git difftool with symlink to readonly jar failed

From: Etienne d'Hautefeuille <sagoum.kakoum@gmail.com>
Date: May 24, 2018, 21:11 UTC
Message-ID: <CAFazEUP5QJ+WzTkDK6qcgvW5Xwx79KYJWeb1vg41=pS8E8vypQ@mail.gmail.com>

Hi,

In my repo, I have some symlink to readonly jar, I can't make difftool between 2 commit

Steps to reproduce :

> git --version

     git version 2.17.0

> id

uid=1000(sagoum) gid=1000(sagoum) groupes=1000(sagoum),5(tty),10(wheel),14(uucp),18(audio),20(dialout),27(video),35(games),78(kvm),85(usb),100(users),104(plugdev),992(android),993(docker),997(vboxusers)

# readonly jar

> ls -l /home/tempogit/jenkins_war

total 510012 -rwxr----- 1 root users 74585998 24 mai 21:08 jenkins-2.110.war -rwxr----- 1 root users 74612387 24 mai 21:08 jenkins-2.114.war -rwxr----- 1 root users 74606954 24 mai 21:08 jenkins-2.116.war -rwxr----- 1 root users 74737297 24 mai 21:08 jenkins-2.121.war -rwxr----- 1 root users 74525235 24 mai 21:08 jenkins-LTS-2.107.1.war -rwxr----- 1 root users 74568464 24 mai 21:08 jenkins-LTS-2.107.2.war -rwxr----- 1 root users 74576216 24 mai 21:08 jenkins-LTS-2.107.3.war

#create a repo with symlink to this jar

mkdir ~/tempo_2.17.0 cd ~/tempo_2.17.0 git init ln -s /home/tempogit/jenkins_war/jenkins-2.110.war jenkins.war git add jenkins.war git commit -a -m " add symlink on jenkins-2.110.war"

rm jenkins.war ln -s /home/tempogit/jenkins_war/jenkins-2.114.war jenkins.war git add jenkins.war git commit -a -m " add symlink on jenkins-2.114.war"

rm jenkins.war ln -s /home/tempogit/jenkins_war/jenkins-2.116.war jenkins.war git add jenkins.war git commit -a -m " add symlink on jenkins-2.116.war"

#detail of the repo
git log
commit ac1bc44d899ffd5406a7b0c413cf6c2e3497d496 (HEAD -> master)
Author: kakoum <sagoum.kakoum@gmail.com>
Date:   Thu May 24 22:47:09 2018 +0200

      add symlink on jenkins-2.116.war

commit 0244799661b993b1f78fa5afb621de3fe4c4a39c
Author: kakoum <sagoum.kakoum@gmail.com>
Date:   Thu May 24 22:47:09 2018 +0200

      add symlink on jenkins-2.114.war

commit 4cb98b4a307ce97d9e6b8e4b03211fa5ca8af7e7
Author: kakoum <sagoum.kakoum@gmail.com>
Date:   Thu May 24 22:47:09 2018 +0200

      add symlink on jenkins-2.110.war

#try a diff git difftool --dir-diff 4cb98b4a307ce97d9e6b8e4b03211fa5ca8af7e7 0244799661b993b1f78fa5afb621de3fe4c4a39c fatal: impossible d'ouvrir '/tmp/git-difftool.UQ4mqo/left/jenkins.war' en écriture: Permission non accordée

#temporary file
  find /tmp/git-difftool.UQ4mqo/ -ls
    412444      0 drwx------   4  sagoum sagoum       80 mai 24 22:48
/tmp/git-difftool.UQ4mqo/
    412446      0 drwx------   2  sagoum sagoum       40 mai 24 22:48
/tmp/git-difftool.UQ4mqo/right
    412445      0 drwx------   2  sagoum sagoum       60 mai 24 22:48
/tmp/git-difftool.UQ4mqo/left
    412449      0 lrwxrwxrwx   1  sagoum sagoum       44 mai 24 22:48
/tmp/git-difftool.UQ4mqo/left/jenkins.war ->
/home/tempogit/jenkins_war/jenkins-2.110.war

# I have no problem to launch a bcompare between /tmp/git-difftool.UQ4mqo/left and /tmp/git-difftool.UQ4mqo/right (which is empty)

Thank