Have magic.tcl look for the shared library in the script directory

Rather than having the build process embed an absolute path.
The first of a couple of steps to make the magic build relocatable.

tcltk/Makefile

@@ -63,7 +63,7 @@ magic.tcl: magic.tcl.in ${MAGICDIR}/defs.mak ${MAGICDIR}/VERSION
 	sed -e /TCL_DIR/s%TCL_DIR%${TCLDIR}%g  \
 	    -e /MAGIC_VERSION/s%MAGIC_VERSION%${MAGIC_VERSION}%g \
 	    -e /MAGIC_REVISION/s%MAGIC_REVISION%${MAGIC_REVISION}%g \
-            -e /SHDLIB_EXT/s%SHDLIB_EXT%${SHDLIB_EXT}%g magic.tcl.in > magic.tcl
+	    -e /SHDLIB_EXT/s%SHDLIB_EXT%${SHDLIB_EXT}%g magic.tcl.in > magic.tcl
 
 magic.sh: magic.sh.in ${MAGICDIR}/defs.mak
 	sed -e /TCL_DIR/s%TCL_DIR%${TCLDIR}%g \

tcltk/magic.tcl.in

@@ -1,19 +1,20 @@
 # Wishrc startup for ToolScript (magic)
 #
 # For installation:  Put this file and also magicwrap.so into
-# directory TCL_DIR, and set the "load" line below
-# to point to the location of magicwrap.so.  Also see comments
-# in shell script "magic.sh".
+# the same directory. Also see comments in shell script "magic.sh".
 
 global Opts
-  
+
 # If we called magic via the non-console script, then we want to reset
 # the environment variable HOME to its original value.
-   
+
+variable MAGIC_TCL_DIR [file dirname [file normalize [info script]]]
+variable CAD_ROOT_DEFAULT [file normalize [file join $MAGIC_TCL_DIR ../..]]
+
 if {${tcl_version} >= 8.6} {
-   load -lazy TCL_DIR/tclmagicSHDLIB_EXT
+   load -lazy [file join $MAGIC_TCL_DIR tclmagic[info sharedlibextension]]
 } else {
-   load TCL_DIR/tclmagicSHDLIB_EXT
+   load [file join $MAGIC_TCL_DIR tclmagic[info sharedlibextension]]
 }
 
 # It is important to make sure no magic commands overlap with Tcl built-in
@@ -30,8 +31,8 @@ proc pushnamespace { name } {
    foreach v $y {
       regsub -all {\*} $v {\\*} i
       set x [namespace tail $i]
-      if {[lsearch $z $x] < 0} { 
-         namespace import $i                       
+      if {[lsearch $z $x] < 0} {
+         namespace import $i
       }
    }
 }
@@ -124,7 +125,7 @@ proc xcircuit { args } {
       # execute script in the scope of magic, because its variable space is
       # not modularized.
       set argv $args
-      set argc [llength $args] 
+      set argc [llength $args]
       uplevel #0 source $xcircscript
    }
 }
@@ -143,7 +144,7 @@ proc netgen { args } {
       puts stderr "\"source <path>/netgen.tcl\"."
    } else {
       set argv $args
-      set argc [llength $args] 
+      set argc [llength $args]
       uplevel #0 source $netgenscript
    }
 }
@@ -151,7 +152,7 @@ proc netgen { args } {
 # Add the "echo" command
 
 proc echo {args} {
-   puts stdout $args  
+   puts stdout $args
 }
 
 # Parse argument list for "-c[onsole]" and "-now[rapper]".

tcltk/tclmagic.c

@@ -1224,7 +1224,7 @@ Tclmagic_Init(interp)
     /* Set $CAD_ROOT as a Tcl variable */
 
     cadroot = getenv("CAD_ROOT");
-    if (cadroot == NULL) cadroot = CAD_DIR;
+    if (cadroot == NULL) cadroot = Tcl_GetVar(interp, "CAD_ROOT_DEFAULT", TCL_GLOBAL_ONLY);
 
     Tcl_SetVar(interp, "CAD_ROOT", cadroot, TCL_GLOBAL_ONLY);