Tk Source Code

Each time -locale is set on an entry, a spinbox, a text widget or a text tag, widget creation included, one Tcl_Obj is leaked.

SetLocale (TkLocaleOption) replaces *value with a new normalized object. These options have no objOffset, so DoObjConfig keeps no reference to the new object, and nothing frees it. ttk::entry is not affected, because its option has an objOffset.

Measured with a TCL_MEM_DEBUG build of trunk 2d659391fc:

• entry .w; destroy .w: 114 bytes per widget (same for spinbox and text);
• .e configure -locale ab_CD: 118 bytes per call;
• frame .w; destroy .w and ttk::entry .w; destroy .w: 0.

Proposed fix: branch nab-wrap-locale, check-in aef871dbbd. For a custom option, DoObjConfig frees a new value object returned by the setProc when no slot keeps it (Tcl_BounceRefCount). This only acts when the setProc replaces the value with a new object, which only SetLocale does among the custom options of Tk.

New test entry-5.20 (constraint memory): 118 114 before the fix, 0 0 after. config.test, entry.test, spinbox.test and panedwindow.test pass (1295, 0), as do the ttk entry, spinbox and combobox tests (101, 0).

The same check-in is in revised_text b714df6a8a, where [$w brks] with a locale also leaked its argument; that part only concerns revised_text.

Checked on macOS (aqua) only.