[PATCH] gitk: refresh the index before running diff-files

[Jeff King <peff@peff.net>]

On Fri, Sep 28, 2012 at 04:23:30PM -0400, Jeff King wrote:

> > I'm trying to figure out what the problem with "git diff-files" is
> > because gitk uses it under the hood, and I think that gitk is
> > reporting  erroneous changes (which are also reset by performing a
> > "git status" in the repo) in the "patch" files list.
> 
> gitk should probably be calling "update-index --refresh" on startup. If
> it already is, then it may be that whatever is updating the files is
> doing it while gitk is running.

Ah, it is not refreshing the index at all.  Try this (substitute
Makefile with some file in your repository):

  $ touch Makefile
  $ gitk  <-- reports uncommitted changes
  $ git update-index --refresh
  $ gitk  <-- changes go away

I am not a tcl hacker, but the patch below seems to fix it for me.

-- >8 --
Subject: [PATCH] gitk: refresh the index before running diff-files

If you have index entries that are stat-dirty but otherwise
unchanged, gitk will erroneously report that "local
uncommited changes" are present. This is because we call the
plumbing diff-files, which expects us to have updated the
index ourselves. So let's start doing so.

We only run this once per invocation of gitk, though. The
point of diff-files not running the update is that it does
not need to be run for every command, but generally only
once per high-level operation.

Signed-off-by: Jeff King <peff@peff.net>
---
Potentially the "reload" command should reset the need_index_refresh
flag, too.

 gitk | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/gitk b/gitk
index 379582a..561be23 100755
--- a/gitk
+++ b/gitk
@@ -5112,6 +5112,14 @@ proc dodiffindex {} {
     filerun $fd [list readdiffindex $fd $lserial $i]
 }
 
+proc refresh_index {} {
+    global need_index_refresh
+    if { $need_index_refresh } {
+	exec sh -c "git update-index --refresh >/dev/null 2>&1 || true"
+	set need_index_refresh false
+    }
+}
+
 proc readdiffindex {fd serial inst} {
     global viewmainheadid nullid nullid2 curview commitinfo commitdata lserial
     global vfilelimit
@@ -5131,6 +5139,7 @@ proc readdiffindex {fd serial inst} {
     }
 
     # now see if there are any local changes not checked in to the index
+    refresh_index
     set cmd "|git diff-files"
     if {$vfilelimit($curview) ne {}} {
 	set cmd [concat $cmd -- $vfilelimit($curview)]
@@ -11670,6 +11679,7 @@ set want_ttk 1
 set autosellen 40
 set perfile_attrs 0
 set want_ttk 1
+set need_index_refresh true
 
 if {[tk windowingsystem] eq "aqua"} {
     set extdifftool "opendiff"
-- 
1.7.12.42.g8bdb6d3