Tcl Source Code

In a build of trunk with --enable-symbols and CFLAGS="-DPURIFY", the following script

<blockquote><code><verbatim>
trace add variable one write [list ::apply [list args {
	error {this error}
} [namespace current]]]
set one [lindex [lreplace [lseq 1 2] 1 1 hello] 0]
</verbatim></code></blockquote>

Results in the following error:

<blockquote><code><verbatim>
malloc(): unaligned fastbin chunk detected 3
</verbatim></code></blockquote>

The reason is that <code>lreplace</code> converts the internal repesentation
from <code>tclArithSeriesType</code> to <cod>tclListType</code>, and
<code>SetListFromAny()</code> handles the arithmetic series specially,
forgetting to increment the reference count when each <code>Tcl_Obj</code> is
added to the list.  See
[https://core.tcl-lang.org/tcl/file?udc=1&ln=3323&ci=57e46213e1e5414a&name=generic%2FtclListObj.c|this
loop].

Fixed in [e45cee0c53].