gitk: Quote tag names in event bindings to avoid problems with % chars

Tag names that contain a % character require quoting when used in event
bindings or the name may be mis-recognised for percent substitution in
the event script.

Reported-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -6301,6 +6301,7 @@ proc drawtags {id x xt y1} {
 	       -width $lthickness -fill black -tags tag.$id]
     $canv lower $t
     foreach tag $marks x $xvals wid $wvals {
+	set tag_quoted [string map {% %%} $tag]
 	set xl [expr {$x + $delta}]
 	set xr [expr {$x + $delta + $wid + $lthickness}]
 	set font mainfont
@@ -6309,7 +6310,7 @@ proc drawtags {id x xt y1} {
 	    set t [$canv create polygon $x [expr {$yt + $delta}] $xl $yt \
 		       $xr $yt $xr $yb $xl $yb $x [expr {$yb - $delta}] \
 		       -width 1 -outline black -fill yellow -tags tag.$id]
-	    $canv bind $t <1> [list showtag $tag 1]
+	    $canv bind $t <1> [list showtag $tag_quoted 1]
 	    set rowtextx([rowofcommit $id]) [expr {$xr + $linespc}]
 	} else {
 	    # draw a head or other ref
@@ -6336,9 +6337,9 @@ proc drawtags {id x xt y1} {
 	set t [$canv create text $xl $y1 -anchor w -text $tag -fill $fgcolor \
 		   -font $font -tags [list tag.$id text]]
 	if {$ntags >= 0} {
-	    $canv bind $t <1> [list showtag $tag 1]
+	    $canv bind $t <1> [list showtag $tag_quoted 1]
 	} elseif {$nheads >= 0} {
-	    $canv bind $t $ctxbut [list headmenu %X %Y $id $tag]
+	    $canv bind $t $ctxbut [list headmenu %X %Y $id $tag_quoted]
 	}
     }
     return $xt