Docs for Tcl_ParseExpr() claim:
"...Only the token information in the Tcl_Parse structure
is modified: the commentStart, commentSize,
and commandSize fields are not modified by
This is not true, and appears to have
never been true.
In fact, T_PE sets those fields to their
initialized values of NULL and 0 as
There seems to be only one reason for
T_PE to do this, and that is that the
PrintParse() routine in tclTest.c assumes
these fields have valid values and prints
them, so T_PE's initialization of them
avoids disaster. If tclTest.c took care
of its own init needs, then T_PE could be
modified to match its docs.