* library/auto.tcl: Updates to the Tcl script library to make

        * library/history.tcl:  use of Tcl 8.4 features.  Forward port of
        * library/init.tcl:     appropriate portions of [Patch 1237755].
        * library/package.tcl:
        * library/safe.tcl:
        * library/word.tcl:

6 files changed, 76 insertions, 78 deletions

diff --git a/library/auto.tcl b/library/auto.tcl
index 94d0628..63260e7 100644
--- a/library/auto.tcl
+++ b/library/auto.tcl
@@ -3,7 +3,7 @@
 # utility procs formerly in init.tcl dealing with auto execution
 # of commands and can be auto loaded themselves.
 #
-# RCS: @(#) $Id: auto.tcl,v 1.26 2005/06/24 23:32:26 dgp Exp $
+# RCS: @(#) $Id: auto.tcl,v 1.27 2005/07/23 04:12:48 dgp Exp $
 #
 # Copyright (c) 1991-1993 The Regents of the University of California.
 # Copyright (c) 1994-1998 Sun Microsystems, Inc.
@@ -62,8 +62,7 @@ proc tcl_findLibrary {basename version patch initScript enVarName varName} {
 
     # The C application may have hardwired a path, which we honor
 
-    set variableSet [info exists the_library]
-    if {$variableSet && $the_library ne ""} {
+    if {[info exists the_library] && $the_library ne ""} {
 	lappend dirs $the_library
     } else {
 
@@ -157,9 +156,7 @@ proc tcl_findLibrary {basename version patch initScript enVarName varName} {
             }
         }
     }
-    if {!$variableSet} {
-	unset the_library
-    }
+    unset -nocomplain the_library
     set msg "Can't find a usable $initScript in the following directories: \n"
     append msg "    $dirs\n\n"
     append msg "$errors\n\n"
@@ -215,7 +212,7 @@ proc auto_mkindex {dir args} {
     }
 
     auto_mkindex_parser::init
-    foreach file [glob {expand}$args] {
+    foreach file [glob -- {expand}$args] {
         if {[catch {auto_mkindex_parser::mkindex $file} msg opts] == 0} {
             append index $msg
         } else {
@@ -248,7 +245,7 @@ proc auto_mkindex_old {dir args} {
     if {[llength $args] == 0} {
 	set args *.tcl
     }
-    foreach file [glob {expand}$args] {
+    foreach file [glob -- {expand}$args] {
 	set f ""
 	set error [catch {
 	    set f [open $file]
@@ -444,11 +441,10 @@ proc auto_mkindex_parser::commandInit {name arglist body} {
 
     set ns [namespace qualifiers $name]
     set tail [namespace tail $name]
-    if {[string equal $ns ""]} {
-        set fakeName "[namespace current]::_%@fake_$tail"
+    if {$ns eq ""} {
+        set fakeName [namespace current]::_%@fake_$tail
     } else {
-	set fakeName [string map {:: _} "_%@fake_$name"]
-        set fakeName "[namespace current]::$fakeName"
+        set fakeName [namespace current]::[string map {:: _} _%@fake_$name]
     }
     proc $fakeName $arglist $body
 
@@ -457,7 +453,7 @@ proc auto_mkindex_parser::commandInit {name arglist body} {
     # we have to build procs with the fully qualified names, and
     # have the procs point to the aliases.
 
-    if {[string match "*::*" $name]} {
+    if {[string match *::* $name]} {
         set exportCmd [list _%@namespace export [namespace tail $name]]
         $parser eval [list _%@namespace eval $ns $exportCmd]
  
@@ -507,7 +503,7 @@ proc auto_mkindex_parser::fullname {name} {
         }
     }
 
