I noticed this in the OnEvent() handler of CoreMain.lua (line 185 in version 5.0.0):


elseif (event == "PLAYER_LOGOUT") then
AucAdvanced.Scan.Commit(true)
private.OnUnload()
AucAdvanced.Scan.LogoutCommit()


The OnUnload calls the OnUnload() functions for all loaded modules;

Auc-ScanData's OnUnload() packs the scan image into a string (ScanData.lua line 326+);

AucAdvanced.Scan.LogoutCommit() forces any suspended Commit coroutine to run until completion, but ---

The coroutine function expects the scan image to still be a table! (e.g CoreScan.lua line 652 attempts to call table.insert() on the string).


I'm not sure that this can actually corrupt the scan data string (I think it would just throw a lua error and then stop), but any uncommited scan data will be lost.

Looks like the OnUnload() call should go last.

might this be what's causing all those intermittent scandata corruptions?

I was hunting for a possible cause of http://jira.norganna.org/browse/ADV-111

However I don't see how this could cause the corruption in the sample file provided by jlva321 :(

At worst, I think this would cause Auc-ScanData to try to save an incomplete scan image - but looking at the packing code, I think it should then generate a 'valid' string which just unpacks into an incomplete table again. Instead, the string itself is somehow getting corrupted, so that it fails to unpack at load time. I would expect that calling table.insert or table.remove on a string should not actually modify the string.

We shall see though :)

kk, lets see what this fixes :)

A suggestion though - currently if Auc-ScanData fails to load the image string, it simply prints a message to 'chat'

I suspect that most users won't notice this message, because they will immedialty get another error message popping up in their face, when AA trys to use the bad data.

Maybe this should be 'promoted' to an Error message, so that it is more likely to be reported correctly?

Hmm, look at what happens to fData.image in this snippet from ScanData.lua (line 310+)

if fData.image and type(fData.image) == "string" then
local loader, err = loadstring(fData.image)
if (loader) then
fData.image = loader()
collectgarbage()
else
print("Error loading scan image: {{", err, "}}")
end


Initially fData.image is a string (the packed image)

If loadstring succeeds then fData.image is replaced with a table (the return value from the loader() call)

If loadstring fails then fData.image is unchanged - i.e. it's still a string

This will almost immediatly throw a lua error elsewhere, when another function expects the image to be a table -

Note in CoreScan.lua line 500:

for i = 1, #scandata.image do
id = scandata.image[i][Const.ID]
table.insert(idList, id)


scandata.image is (still) a string
#scandata.image returns the length of the string
scandata.image[i] returns nil (does not throw an error like I expected!)
scandata.image[i][Const.ID] then reports that you're trying to index a nil value

Added http://jira.norganna.org/browse/SDAT-10