Re: [BUG] Hang when I did something a bit weird with submodules

> Hi,
>
> I was just setting up a new project using submodules and have run into
> what appears to be a hang when git status is invoked. I haven't tried
> to reproduce this but this is basically what I did (edited highlights
> from my bash_history).
>
>  $ git --version
>  git version 2.0.3
>  $ mkdir proj
>  $ cd proj
>  $ git init
>  $ git submodule add <internal-repo-with-build-scripts> build
>  $ git submodule add --reference ~/src/linux/.git
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux
>  # I'm not sure if the --reference is relevant but I was just wanting
> to cut down on my network transfer
>  $ git submodule add <internal-repo-with-skeleton-fs> rootfs
>
> Oops I really wanted linux-stable to get the same version my board
> vendor is using
>
>  $ vim .gitmodules
>  # change to linux-stable
>  $ git submodule sync
>
> I'm not sure if this is a valid use-case but nothing complained that I
> was changing the URL. In theory linux-stable should be a super-set of
> linus' tree so the repositories are basically equivalent.
>
>  $ cd linux/
>  $ git remote show origin
>  * remote origin
>    Fetch URL: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
>  # Seems to have done the trick
>  $ git reset --hard v3.4.69
>
> I suspect this is where the problem starts. When I did the git
> submodule add it was pointing at the tip of linus' tree. Now I have
> rewound considerably.
>
>  $ git status
>  [hang]
>
> For what it's worth here's the output when I run with GIT_TRACE=1 git status
>
> trace: built-in: git 'status'
> trace: run_command: 'status' '--porcelain'
> trace: exec: 'git' 'status' '--porcelain'
> trace: built-in: git 'status' '--porcelain'
> trace: run_command: 'status' '--porcelain'
> trace: exec: 'git' 'status' '--porcelain'
> trace: built-in: git 'status' '--porcelain'
> trace: run_command: 'status' '--porcelain'
> trace: exec: 'git' 'status' '--porcelain'
> trace: built-in: git 'status' '--porcelain'
> On branch master
>
> Initial commit
>
> Changes to be committed:
>   (use "git rm --cached <file>..." to unstage)
>
>         new file:   .gitmodules
>         new file:   rootfs
>         new file:   build
>         new file:   linux
>
> Changes not staged for commit:
>   (use "git add <file>..." to update what will be committed)
>   (use "git checkout -- <file>..." to discard changes in working directory)
>
>         modified:   .gitmodules
>         modified:   linux (new commits)
>
> trace: run_command: 'submodule' 'summary' '--cached' '--for-status'
> '--summary-limit' '-1' 'HEAD'
> trace: exec: 'git' 'submodule' 'summary' '--cached' '--for-status'
> '--summary-limit' '-1' 'HEAD'
> trace: exec: 'git-submodule' 'summary' '--cached' '--for-status'
> '--summary-limit' '-1' 'HEAD'
> trace: run_command: 'git-submodule' 'summary' '--cached'
> '--for-status' '--summary-limit' '-1' 'HEAD'
> trace: built-in: git 'rev-parse' '--git-dir'
> trace: built-in: git 'rev-parse' '-q' '--git-dir'
> trace: built-in: git 'rev-parse' '--show-prefix'
> trace: built-in: git 'rev-parse' '--show-toplevel'
> trace: built-in: git 'rev-parse' '-q' '--verify' '--default' 'HEAD' 'HEAD'
> trace: built-in: git 'hash-object' '-w' '-t' 'tree' '--stdin'
> trace: built-in: git 'rev-parse' '--show-toplevel'
> trace: built-in: git 'rev-parse' '--sq' '--prefix' '' '--'
> trace: built-in: git 'diff-index' '--cached'
> '--ignore-submodules=dirty' '--raw'
> '4b825dc642cb6eb9a060e54bf8d69288fbee4904' '--'
> trace: built-in: git 'config' '-f' '.gitmodules' '--get-regexp'
> '^submodule\..*\.path$'
> trace: built-in: git 'config' 'submodule.rootfs.ignore'
> trace: built-in: git 'config' '-f' '.gitmodules' 'submodule.rootfs.ignore'