-    if {[string equal [namespace qualifiers $name] ""]} {
+    if {[namespace qualifiers $name] eq ""} {
         set name [namespace tail $name]
     } elseif {![string match ::* $name]} {
         set name "::$name"
@@ -551,7 +547,7 @@ auto_mkindex_parser::command proc {name args} {
 
 auto_mkindex_parser::hook {
     if {![catch {package require tbcload}]} {
-	if {[llength [info commands tbcload::bcproc]] == 0} {
+	if {[namespace which -command tbcload::bcproc] eq ""} {
 	    auto_load tbcload::bcproc
 	}
 	load {} tbcload $auto_mkindex_parser::parser
@@ -602,7 +598,7 @@ auto_mkindex_parser::command namespace {op args} {
             variable parser
             variable imports
             foreach pattern $args {
-                if {[string compare $pattern "-force"]} {
+                if {$pattern ne "-force"} {
                     lappend imports $pattern
                 }
             }
diff --git a/library/history.tcl b/library/history.tcl
index 7304d2a..3a3f16a 100644
--- a/library/history.tcl
+++ b/library/history.tcl
@@ -2,7 +2,7 @@
 #
 # Implementation of the history command.
 #
-# RCS: @(#) $Id: history.tcl,v 1.6 2003/03/19 21:57:42 dgp Exp $
+# RCS: @(#) $Id: history.tcl,v 1.7 2005/07/23 04:12:49 dgp Exp $
 #
 # Copyright (c) 1997 Sun Microsystems, Inc.
 #
@@ -168,14 +168,14 @@ proc history {args} {
     variable history
 
     # Do not add empty commands to the history
-    if {[string trim $command] == ""} {
+    if {[string trim $command] eq ""} {
 	return ""
     }
 
     set i [incr history(nextid)]
     set history($i) $command
     set j [incr history(oldest)]
-    if {[info exists history($j)]} {unset history($j)}
+    unset -nocomplain history($j)
     if {[string match e* $exec]} {
 	return [uplevel #0 $command]
     } else {
@@ -198,13 +198,13 @@ proc history {args} {
 
  proc tcl::HistKeep {{limit {}}} {
     variable history
-    if {[string length $limit] == 0} {
+    if {$limit eq ""} {
 	return $history(keep)
     } else {
 	set oldold $history(oldest)
 	set history(oldest) [expr {$history(nextid) - $limit}]
 	for {} {$oldold <= $history(oldest)} {incr oldold} {
-	    if {[info exists history($oldold)]} {unset history($oldold)}
+	    unset -nocomplain history($oldold)
 	}
 	set history(keep) $limit
     }
@@ -246,7 +246,7 @@ proc history {args} {
 
  proc tcl::HistInfo {{num {}}} {
     variable history
-    if {$num == {}} {
+    if {$num eq ""} {
 	set num [expr {$history(keep) + 1}]
     }
     set result {}
@@ -280,7 +280,7 @@ proc history {args} {
 
  proc tcl::HistRedo {{event -1}} {
     variable history
-    if {[string length $event] == 0} {
+    if {$event eq ""} {
 	set event -1
     }
     set i [HistIndex $event]
diff --git a/library/init.tcl b/library/init.tcl
index d93a653..e1f4b05 100644
--- a/library/init.tcl
+++ b/library/init.tcl
@@ -3,7 +3,7 @@
 # Default system startup file for Tcl-based applications.  Defines
 # "unknown" procedure and auto-load facilities.
 #
-# RCS: @(#) $Id: init.tcl,v 1.77 2005/06/06 23:45:46 dkf Exp $
+# RCS: @(#) $Id: init.tcl,v 1.78 2005/07/23 04:12:49 dgp Exp $
 #
 # Copyright (c) 1991-1993 The Regents of the University of California.
 # Copyright (c) 1994-1996 Sun Microsystems, Inc.
@@ -114,9 +114,9 @@ if {(![interp issafe]) && ($tcl_platform(platform) eq "windows")} {
 			    if {![info exists env($u)]} {
 				set env($u) $env($p)
 			    }
-			    trace variable env($p) w \
+			    trace add variable env($p) write \
 				    [namespace code [list EnvTraceProc $p]]
-			    trace variable env($u) w \
+			    trace add variable env($u) write \
 				    [namespace code [list EnvTraceProc $p]]
 			}
 		    }
@@ -177,7 +177,7 @@ if {[interp issafe]} {
 
 # Conditionalize for presence of exec.
 
-if {[llength [info commands exec]] == 0} {
+if {[namespace which -command exec] eq ""} {
 
     # Some machines do not have exec. Also, on all
     # platforms, safe interpreters do not have exec.
@@ -188,7 +188,7 @@ if {[llength [info commands exec]] == 0} {
 # Define a log command (which can be overwitten to log errors
 # differently, specially when stderr is not available)
 
