1854361 - [imap-js] wrongly stores invalid message in cache

Status: RESOLVED FIXED

(MailNews Core :: Networking: IMAP, defect)

Description

[John Bieling]

Attachment: sync settings.JPG

While debugging Bug 1851074 I also checked how the js version of our IMAP implementation is handling the situation and found a strange behavior in ImapChannel.jsm:onCacheEntryAvailable (link)

STR

• setup the sync settings of an IMAP account as shown in the attached image

• set a breakpoint in onCacheEntryAvailable

• send yourself a couple of test messages which have an attachment to make sure they are larger than 1KB and hit the no-download-criteria

• cycle through the messages and observe the new and status parameters of onCacheEntryAvailable

• status will always be 0 and new will be true the first time we view a message

• once new is false, the message will be pulled from _readFromCacheStream in the last line of onCacheEntryAvailable

• restarting Thunderbird will make new true again when opening a message for the first time

• make sure all messages have been viewed at least once and disconnect your network

• the messages are still pulled from the cache

• keep the network disabled and restart TB

• again cycle through the messages

• when accessing a message for the first time, parameter newwill be true and the function tries to read the message from the server and fails (there is a connection error) but it looks like it saves an empty msgHdr in the cache

• any follow up access will not trigger a connection error, because it pulls the empty header from the cache and returns the entire operation as a success

• enable your network connection again

• the messages will still not show up, because it continues to pull the empty msgHdr from the cache.

Comment 1

[John Bieling]

We should not store empty message headers in case of connection errors and keep reporting the connection errors on all follow-up read requests, until the connection comes back again.

Comment 2

[John Bieling]

Attachment: Bug 1854361 - Remove invalid cache, if message could not be fetched from server. r=#thunderbird-reviewers

Comment 3

[John Bieling]

Try: https://treeherder.mozilla.org/jobs?repo=try-comm-central&revision=4e135b0322711c6625a5ad77520045f42719d2e2

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/a51fb7ea975c
Remove invalid cache, if message could not be fetched from server. r=mkmelin