> trace: built-in: git 'config' '-f' '.gitmodules' '--get-regexp'
> '^submodule\..*\.path$'
> trace: built-in: git 'config' 'submodule.build.ignore'
> trace: built-in: git 'config' '-f' '.gitmodules' 'submodule.build.ignore'
> trace: built-in: git 'config' '-f' '.gitmodules' '--get-regexp'
> '^submodule\..*\.path$'
> trace: built-in: git 'config' 'submodule.linux.ignore'
> trace: built-in: git 'config' '-f' '.gitmodules' 'submodule.linux.ignore'
> trace: built-in: git 'diff-index' '--cached'
> '--ignore-submodules=dirty' '--raw'
> '4b825dc642cb6eb9a060e54bf8d69288fbee4904' '--' 'rootfs' 'build'
> 'linux'
> trace: built-in: git 'rev-parse' '-q' '--verify'
> 'e4bbdf3b45828a2e9ca37ef329b8e708e324dfb1^0'
> trace: built-in: git 'rev-list' '--first-parent'
> 'e4bbdf3b45828a2e9ca37ef329b8e708e324dfb1' '--'
> trace: built-in: git 'log' '--pretty=format:  > %s' '-1'
> 'e4bbdf3b45828a2e9ca37ef329b8e708e324dfb1'
> trace: built-in: git 'rev-parse' '-q' '--verify'
> '9f2d1659df78ea51eaa9ad5e7af9271996ac2a4c^0'
> trace: built-in: git 'rev-list' '--first-parent'
> '9f2d1659df78ea51eaa9ad5e7af9271996ac2a4c' '--'
> trace: built-in: git 'log' '--pretty=format:  > %s' '-1'
> '9f2d1659df78ea51eaa9ad5e7af9271996ac2a4c'
> trace: built-in: git 'rev-parse' '-q' '--verify'
> '7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9^0'
> trace: built-in: git 'rev-list' '--first-parent'
> '7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9' '--'
> trace: built-in: git 'log' '--pretty=format:  > %s' '-1'
> '7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9'
> Submodule changes to be committed:
>
> * rootfs 0000000...e4bbdf3 (249):
>   > Merge remote-tracking branch 'tomahawk/delivery_545_icmp'
>
> * build 0000000...9f2d165 (771):
>   > Merge remote-tracking branch 'plusplus/3rdparty'
>
> * linux 0000000...7d1311b (46122):
>   > Linux 3.17-rc1
>
> trace: run_command: 'submodule' 'summary' '--files' '--for-status'
> '--summary-limit' '-1'
> trace: exec: 'git' 'submodule' 'summary' '--files' '--for-status'
> '--summary-limit' '-1'
> trace: exec: 'git-submodule' 'summary' '--files' '--for-status'
> '--summary-limit' '-1'
> trace: run_command: 'git-submodule' 'summary' '--files' '--for-status'
> '--summary-limit' '-1'
> trace: built-in: git 'rev-parse' '--git-dir'
> trace: built-in: git 'rev-parse' '-q' '--git-dir'
> trace: built-in: git 'rev-parse' '--show-prefix'
> trace: built-in: git 'rev-parse' '--show-toplevel'
> trace: built-in: git 'rev-parse' '-q' '--verify' '--default' 'HEAD'
> trace: built-in: git 'hash-object' '-w' '-t' 'tree' '--stdin'
> trace: built-in: git 'rev-parse' '--show-toplevel'
> trace: built-in: git 'rev-parse' '--sq' '--prefix' '' '--'
> trace: built-in: git 'diff-files' '--ignore-submodules=dirty' '--raw' '--'
> trace: built-in: git 'config' '-f' '.gitmodules' '--get-regexp'
> '^submodule\..*\.path$'
> trace: built-in: git 'config' 'submodule.linux.ignore'
> trace: built-in: git 'config' '-f' '.gitmodules' 'submodule.linux.ignore'
> trace: built-in: git 'diff-files' '--ignore-submodules=dirty' '--raw'
> '--' 'linux'
> trace: built-in: git 'rev-parse' 'HEAD'
> trace: built-in: git 'rev-parse' '-q' '--verify'
> '7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9^0'
> trace: built-in: git 'rev-parse' '-q' '--verify'
> '14aa272fcd1cdbe7173073250c767bc7a37278ce^0'
> trace: built-in: git 'rev-list' '--first-parent'
> '7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9...14aa272fcd1cdbe7173073250c767bc7a37278ce'
> '--'
> trace: built-in: git 'log' '--pretty=format:  %m %s' '--first-parent'
> '7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9...14aa272fcd1cdbe7173073250c767bc7a37278ce'
> ^C