-if {[llength [info commands tclLog]] == 0} {
+if {[namespace which -command tclLog] eq ""} {
     proc tclLog {string} {
 	catch {puts stderr $string}
     }
@@ -235,7 +235,7 @@ proc unknown args {
 
     catch {set savedErrorInfo $::errorInfo}
     catch {set savedErrorCode $::errorCode}
-    set name [lindex $args 0]
+    set name $cmd
     if {![info exists auto_noload]} {
 	#
 	# Make sure we're not trying to load the same proc twice.
@@ -323,9 +323,9 @@ proc unknown args {
 	    && [info exists tcl_interactive] && $tcl_interactive} {
 	if {![info exists auto_noexec]} {
 	    set new [auto_execok $name]
-	    if {$new != ""} {
+	    if {$new ne ""} {
 		set redir ""
-		if {[info commands console] eq ""} {
+		if {[namespace which -command console] eq ""} {
 		    set redir ">&@stdout <@stdin"
 		}
 		return [uplevel 1 exec $redir $new [lrange $args 1 end]]
@@ -333,9 +333,9 @@ proc unknown args {
 	}
 	if {$name eq "!!"} {
 	    set newcmd [history event]
-	} elseif {[regexp {^!(.+)$} $name dummy event]} {
+	} elseif {[regexp {^!(.+)$} $name -> event]} {
 	    set newcmd [history event $event]
-	} elseif {[regexp {^\^([^^]*)\^([^^]*)\^?$} $name dummy old new]} {
+	} elseif {[regexp {^\^([^^]*)\^([^^]*)\^?$} $name -> old new]} {
 	    set newcmd [history event -1]
 	    catch {regsub -all -- $old $newcmd $new newcmd}
 	}
@@ -354,11 +354,19 @@ proc unknown args {
 		    "\n    (expanding command prefix \"$name\" in unknown)"
 	    return -options $opts $msg
 	}
+	# Handle empty $name separately due to strangeness in [string first]
+	if {$name eq ""} {
+	    if {[llength $candidates] != 1} {
+		return -code error "empty command name \"\""
+	    }
+	    # It's not really possible to reach here.
+	    return [uplevel 1 [lreplace $args 0 0 [lindex $candidates 0]]]
+	}
 	# Filter out bogus matches when $name contained
 	# a glob-special char [Bug 946952]
 	set cmds [list]
 	foreach x $candidates {
-	    if {[string range $x 0 [expr [string length $name]-1]] eq $name} {
+	    if {[string first $name $x] == 0} {
 		lappend cmds $x
 	    }
 	}
@@ -366,12 +374,7 @@ proc unknown args {
 	    return [uplevel 1 [lreplace $args 0 0 [lindex $cmds 0]]]
 	}
 	if {[llength $cmds]} {
-	    if {$name eq ""} {
-		return -code error "empty command name \"\""
-	    } else {
-		return -code error \
-			"ambiguous command name \"$name\": [lsort $cmds]"
-	    }
+	    return -code error "ambiguous command name \"$name\": [lsort $cmds]"
 	}
     }
     return -code error "invalid command name \"$name\""
@@ -392,7 +395,7 @@ proc unknown args {
 proc auto_load {cmd {namespace {}}} {
     global auto_index auto_path
 
-    if {[string length $namespace] == 0} {
+    if {$namespace eq ""} {
 	set namespace [uplevel 1 [list ::namespace current]]
     }
     set nameList [auto_qualify $cmd $namespace]
@@ -480,7 +483,7 @@ proc auto_load_index {} {
 		    error "[file join $dir tclIndex] isn't a proper Tcl index file"
 		}
 	    } msg opts]
-	    if {$f != ""} {
+	    if {$f ne ""} {
 		close $f
 	    }
 	    if {$error} {
@@ -519,13 +522,13 @@ proc auto_qualify {cmd namespace} {
     # with the following form :
     # ( inputCmd, inputNameSpace) -> output
 
-    if {[regexp {^::(.*)$} $cmd x tail]} {
+    if {[string match ::* $cmd]} {
 	if {$n > 1} {
 	    # ( ::foo::bar , * ) -> ::foo::bar
 	    return [list $cmd]
 	} else {
 	    # ( ::global , * ) -> global
-	    return [list $tail]
+	    return [list [string range $cmd 2 end]]
 	}
     }
     
