User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.5112.81 Safari/537.36 Edg/104.0.1293.54

Steps to reproduce:

Try to download alt.binaries.pictures.gardens, it has 336 messages.

Actual results:

 NS_BASE_STREAM_WOULD_BLOCK: Component returned failure code: 0x80470007 (NS_BASE_STREAM_WOULD_BLOCK) [nsIOutputStream.write] 4 NntpService.jsm:142
    onData resource:///modules/NntpService.jsm:142
    _actionArticleResponse resource:///modules/NntpClient.jsm:678
    read resource:///modules/LineReader.jsm:51
    _actionArticleResponse resource:///modules/NntpClient.jsm:670
    _onData resource:///modules/NntpClient.jsm:191
    editFolder chrome://messenger/content/folderPane.js:3447
    oncommand chrome://messenger/content/messenger.xhtml:1

Expected results:

It should download as with the old C++ implementation.

Note:

1. Sometimes a few messages are downloaded, but the error shows at some stage.
2. Downloading is necessary for body search

Sorry I can't access alt.binaries.pictures.gardens, can you reproduce it with any newsgroup?

We've seen it on various newsgroups, the garden stuff was just a limited example. It's available for free via news.eternal-september.org which is a common free server. We suggest creating an account there and adding downloading entire newsgroups to your test plans if it can't be automated.

Without a consumer, outputStream.write will fail after buffer become full.
Add a test to fetch a large message.

Pushed by mkmelin@iki.fi:
https://hg.mozilla.org/comm-central/rev/09f0f3bb58b7
Do not write to stream if NntpService.fetchMessage has no consumer. r=mkmelin

Comment on attachment 9290586 [details]
Bug 1785773 - Do not write to stream if NntpService.fetchMessage has no consumer. r=mkmelin

[Approval Request Comment]
Regression caused by (bug #): bug nntp-js
User impact if declined: Download large news article for offline use doesn't work.
Testing completed (on c-c, etc.): beta
Risk to taking this patch (and alternatives if risky): low

Please also take the lint fix in comment 5, thanks.

Comment on attachment 9290586 [details]
Bug 1785773 - Do not write to stream if NntpService.fetchMessage has no consumer. r=mkmelin

[Triage Comment]
Approved for esr102

Thunderbird 102.3.0:
https://hg.mozilla.org/releases/comm-esr102/rev/4b80a35cec5b
https://hg.mozilla.org/releases/comm-esr102/rev/c7e8c7f077b4