General:
Force video sources to all have the same capabilities. This reduces the number of times video must be scaled down, saving CPU time. (Jakub Adam) (half of #13095)
Starting multiple video calls and ending one no longer causes the other calls to stop sending audio and video. (Jakub Adam) (#12758, #13237)
Perl bindings now respect LDFLAGS. (Peter Volkov, Markos Chandras) (#12638)
Added AddTrust External Root CA. (#11554)
Resolve some issues validating X.509 certificates signed off the CAcert Class 3 intermediate cert when using the GnuTLS SSL/TLS plugin.
Gadu-Gadu:
Don't drop whole messages when text is colored. (Jan Zachorowski) (#13259)
Groupwise:
Don't show two windows when using "Get Info" on a buddy. (Gabriel Burt; Novell, Inc.) (#13108)
IRC:
Don't send ISON messages longer than 512 bytes. (Jeffrey Honig) (#9692)
libpurple:
Stop sending audio when placing a call on hold. (Jakub Adam) (#13032)
Stop translating gpointers to ints in the dbus API. This removes functions from the dbus API. (The openSUSE Project) (#12507)
Fix D-Bus introspection calls that omit the interface parameter. (Tom Samstag) (#13073)
Fixed bugs in purple_str_to_time() that caused the most recent 'make check' failures. (Nader Morshed) (#13131)
Correct an issue that caused some UIs other than Pidgin or Finch to leave a buddy in the "is typing" state. (Jan Kaluza)
Fix potential information disclosure issues in the Cipher code. (Julia Lawall)
Pidgin:
Support using the Page Up and Page Down keys on the numeric keypad in the conversation window. (Ryan Flegel) (#13127)
Fix a few memory leaks. (Nader Morshed) (#13162)
Support rendering strikethrough when received as in-line CSS. (#13168)
Editable comboboxes are now more friendly to some GTK+ themes. (Hugo Pereira Da Costa) (#13164).
Plugins:
The Voice/Video Settings plugin no longer resets selected devices to defaults. (Jakub Adam) (#13044)
The Voice/Video Settings plugin no longer crashes when a stored device name is not found in the list of available devices. (Jakub Adam) (#13238)
The Autoaccept plugin now allows disabling filename escaping. (Rok Mandeljc) (half of #11459)
The Autoaccept plugin now allows choosing Reject/Ask/Accept for non-buddies. (Rok Mandeljc) (half of #11459)
QQ:
QQ2008 is now the default protocol version. (Michael Terry) (#11635)
XMPP:
Don't crash when receiving an unexpected/invalid jingle transport type. (Nikita Kozlov) (#13136)
Handle Connection: Close headers for BOSH, when the server does not terminate the connection itself. (#13008)
Improved parsing for DIGEST-MD5, which should resolve issues connecting to some jabberd2 servers. This corrects an issue parsing one-character or empty elements. (Noa Resare) (#a14514)
Yahoo!/Yahoo! JAPAN:
Fix a crash when an account disconnects before a p2p session is completely set up. (Jan Kaluza) (#12432)

General:
Our bundled libgadu should now build on HP-UX.
Fix some instances of file transfers never completing. (Cristi Posoiu) (#12472)

Pidgin:
Sort by Status no longer causes buddies to move around when you click them.
Fix embedding in the system tray on older GTK+ releases (such as on CentOS 5.5 and older Fedora).
No longer require libstartup-notification for startup notification support. GTK+ has included support for years, so use it instead. (David Benjamin) (#13245)

AIM:
Fix a bug where some buddies from your buddy list might not show up. Affected non-English ICQ users the most. (#13386)
Send keepalives for all types of network connections. Will hopefully make chat rooms more reliable. (#1449)

MSN:
Fix bug that prevented added buddies to your buddy list in certain circumstances. (#13298)

XMPP:
Fix building on platforms with an older glib (inadvertantly broken in 2.7.10). (#13329)
Don't treat the on-join status storms as 'new arrivals'. (Thijs Alkemade) (#a14527)
Extend the /join command to support room JIDs, enabling you to join a room on any server. (Solarius, Matěj Cepl, Tirtha 'wyuka' Chatterjee) (#4526)
Add support for receiving a limited amount of history when joining a room (not currently supported by Pidgin and Finch). (Thijs Alkemade) (#10986, #a14219)

Yahoo!/Yahoo! JAPAN:
Fix CVE-2011-1091, denials of service caused by NULL pointer dereferences due to improper handling of malformed YMSG packets. Thanks to Marius Wachtler for reporting this and reviewing the fix!

General:
Implement simple silence suppression for voice calls, preventing wasted bandwidth for silent periods during a call. (Jakub Adam) (half of #13180)
Added the DigiCert? High Assurance CA-3 intermediate CA, needed for validation of the Facebook XMPP interface's certificate.
Removed the QQ protocol plugin. It hasn't worked in a long time and isn't being maintained, therefore we no longer want it.