@@ -735,7 +738,7 @@ proc tcl::CopyDirectory {action src dest} {
 	}
     }
     if {[file exists $dest]} {
-	if {$nsrc == $ndest} {
+	if {$nsrc eq $ndest} {
 	    return -code error "error $action \"$src\" to\
 	      \"$dest\": trying to rename a volume or move a directory\
 	      into itself"
@@ -755,10 +758,10 @@ proc tcl::CopyDirectory {action src dest} {
 	    # can be returned in various combinations.  Anyway,
 	    # if any other file is returned, we must signal an error.
 	    set existing [glob -nocomplain -directory $dest * .*]
-	    eval [list lappend existing] \
-	      [glob -nocomplain -directory $dest -type hidden * .*]
+	    lappend existing {expand}[glob -nocomplain -directory $dest \
+		    -type hidden * .*]
 	    foreach s $existing {
-		if {([file tail $s] != ".") && ([file tail $s] != "..")} {
+		if {([file tail $s] ne ".") && ([file tail $s] ne "..")} {
 		    return -code error "error $action \"$src\" to\
 		      \"$dest\": file already exists"
 		}
@@ -768,7 +771,7 @@ proc tcl::CopyDirectory {action src dest} {
 	if {[string first $nsrc $ndest] != -1} {
 	    set srclen [expr {[llength [file split $nsrc]] -1}]
 	    set ndest [lindex [file split $ndest] $srclen]
-	    if {$ndest == [file tail $nsrc]} {
+	    if {$ndest eq [file tail $nsrc]} {
 		return -code error "error $action \"$src\" to\
 		  \"$dest\": trying to rename a volume or move a directory\
 		  into itself"
@@ -786,7 +789,7 @@ proc tcl::CopyDirectory {action src dest} {
       [glob -nocomplain -directory $src -types hidden *]]
 
     foreach s [lsort -unique $filelist] {
-	if {([file tail $s] != ".") && ([file tail $s] != "..")} {
+	if {([file tail $s] ne ".") && ([file tail $s] ne "..")} {
 	    file copy -force $s [file join $dest [file tail $s]]
 	}
     }
diff --git a/library/package.tcl b/library/package.tcl
index 7c4e4e9..9d9e0a9 100644
--- a/library/package.tcl
+++ b/library/package.tcl
@@ -3,7 +3,7 @@
 # utility procs formerly in init.tcl which can be loaded on demand
 # for package management.
 #
-# RCS: @(#) $Id: package.tcl,v 1.32 2004/08/02 22:01:38 dgp Exp $
+# RCS: @(#) $Id: package.tcl,v 1.33 2005/07/23 04:12:49 dgp Exp $
 #
 # Copyright (c) 1991-1993 The Regents of the University of California.
 # Copyright (c) 1994-1998 Sun Microsystems, Inc.
@@ -31,8 +31,8 @@ namespace eval tcl::Pkg {}
 
 proc tcl::Pkg::CompareExtension { fileName {ext {}} } {
     global tcl_platform
-    if {![string length $ext]} {set ext [info sharedlibextension]}
-    if {[string equal $tcl_platform(platform) "windows"]} {
+    if {$ext eq ""} {set ext [info sharedlibextension]}
+    if {$tcl_platform(platform) eq "windows"} {
         return [string equal -nocase [file extension $fileName] $ext]
     } else {
         # Some unices add trailing numbers after the .so, so
@@ -40,7 +40,7 @@ proc tcl::Pkg::CompareExtension { fileName {ext {}} } {
         set root $fileName
         while {1} {
             set currExt [file extension $root]
-            if {[string equal $currExt $ext]} {
+            if {$currExt eq $ext} {
                 return 1
             } 
 
@@ -135,7 +135,7 @@ proc pkg_mkIndex {args} {
     }
 
     if {[catch {
-	    glob -directory $dir -tails -types {r f} {expand}$patternList
+	    glob -directory $dir -tails -types {r f} -- {expand}$patternList
     } fileList o]} {
 	return -options $o $fileList
     }
@@ -145,7 +145,7 @@ proc pkg_mkIndex {args} {
 	# interpreter, and get a list of the new commands and packages
 	# that are defined.
 
