Tcl/Tk 8.6.5 RELEASED

Tcl/Tk 8.6.5 RELEASED


Tcl/Tk 8.6.5 Release Announcement
February 29, 2016

The Tcl Core Team is pleased to announce the 8.6.5 releases of the Tcl dynamic language and the Tk toolkit. This is the fifth patch release of Tcl/Tk 8.6. More details can be found below. We would like to express our gratitude to all those who submit bug reports and patches. This information is invaluable in enabling us to identify and eliminate problems in the core.

Where to get the new releases:

Tcl/Tk 8.6.5 sources are freely available as open source from the Tcl Developer Xchange web site at:


This web page also contains additional information about the releases, including new features and notes about installing and compiling the releases. Sources are always available from the Tcl SourceForge project's file distribution area:


Binaries for most major platforms are available from:


For additional information:

Please visit the Tcl Developer Xchange web site:


This site contains a variety of information about Tcl/Tk in general, thecore Tcl and Tk distributions, Tcl development tools, and much more.

Summary of Changes since Tcl/Tk 8.6.4:

This is a patch release, so it primarily includes bug fixes and correctionsto erratic behavior. All relevant bug fixes (and some more) up to and including 8.5.19 changes are included in 8.6.5. Highlighted changes are noted below. The changes file at the root of the source tree contains a more complete list. The Timelines of all changes are online.


* [TIP 436] [info object isa] favors 'false' over error.
* [TIP 441] New option [listbox ... -justify].
* New Tk icons have clear free license.
* Stopped use of deprecated Cocoa API calls that trigger warnings in clang.
* Cocoa: Smoother window resizing; eliminated redraw/flicker on El Capitan.
* Cocoa: Elimination of zombie windows when windows are closed.
* Fixed crashes or hangs in...
- traced [expr].
- OO teardown.
- [$text delete].
- asynchronous socket connection on Windows.
- large-scale multi-threading with forks.
- overflows and memory errors in image handling.
* Repaired memory leaks in
- compiled [unset a($i)].
- zlib compresion errors.
- [file] operations on Windows.
- Cocoa event loop processing.
* Fix: [tailcall] combinations with [next] or ensembles.
* Fix: compiled [lreplace] handling of end.
* Fix: Ctrl-C/Ctrl-Break in Window console not treated as EOF.
* Fix: [tk_getOpenFile] -initialdir on Windows.
* Fix: streaming [zlib deflate] failure on empty input.
* Fix: non-empty [self] in destructor after failed constructor.
* Updated bundled packages
- msgcat 1.6.0: [TIP 412] dynamic and per-package locale.
- http 2.8.9: Default gzip transfer encoding; per-connection -accept
- registry 1.3.1: Unicode SendMessageTimeout().
- Itcl 4.0.4
- Thread 2.7.3
- sqlite 3.11.0
- TDBC* 1.0.4