#1552 Problem with nonexistent namespaces

[Les Cargill]

Platform:

Win98SE,Wish8.3for Windows.

Description:

It is possible to assign the "-textvariable <name>" option
to an entry widget using a namespace that does not
yet exist.

After the namespace and variable are instantiated, changes to
the variable are not reflected within the text widget.

Subsequent ".entry config -textvariable <name> "
commands do not clear up the problem.

Code snippet:
entry .foo -textvariable fred::foo(wha)

namespace eval fred {
variable foo
}

grid .foo

set fred::foo(wha) "Hey!"

[Don Porter]

Logged In: YES
user_id=80530

confirmed in 8.4x and HEAD
Looks like it may really be
a bug in variable traces.

[Don Porter]

Logged In: YES
user_id=80530

It appears that the [entry] code was
written with the assumption that
Tcl_SetVar() always succeeds
in creating a variable, and Tcl_TraceVar
always succeeds in creating a trace.
Those calls do not automatically
create missing namespaces, so they
actually fail when directed to work on
a variable in a namespace that does
not (yet) exist.

The workaround, of course, is to create
namespaces before tying widgets to
them.

An actual fix has to wait until a time
when Tcl might be modified to
create namespaces as they
are needed. See Tcl RFE 582926.
That will not happen in an 8.4.x release.