-	if {[string equal $file pkgIndex.tcl]} {
+	if {$file eq "pkgIndex.tcl"} {
 	    continue
 	}
 
@@ -154,7 +154,7 @@ proc pkg_mkIndex {args} {
 	# Load into the child any packages currently loaded in the parent
 	# interpreter that match the -load pattern.
 
-	if {[string length $loadPat]} {
+	if {$loadPat ne ""} {
 	    if {$doVerbose} {
 		tclLog "currently loaded packages: '[info loaded]'"
 		tclLog "trying to load all packages matching $loadPat"
@@ -180,7 +180,7 @@ proc pkg_mkIndex {args} {
 	    } elseif {$doVerbose} {
 		tclLog "loaded [lindex $pkg 0] [lindex $pkg 1]"
 	    }
-	    if {[string equal [lindex $pkg 1] "Tk"]} {
+	    if {[lindex $pkg 1] eq "Tk"} {
 		# Withdraw . if Tk was loaded, to avoid showing a window.
 		$c eval [list wm withdraw .]
 	    }
@@ -263,7 +263,7 @@ proc pkg_mkIndex {args} {
 		    set ::tcl::namespaces($::tcl::x) 1
 		}
 		foreach ::tcl::x [package names] {
-		    if {[string compare [package provide $::tcl::x] ""]} {
+		    if {[package provide $::tcl::x] ne ""} {
 			set ::tcl::packages($::tcl::x) 1
 		    }
 		}
@@ -311,7 +311,7 @@ proc pkg_mkIndex {args} {
 			    set ::tcl::newCmds($::tcl::x) 1
 			}
 			foreach ::tcl::x $::tcl::origCmds {
-			    catch {unset ::tcl::newCmds($::tcl::x)}
+			    unset -nocomplain ::tcl::newCmds($::tcl::x)
 			}
 			foreach ::tcl::x [array names ::tcl::newCmds] {
 			    # determine which namespace a command comes from
@@ -324,7 +324,7 @@ proc pkg_mkIndex {args} {
 			    set ::tcl::abs \
 				    [lindex [auto_qualify $::tcl::abs ::] 0]
 			    
-			    if {[string compare $::tcl::x $::tcl::abs]} {
+			    if {$::tcl::x ne $::tcl::abs} {
 				# Name changed during qualification
 				
 				set ::tcl::newCmds($::tcl::abs) 1
@@ -338,7 +338,7 @@ proc pkg_mkIndex {args} {
 		# a version provided, then record it
 
 		foreach ::tcl::x [package names] {
-		    if {[string compare [package provide $::tcl::x] ""] \
+		    if {[package provide $::tcl::x] ne ""
 			    && ![info exists ::tcl::packages($::tcl::x)]} {
 			lappend ::tcl::newPkgs \
 			    [list $::tcl::x [package provide $::tcl::x]]
@@ -437,7 +437,7 @@ proc tclPkgSetup {dir pkg version files} {
 	set f [lindex $fileInfo 0]
 	set type [lindex $fileInfo 1]
 	foreach cmd [lindex $fileInfo 2] {
-	    if {[string equal $type "load"]} {
+	    if {$type eq "load"} {
 		set auto_index($cmd) [list load [file join $dir $f] $pkg]
 	    } else {
 		set auto_index($cmd) [list source [file join $dir $f]]
diff --git a/library/safe.tcl b/library/safe.tcl
index 60687bf..61246e8 100644
--- a/library/safe.tcl
+++ b/library/safe.tcl
@@ -12,7 +12,7 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: safe.tcl,v 1.14 2004/06/29 09:34:44 dkf Exp $
+# RCS: @(#) $Id: safe.tcl,v 1.15 2005/07/23 04:12:49 dgp Exp $
 
 #
 # The implementation is based on namespaces. These naming conventions
@@ -77,7 +77,7 @@ namespace eval ::safe {
 	    upvar $v $v
 	}
 	set flag [::tcl::OptProcArgGiven -noStatics];
-	if {$flag && ($noStatics == $statics) 
+	if {$flag && (!$noStatics == !$statics) 
 	          && ([::tcl::OptProcArgGiven -statics])} {
 	    return -code error\
 		    "conflicting values given for -statics and -noStatics"
@@ -98,7 +98,7 @@ namespace eval ::safe {
 	set flag [::tcl::OptProcArgGiven -nestedLoadOk];
 	# note that the test here is the opposite of the "InterpStatics"
 	# one (it is not -noNested... because of the wanted default value)
-	if {$flag && ($nestedLoadOk != $nested) 
+	if {$flag && (!$nestedLoadOk != !$nested) 
 	          && ([::tcl::OptProcArgGiven -nested])} {
 	    return -code error\
 		    "conflicting values given for -nested and -nestedLoadOk"
@@ -324,7 +324,7 @@ namespace eval ::safe {
 	    nestedok deletehook} {
 
