From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cristian Tibirna <tibirna@kde.org>
Subject: git diff-tree -r -C output inexact sometimes
Date: Thu, 20 Sep 2012 23:20:31 -0400
Organization: KDE
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Hello

A colleague of mine discovered an inconsistency in the functioning of 

git diff-tree -r -C

in specific conditions. As tenuous as these conditions might seem (once you 
run the script in attachment and analyse its output), please rest assured that 
it comes from a real-life case.

Running the script in attachment produces a git repository in which were 
operated a large number of file renames, in which many of the renamed files 
(in this particular case all) have the same content but different names.

The commit data from the renaming operation (last commit in the script-
generated history) is inexactly rendered by the command 

git diff-tree -r -C master

The logical result is correctly produced by the more restricted command

git diff-tree -r -M master

IMO for this particular last commit both the above commands should return the 
same result.

Note that reducing i or j in the generator script attached below makes the bug 
dissapear.

Thanks a lot for your attention.

-- 
Cristian Tibirna
KDE developer .. tibirna@kde.org .. http://www.kde.org

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Content-Disposition: attachment; filename="generate_git_tree.sh"
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Content-Type: application/x-shellscript; name="generate_git_tree.sh"

#!/bin/bash
mkdir depot
cd depot
for i in {1..1}
do
   mkdir $i
   cd $i
   for j in {1..4}
   do
     mkdir $j
     cd $j
     for k in {1..15}
     do
       touch "my_filename${k}_-2.txt"
     done
     cd ..
   done
   cd ..
done
cd depot
git init
git add .
git commit -m "1st commit"
rename -- '_-2' '-2' */*/*_-2.txt
git add -A
git commit -m "BUG => some files deleted, other copied, but all should be renamed!"

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