Core
CORE-41959 print preview broken for multipart/* documents (breaks mail printing)
CORE-42479 Crash on installing extension
CORE-42024 Stack exhaustion due to deeply recursive compilation of RE construct
CORE-42088 Avoid blowing the stack when compiling regexp loop sequences

Desktop
DSK-349634 Search engines are with no icons
DSK-349628 Opera should not crash on exit after checking for mail/RSS

Mail
Two-lined message list
New message display window
Message grouping
Support for Pinning, mapped to IMAP \Flagged
Quick Reply redesign
New overlay dialogs for the mail view settings
Ctrl-Enter to send quick reply
Update mailproviders.xml for iCloud
DSK-201988 Message displayed even though no message selected
DSK-222658 Show image enclosures inline in feeds
DSK-260891 Paste with mouse in Mail Compose window is mouse position dependant
DSK-277400 Message formatting is slow
DSK-309380 Enable Fit to Width for Opera Mail
DSK-311982 Show account connection status in mail panel
DSK-319023 Unread in Mail panel returns after a restart
DSK-340859 Messages in INBOX are not fetched before the folder is selected on Gmail accounts
DSK-342882 Mail data is corrupted, all mail redownloads
DSK-343439 after deleting a block of mail, selected message is not next to the selected block
DSK-343444 Cannot Rename Folders for RSS Feeds
DSK-344164 Remove '[x] from loading database progress bar
DSK-344565 Need to mark message as read twice before it is read
DSK-345346 Expunged messages in other clients are not expunged in Opera Mail
DSK-348639 Broken progress bar skin with windows native skin

Bugfixes:
– AIM: Improved avatar support
– MSN: Improved group chat entry UI
– MSN: Fixed issue with one-to-one chats
– Jabber: GTalk improvements with status modes

New Features

Drivers for the LG Optimus 2X, HTC Incredible S, Samsung Stratosphere and the Kobo Vox
Closes tickets: 886558 , 885058 , 884762 , 884039

Get books: Add ebookpoint.pl store
Support hour/minute/seconds in datetime format strings in the template language and in tweaks
Bug Fixes

Fix Book detils preferences showing custom columns even after they have been deleted
Closes tickets: 884799

Replace use of insecure tempfile in the bundled rtf2xml library.
Closes tickets: 885245

Remove the suid mount helper used on linux and bsd, as it proved impossible to make it secure.
Closes tickets: 885027

This means that if you are on BSD or an older linux distribution, without support for udisks, device detection will no longer work in calibre. You will have to either mount the devices by hand before starting calibre, or stick with version 0.8.24 (the vulnerability in the mount helper is a privilege escalation, which is relatively harmless on the vast majority of single user systems).

Do not error out if there is an invalid regex for title sort set in tweaks
Content server: Fix another place where --url-prefix was forgotten
Closes tickets: 885332

HTML Input: Limit memory consumption when converting HTML files that link to large binary files.
Closes tickets: 884821

T1 driver: Workaround for T1 showing error messages when opening some news downloads on the device
Kobo driver: Fix longstanding bug that would prevent re-adding a epub that has been previously deleted from the Kobo using calibre
Fix partial cover search not resuming after pressing back in the metadata download dialog
Closes tickets: 875196

T1 driver: Fix auto refresh covers option
Content server: Do not show tracebacks in HTML output when not running in develop mode
Textile output; Fix out of memory issue when dealing with large margins.
New news sources

b365 Realitatea and Catavencii by Silviu Cotoara
Various Greek news sources by Stelios
Real world economics blog by Julio Map
Improved news sources

The Independent
Die Zeit subscription version
NIN online
Science News
Updated Daily Mirror
Science AAAS