 	# determine and store the access path if empty
-	if {[string equal "" $access_path]} {
+	if {$access_path eq ""} {
 	    set access_path [uplevel \#0 set auto_path]
 	    # Make sure that tcl_library is in auto_path
 	    # and at the first position (needed by setAccessPath)
@@ -764,7 +764,7 @@ proc ::safe::setLogCmd {args} {
 	# Determine where to load. load use a relative interp path
 	# and {} means self, so we can directly and safely use passed arg.
 	set target [lindex $args 1]
-	if {[string length $target]} {
+	if {$target ne ""} {
 	    # we will try to load into a sub sub interp
 	    # check that we want to authorize that.
 	    if {![NestedOk $slave]} {
@@ -776,9 +776,9 @@ proc ::safe::setLogCmd {args} {
 	}
 
 	# Determine what kind of load is requested
-	if {[string length $file] == 0} {
+	if {$file eq ""} {
 	    # static package loading
-	    if {[string length $package] == 0} {
+	    if {$package eq ""} {
 		set msg "load error: empty filename and no package name"
 		Log $slave $msg
 		return -code error $msg
@@ -846,7 +846,7 @@ proc ::safe::setLogCmd {args} {
     proc Subset {slave command okpat args} {
 	set subcommand [lindex $args 0]
 	if {[regexp $okpat $subcommand]} {
-	    return [$command $subcommand {expand}[lrange $args 1 end]]
+	    return [$command {expand}$args]
 	}
 	set msg "not allowed to invoke subcommand $subcommand of $command"
 	Log $slave $msg
@@ -881,11 +881,10 @@ proc ::safe::setLogCmd {args} {
 	set subcommand [lindex $args 0]
 
 	if {[regexp $okpat $subcommand]} {
-	    return [::interp invokehidden $slave encoding $subcommand \
-		    {expand}[lrange $args 1 end]]
+	    return [::interp invokehidden $slave encoding {expand}$args]
 	}
 
-	if {[string match $subcommand system]} {
+	if {[string first $subcommand system] == 0} {
 	    if {$argc == 1} {
 		# passed all the tests , lets source it:
 		if {[catch {::interp invokehidden \
diff --git a/library/word.tcl b/library/word.tcl
index edcb93a..05c3bab 100644
--- a/library/word.tcl
+++ b/library/word.tcl
@@ -10,12 +10,12 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 # 
-# RCS: @(#) $Id: word.tcl,v 1.7 2002/11/01 00:28:51 andreas_kupries Exp $
+# RCS: @(#) $Id: word.tcl,v 1.8 2005/07/23 04:12:49 dgp Exp $
 
 # The following variables are used to determine which characters are
 # interpreted as white space.  
 
-if {[string equal $::tcl_platform(platform) "windows"]} {
+if {$::tcl_platform(platform) eq "windows"} {
     # Windows style - any but a unicode space char
     set tcl_wordchars "\\S"
     set tcl_nonwordchars "\\s"
@@ -58,7 +58,7 @@ proc tcl_wordBreakAfter {str start} {
 
 proc tcl_wordBreakBefore {str start} {
     global tcl_nonwordchars tcl_wordchars
-    if {[string equal $start end]} {
+    if {$start eq "end"} {
 	set start [string length $str]
     }
     if {[regexp -indices "^.*($tcl_wordchars$tcl_nonwordchars|$tcl_nonwordchars$tcl_wordchars)" [string range $str 0 $start] result]} {
@@ -120,7 +120,7 @@ proc tcl_startOfNextWord {str start} {
 
 proc tcl_startOfPreviousWord {str start} {
     global tcl_nonwordchars tcl_wordchars
-    if {[string equal $start end]} {
+    if {$start eq "end"} {
 	set start [string length $str]
     }
     if {[regexp -indices \