once again about host-side configure

[Sergei Gavrikov <sg at belvok dot com>]

Hello

At first, nobody won't run in a problem if he/she uses legal Tcl/Tk
packages from his/her distro, i.e. when Tcl/Tk was installed with /usr
prefix. So, all described the below is a rare condition, therefore, it
is a minor issue.

If he/she uses a handy installed Tcl/Tk, I use in example a prefix:
/opt/tcltk/8.5, it's normal to keep the different Tcl versions
separately, he/she can notice that eCos host tools won't be linked with
tk8.5, as he/she could expect, it will be linked with the distro's Tk
library (usually it is /usr/lib/libtk8.4.so).

Demo sniplet

.../configure --with-tcl=/opt/tcltk/8.5 --with-tk=/opt/tcltk/8.5
...
checking for Tcl/Tk installation... 
configure: looking for tclConfig.sh in /opt/tcltk/8.5/lib /usr/local/lib /usr/lib
configure: found /opt/tcltk/8.5/lib/tclConfig.sh
configure: trying TCL_INCLUDE_SPEC - looking for tcl.h in -I/opt/tcltk/8.5/include
configure: using -I/opt/tcltk/8.5/include
configure: using TCL_LIB_SPEC -L/opt/tcltk/8.5/lib -ltcl8.5
configure: using additional libraries for Tcl -ldl  -lpthread -lieee -lm
configure: using additional linker flags for Tcl  -Wl,--export-dynamic 
configure: looking for tkConfig.sh in /opt/tktk/8.5/lib /usr/local/lib /usr/lib
configure: found /usr/lib/tkConfig.sh
configure: trying TK_INCLUDE_SPEC - looking for tk.h in -I/usr/include
configure: using -I/usr/include
configure: trying TK_LIB_SPEC -L/usr/lib -ltk8.4
configure: using -L/usr/lib -ltk8.4
configure: using additional libraries for Tk -lX11 
checking for Tcl/Tk installation... done
...

For a reference (vi +589 acsupport/acinclude.m4):

    possibles=`echo ${possibles} | sed -e 's,tcl,tk,g'`


At first, I thinked to fix sed's substitution, i.e. to use something
like 's,<tcl>,tk,g', but if I used /opt/tcl/8.5 prefix? Then it seems
for me that a better way is just do not check possibles, when Tk prefix
was set exactly with a configure option.

If you can see, we won't run in problem with /opt/TclTk/8.5 prefix. And
I have ActiveState's Tcl/Tk 8.5 installed in /opt/ActiveTcl-8.5. So,
it's possible, the described issue here is a forced issue.

Bart, What do you think about?

Thanks
    Sergei