Update docs regarding tilde substitution (backported from 9.0). For T…

…CLLIBPATH, do the same tilde substitution as done for TCLx.y_TM_PATH (backported from 9.0 too)

doc/tclvars.n

@@ -31,6 +31,10 @@ the parent directory of \fBtcl_library\fR,
 the directories listed in the \fBtcl_pkgPath\fR variable.
 Additional locations to look for files and package indices should
 normally be added to this variable using \fBlappend\fR.
+Initialization of auto_path from the TCLLIBPATH environment
+variable undergoes tilde substitution (see \fBfilename\fR) on each
+path. Any tilde substitution that fails because the user is unknown
+will be omitted from auto_path.
 .RS
 .PP
 Additional variables relating to package management exist. More

doc/tm.n

@@ -300,6 +300,10 @@ environment variables:
 \fB$::env(TCL8.1_TM_PATH)\fR  \fB$::env(TCL8_1_TM_PATH)\fR
 \fB$::env(TCL8.0_TM_PATH)\fR  \fB$::env(TCL8_0_TM_PATH)\fR
 .CE
+.PP
+Paths initialized from the environment variables undergo tilde
+substitution (see \fBfilename\fR). Any path whose tilde substitution
+fails because the user is unknown will be omitted from search paths.
 .SH "SEE ALSO"
 package(n), Tcl Improvement Proposal #189
 .QW "\fITcl Modules\fR"

library/init.tcl

@@ -43,7 +43,15 @@ package require -exact tcl 8.7b1
 
 if {![info exists auto_path]} {
     if {[info exists env(TCLLIBPATH)] && (![interp issafe])} {
-	set auto_path $env(TCLLIBPATH)
+	set auto_path [apply {{} {
+	    lmap path $::env(TCLLIBPATH) {
+		# Paths relative to unresolvable home dirs are ignored
+		if {[catch {file tildeexpand $path} expanded_path]} {
+		    continue
+		}
+		set expanded_path
+	    }
+	}}]
     } else {
 	set auto_path ""
     }