get queued in gDdeOpenOnStartup in whatever order they arrive, which is random. So the scatter is in that queue, not the file picker. My earlier one liner in the picker wouldnt have helped this case at all.

So the real fix would be to sort that queue before it opens, in SumatraStartup.cpp around where gDdeOpenOnStartup is drained (line something 2947):

SortNatural(&gDdeOpenOnStartup);

On the manual reorder, I know Ctrl+Shift+PageUp/Down and dragging tabs exist, but I cant really use them. My tab names are long and the numbers at the end get cut off on the tab bar, so I cant tell which tab is which while moving them.

Where I can read the full names is the Ctrl+Tab list in sticky mode (Space). So the idea is: let me reorder tabs from inside that list, like a shortcut to move the highlighted entry up/down. Full names are visible there so it'd actually be usable.

The auto sort is still my main ask, but this would be a nice fallback (and handy in general for reordering a big pile of tabs).

[GitHubRulesOK]

@jeet0474
Again as I am not the developer (simply an observer)
I am unsure why the order is altered that second test shows that the sequence of multiple files one AFTER the other is shuffled, (presumably by async threading) and will produce such a randomised sequencing unless marshalled by name EXTERNALLY in the caller.
The point of me using a numeric loop was to see what happens with a numeric sequence in a short interval irrespective of "size/format weighting" as all those files are copies of one identical pdf, so no reason to differ. the test run has NO history so should be handled in the order given. What is happening is they are displayed in some ready to show order and setting "lazy" makes no difference as it is still odd like 5 6 2 4 1 3 so is it windows handing over after holding them back as a single command works . AFAIK it is Windows interferes due to its own transmission of order.

When left to SumatraPDF as a single command it works

[GitHubRulesOK]

@jeet0474
my observation is that windows needs a few seconds between the files in sequence before it will hand over in order as shown here

2 seconds is still a fail