41292 - While downloading news headers: Error loading with many headers to download

Status: VERIFIED FIXED

(MailNews Core :: Networking: NNTP, defect, P3)

Description

[a-huntwork]

For the past several weeks, while downloading news headers, it eventually
happens that no headers download from a newsgroup even though there are headers
to download and an error message goes to the console that says:
Error loading with many headers to download
This always happens eventually, but I know of no certain way to cause it to
occur quickly.  I'm on linux using 2000060120 with a completely new profile, but
I've seen it in every build I've tried for I'd say the past month.  I'm using
news.mozilla.org.  I'm subscribed to more than 10 ng's and I don't see any
preference for which ng it errors on. If I can provide any more info, just ask.

Comment 1

[Alec Flett]

I see this too... it's really wierd, and I haven't figured out a way to 
consistently reproduce it.

Comment 2

[a-huntwork]

After the "Error loading" message occurs, clicking on one of my imap mail
folders, then clicking back on the same news folder causes the following
javascript exception:
JavaScript error:  line 0: uncaught exception: [Exception... "Component returned
failure code: 0x80004002 (NS_NOINTERFACE) [nsIMsgFolder.updateFolder]"
nsresult: "0x80004002 (NS_NOINTERFACE)"  location: "JS frame :: chrome:
//messenger/content/commandglue.js :: ChangeFolderByURI :: line 189"  data: no]

In the past, this exception has occurred every time I have gone to a mail folder
then back to the news folder, but now it only happens occasionally.  When the
exception does not occur, the new headers are correctly downloaded and
displayed.  Hope this helps.

Comment 3

[a-huntwork]

Additional weird data point:  I see this problem frequently when changing from
one newsgroup to another, e.g., I'm currently on npm.xpcom and I change to
npm.ui, but I have never (as far as I know) seen this problem when changing from
one of my imap folders to a newsgroup.

Comment 4

[(not reading, please use [e-mail] instead)]

this sounds bad.  I need to investigate.

Comment 5

[(not reading, please use [e-mail] instead)]

marking m17, nsbeta2.

if I can't reproduce it, it will get moved off.

Comment 6

[leger]

Putting on [nsbeta2+] radar for beta2 fix. 

Comment 7

[David :Bienvenu]

this is the same as 41842 - one should be a dup of the other.

Comment 8

[jefft]

*** Bug 41842 has been marked as a duplicate of this bug. ***

Comment 9

[David :Bienvenu]

guess I'll take this since Seth is out.

Comment 10

[David :Bienvenu]

accepting

Comment 11

[David :Bienvenu]

Adding approximate ETA - it's hard to estimate because this is very difficult to
reproduce.

Comment 12

[David :Bienvenu]

This is failing in nsNNTPProtocol::InitializeNewsFolderFromUri(const char *uri)
 - the rdf resource for the uri passed in is not an nsIMsgNewsFolder, so the QI
fails. I'm not sure why this sometimes happens. The uri passed in is of the form
news://news:119/mcom.test - it's suspicious that the port designation is in
there but it seems to work sometimes when the port is there...

Comment 13

[David :Bienvenu]

Attachment: proposed fix

Comment 14

[David :Bienvenu]

This is very strange - the resource that was supposed to be a news folder turned
out to be a news message. The reason seems to be that the rdf factory cache does
a strncmp on the url scheme, with the length limit set to the length of the
scheme we're looking for, so if the previous scheme was "news_message", and the
new scheme is "news", it uses the factory for "news_message". If I'm right, it's
hard to believe that this doesn't cause other random problems. Anyway, the
attached patch seems to fix the problem for me. The fix is just to compare the
lengths of the new scheme and the cached scheme. Please let me know, thanks!

Comment 15

[a-huntwork]

If you check this in, I can try it out in a nightly and tell you if it fixes
this problem.  Doesn't your patch fix a serious problem regardless of whether it
fixes this bug, and shouldn't it therefore just be checked in?

Comment 16

[David :Bienvenu]

I need a code review before I can check anything in, and that goes double for
changes to other people's code!

Comment 17

[a-huntwork]

What I meant was that you could get this reviewed and checked in not necessarily
as a fix for this bug, if you're not sure it does in fact fix this, but instead
as a fix for a bug in the RDF service.  Then I could verify that it fixes this
bug in a nightly, which are the only builds i have access to.  I only mentioned
it because that's the only way I could help verify that this bug is fixed, and
I'd love to do so.

Comment 18

[David :Bienvenu]

Oh, I see. Yes, I'm sure this will get checked in, and I'm reasonably sure it
will fix this problem. It's only the difficulty in reproducing this that makes
me not 100% sure that it fixes this problem. That, and I'm a little suprised
this problem doesn't happen more often.

Comment 19

[David :Bienvenu]

fix checked in.

Comment 20

[a-huntwork]

This looks fixed to me also.  I've been playing with newsgroups off and on all
day today (since today's build came out) and have been unable to cause this bug
to manifest itself.  In a build from over the weekend I saw this bug after only
a few minutes of playing with newsgroups, and that was a typical time period
necessary to cause this bug in the past.  Way to go [e-mail].  This
was the big pain-in-the-ass mozilla bug for me.

Comment 21

[Karen Huang]

Verified on Linux 07-20-09-M17 commercial build
Verified no error displaying when loading with many headers (even more than 
(1000+) amount of headers) Marking as verified!!

Comment 22

[Henrik Gemal]

Just seen this one in todays build 20010423.
Will try to find a way to reproduce...

Comment 23

[Henrik Gemal]

btw: saw this on win2k

Comment 24

[Henrik Gemal]

When switching between reading news postings and local folders I sometimes get:

Error loading with many headers to download: [Exception... "Component returned
failure code: 0xc1f30001 (NS_ERROR_NOT_INITIALIZED) [nsIMsgFolder.updateFolder]"
 nsresult: "0xc1f30001 (NS_ERROR_NOT_INITIALIZED)"  location: "JS frame ::
chrome://messenger/content/commandglue.js :: ChangeFolderByURI :: line 219" 
data: no]

It's pretty hard to describe how to reproduce buts it when having both a
newsgroup and local folder open and switching between them.
build 20010424

Comment 25

[David :Bienvenu]

Henrik, you'll get that error loading a local folder if the local folder summary
file is out of date with the local folder - it has nothing to do with news. So I
don't think it's this bug at all.

Comment 26

[Henrik Gemal]

please explain: "it's not a bug" ?

Comment 27

[David :Bienvenu]

"not this bug" Gemal, not "not a bug". This bug is about getting that msg while
downloading news headers, and I was trying to say that you get that msg when
opening a local folder and the summary file is out of date (news summary files
don't get out of date in that way).

Comment 28

[David :Bienvenu]

I believe this should be fixed on the trunk now as part of another fix for
handling corrupt news db's - please re-open if you see it again.

Comment 29

[[e-mail] (gone - use [e-mail] instead)]

I had 18 newsgroups, all brand-new to which I subscribed and proceeded to
download all the headers in each.  They all originated from news.mozilla.org.

RedHat 7.1 - 2001-08-15-14
Windows 2K - 2001-08-16-03
Mac OS 9.1 - 2001-08-16-08

Verified Fixed (again)