[PATCH] gitk: avoid error on reload

[Michele Ballabio <barra_cuda@katamail.com>]

When hitting "Reload", gitk can error out, complaining
about "wrong # coordinates: expected 0 or 4, got 2".
This patch checks that there are 4 coordinates to avoid this
error:

wrong # coordinates: expected 0 or 4, got 2
wrong # coordinates: expected 0 or 4, got 2
    while executing
".tf.histframe.pwclist.canv create rect -outline {} -tags secsel -fill gray85"
    ("eval" body line 1)
    invoked from within
"eval $canv create rect [$canv bbox $linehtag($l)] -outline {{}}  -tags secsel -fill [$canv cget -selectbackground]"
    (procedure "make_secsel" line 6)
    invoked from within
"make_secsel $l"
    (procedure "selectline" line 62)
    invoked from within
"selectline [rowofcommit $pending_select] 1"
    (procedure "layoutmore" line 12)
    invoked from within
"layoutmore"
    (procedure "chewcommits" line 5)
    invoked from within
"chewcommits"
    ("eval" body line 1)
    invoked from within
"eval $script"
    (procedure "dorunq" line 9)
    invoked from within
"dorunq"
    ("after" script)

Signed-off-by: Michele Ballabio <barra_cuda@katamail.com>
---

I don't know if this patch is the right fix, so here is a script
that triggers this error:

--->8---
#!/bin/sh

rm -rf .git
git init
touch initial
git add initial
git commit initial -m "initial"

git checkout -b m-master

sleep 1
touch one
git add one
git commit one -m "one"
sleep 1
touch two
git add two
git commit two -m "two"
sleep 1
touch three
git add three
git commit three -m "three"

sleep 1
echo "Now reorder the commits as:"
echo "pick three"
echo "pick one"
echo "pick two"
read
git rebase -i master

git checkout -b m-reload master

sleep 1
touch four
git add four
git commit four -m "four"
sleep 1
touch five
git add five
git commit five -m "five"

git checkout m-master

gitk --all
# within gitk, reload: it should give an error.
# if it does not error out, checkout another branch and try
# to reload again.
---8<---

 gitk |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/gitk b/gitk
index 9ab6dba..041345d 100755
--- a/gitk
+++ b/gitk
@@ -5827,7 +5827,8 @@ proc dispnexttag {} {
 proc make_secsel {l} {
     global linehtag linentag linedtag canv canv2 canv3
 
-    if {![info exists linehtag($l)]} return
+    if {![info exists linehtag($l)] ||
+	[llength [$canv bbox $linehtag($l)]] ne 4 } return
     $canv delete secsel
     set t [eval $canv create rect [$canv bbox $linehtag($l)] -outline {{}} \
 	       -tags secsel -fill [$canv cget -selectbackground]]
-- 
1.5.5.1