Pidgin:
Duplicate code cleanup. (Gabriel Schulhof) (#10599)
Voice/Video call window adapts correctly to adding or removing streams on the fly. (Jakub Adam) (half of #13535)
Don't cancel an ongoing call when rejecting the addition of a stream to the existing call. (Jakub Adam) (#13537)
Pidgin plugins can now override tab completion and detect clicks on usernames in the chat userlist. (kawaii.neko) (#12599)
Fix the tooltip being destroyed when it is full of information and cover the mouse (dliang) (#10510)

libpurple:
media: Allow obtaining active local and remote candidates. (Jakub Adam) (#11830)
media: Allow getting/setting video capabilities. (Jakub Adam) (half of #13095)
Simple Silence Suppression is optional per-account. (Jakub Adam) (half of #13180)
Fix purple-url-handler being unable to find an account.
media: Allow adding/removing streams on the fly. (Jakub Adam) (half of #13535)
Support new connection states in NetworkManager 0.9. (Dan Williams) (#13505)
When removing a buddy, delete the pounces associated with it. (Kartik Mohta) (#1131)
media: Allow libpurple and plugins to set SDES properties for RTP conferences. (Jakub Adam) (#12981)
proxy: Add new "Tor/Privacy" proxy type that can be used to restrict operations that could leak potentially sensitive data (e.g. DNS queries). (#11110, #13928)
media: Add support for using TCP relaying with TURN (will only work with libnice 0.1.0 and later).

AIM:
Fix setting icons with dimensions greater than 64x64 pixels by scaling them down to at most 64x64. (#12874, #13165)

Gadu-Gadu:
Allow showing your status only to buddies. (Mateusz Piękos) (#13358)
Updated internal libgadu to version 1.10.1. (Robert Matusewicz, Krzysztof Klinikowski) (#13525)
Updated internal libgadu to version 1.11.0. (Tomasz Wasilczyk) (#14248)
Suppress blank messages that happen when receiving inline images. (Tomasz Wasilczyk) (#13554)
Fix sending inline images to remote users, don't crash when trying to send large (> 256kB) images. (Tomasz Wasilczyk) (#13580)
Support typing notifications. (Jan Zachorowski, Tomasz Wasilczyk, Krzysztof Klinikowski) (#13362, #13590)
Require libgadu 1.11.0 to avoid using internal libgadu.
Optional SSL connection support for GNUTLS users (not on Windows yet!). (Tomasz Wasilczyk) (#13613, #13894)
Don't count received messages or statuses when determining whether to send a keepalive packet. (Jan Zachorowski) (#13699)
Fix a crash when receiving images on Windows or an incorrect timestamp in the log when receiving images on Linux. (Tomasz Wasilczyk) (#10268)
Support XML events, resulting in immediate update of other users' buddy icons. (Tomasz Wasilczyk) (#13739)
Accept poorly formatted URLs from other third-party clients in the same manner as the official client. (Tomasz Wasilczyk) (#13886)

ICQ:
Fix setting icons with dimensions greater than 64x64 pixels by scaling them down to at most 64x64. (#12874, #13165)
Fix unsetting your mood when "None" is selected. (Dustin Gathmann) (#11895)
Ignore Daylight Saving Time when performing calculations related to birthdays. (Dustin Gathmann) (#13533)
It is now possible to specify multiple encodings on the Advanced tab of an ICQ account's settings by using a comma-delimited list. (Dmitry Utkin (#13496))

IRC:
Add "authserv" service command. (tomos) (#13337)

MSN:
Fix a hard-to-exploit crash in the MSN protocol when using the HTTP connection method (Reported by Marius Wachtler).

MXit:
Support for an Invite Message when adding a buddy.
Fixed bug in splitting-up of messages that contain a lot of links.
Fixed crash caused by timer not being disabled on disconnect. (introduced in 2.7.11)
Clearing of the conversation window now works.
When receiving an invite you can display the sender's profile information, avatar image, invite message.
The Change PIN option was moved into separate action.
New profile attributes added and shown.
Update to protocol v6.3.
Added the ability to view and invite your Suggested Friends, and to search for contacts.
Also display the Status Message of offline contacts in their profile information.

XMPP:
Remember the previously entered user directory when searching. (Keith Moyer) (#12451)
Correctly handle a buddy's unsetting his/her vCard-based avatar. (Matthew W.S. Bell) (#13370)
Squash one more situation that resulted in duplicate entries in the roster (this one where the server reports the buddy as being in the same (empty) group. (Reported by Danny Mayer)

Plugins:
The Voice/Video Settings plugin now includes the ability to test microphone settings. (Jakub Adam) (#13182)
Fix a crash when handling some saved settings in the Voice/Video Settings plugin. (Pat Erley) (13290, #13774)
Windows-Specific Changes:
Fix building libpurple with Visual C++ .NET 2005. This was accidentally broken in 2.7.11. (Florian Quèze)
Build internal libgadu using packed structs, fixing several long-standing Gadu-Gadu issues. (#11958, #6297)