Changes in Tcl/Tk 8.6.17

Released August 15, 2025.

Tcl Changes

  • Win: exec now dispatches App Execution Aliases
  • Win: auto_execok recognizes more shell commands
  • encoding cp864: missing Euro/Tail-sign
  • Fix crashes or hangs or undefined behavior in...
    • Tcl_SplitList on string that exceeds max list size
    • Win: Use-after-free memory corruption in multi-thread glob
    • macOs: Pointer alignment in file attribute functions
  • Correct failure in 'namespace children $ns $nonGlob'
  • Number parsing failure: 'scan "1.[string repeat 1 191\]e-321" %g'
  • Nested return -options, cmdMZ-return-2.{19,20,21}
  • errorline into errorinfo from '$interp eval $script', interp-26.9

Tk Changes

  • Win: support PNG images in icon files.
  • Aqua: dark mode improvements.
  • Aqua: interop with clipboard managers.
  • Corrections to zh_cn message catalog for Tk console menu
  • Fix crashes or hangs or undefined behavior in...
    • Aqua: tk_getOpenFile
    • div by zero in [$scale get $x $y\] when trough resized to invisibility
  • block cursor size on a tab is too large.
  • Win: incorrect system menu entries for transient toplevels
  • Win: withdrawn transient windows can reappear in taskbar preview
  • Win: misplaced underline in menu entry
  • Aqua: cannot iconify all windows
  • Aqua: wm-iconbitmap-{1.4,2.1}, uniwWm-22.3

Changes to Bundled Packages

Updated packages, libraries, standards, data

  • Itcl 4.3.4
  • sqlite3 3.50.4
  • Thread 2.8.12
  • DBC* 1.1.12
  • tcltest 2.5.10
  • dde 1.4.5
  • tzdata 2025b