Git not commiting anything if file created and "git add"ed in pre-commit hook is the only file in the staging area

[Peter Hunkeler <phunsoft@gmx.net>]

Hi,
Git seems to behave inconsistently when creating and "git add"ing
content (files) from within a pre-commit hook. It claims there is
"nothing to commit", if the stating area was empty before the commit
command. Otherwise, the new content becomes part of the commit. See
details on how to reproduce and a log of the individual steps below.

Regards
Peter


=== Amended Git bug report
=============================================================================================
Thank you for filling out a Git bug report!
Please answer the following questions to help us understand your issue.

What did you do before the bug happened? (Steps to reproduce your issue)

I'm quite new to using git, so please bear with me should I mix up some
terminology.

I need some new file to be created at each commit. The new file must
become part of the commit.
I thought a git pre-commit hook would be the appropriate place. While
the file is created as desired,
git does *not* include this new file in the commit, when there is
nothing else in the staging area. It
reports the new file as being untracked, and says nothing added to
commit. A git status immediately
thereafter does, however, show the new file in the staging area. If I
run another commit just now, another
new file is created as expected, but this time, git adds them both to
the commit. This can be reliably
reproduced by repeating 'git commit -m "empty"', and every second time,
the commit is done.

Further testing shows that the newly created file *is* added to the
commit, *if* at least one other change
was registered to be commited (git add some time before the git commit).

Same behaviour, if two files are created and added withing the
pre-commit hook. Both files are added to
the commit only every second time, or if some other change does exist in
the staging area before the commit
command.

The git pre-commit hook looks like this (indented for readability, only):
     #!/bin/bash
     fn="folder1\folder1_file3_$(date +%Y%m%d_%H%M%S).txt"
     echo "some text" > $fn
     git add $fn

Note: This testing was done on Windows 10, but initially, I detected
this on a server running Linux.






What did you expect to happen? (Expected behavior)

I expect the file created and added from within the git pre-commit hook
to become part of the commit
no matter whether there are or aren't any other changes in the staging
are, i.e. added beforehand.




What happened instead? (Actual behavior)

File created and 'git added' from within the pre-commit hook shell
script is *not* added to the current
commit, if there are no other changes in the staging area.

The behaviour is inconsistent. If it is allowed to do a "git add" from
within a pre-commit hook (is it allowed?),
then file added must become part of the commit irrespective of whether
or not there are other changes in the
staging area that have been there *before* the commit command was
issued. Else git should reject the "git add"
(and other commands) from within the pre-commit hook.

What's different between what you expected and what actually happened?

see above,






Anything else you want to add:

I'm adding the log from a terminal session where I reproduce the
behaviour below, limited by a line
of '=' signs. Individual commands are separated by a line of '-' signs
with a comment what the next step
will be.

========================================================================================================


--- content of directory before git init
---------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ ls -lR
.:
total 6
-rw-r--r-- 1 Peter 197121 9 Oct 25 13:55 file1.txt
-rw-r--r-- 1 Peter 197121 9 Oct 25 13:55 file2.txt
drwxr-xr-x 1 Peter 197121 0 Oct 25 14:19 folder1/
drwxr-xr-x 1 Peter 197121 0 Oct 25 14:16 git-hook-saved/

./folder1:
total 2
-rw-r--r-- 1 Peter 197121 9 Oct 25 13:58 folder1_file1.txt
-rw-r--r-- 1 Peter 197121 9 Oct 25 13:58 folder1_file2.txt

./git-hook-saved:
total 1
-rwxr-xr-x 1 Peter 197121 111 Oct 25 14:21 pre-commit*


--- git init
-----------------------------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing
$ git init
Initialized empty Git repository in D:/Temp/git-testing/.git/


--- git initial status
-------------------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git status
On branch master

No commits yet

Untracked files:
   (use "git add <file>..." to include in what will be committed)
         file1.txt
         file2.txt
         folder1/
         git-hook-saved/

nothing added to commit but untracked files present (use "git add" to track)


--- adding all initial data to the staging area
---------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git add "*"


--- commiting initial data
------------------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git commit -m "initial commit"
[master (root-commit) 4daefe7] initial commit
  5 files changed, 12 insertions(+)
  create mode 100644 file1.txt
  create mode 100644 file2.txt
  create mode 100644 folder1/folder1_file1.txt
  create mode 100644 folder1/folder1_file2.txt
  create mode 100644 git-hook-saved/pre-commit


--- Show status after initial commit
-----------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git status
On branch master
nothing to commit, working tree clean


--- Install git pre-commit hook, then do an empty commit
-------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git commit -m "empty 1"
warning: LF will be replaced by CRLF in
folder1/folder1_file3_20211025_142454.txt.
The file will have its original line endings in your working directory
On branch master
Untracked files:
   (use "git add <file>..." to include in what will be committed)
         folder1/folder1_file3_20211025_142454.txt

nothing added to commit but untracked files present (use "git add" to track)


--- Show whats in the file system at this point in time
-------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ ls -lR
.:
total 6
-rw-r--r-- 1 Peter 197121 9 Oct 25 13:55 file1.txt
-rw-r--r-- 1 Peter 197121 9 Oct 25 13:55 file2.txt
drwxr-xr-x 1 Peter 197121 0 Oct 25 14:24 folder1/
drwxr-xr-x 1 Peter 197121 0 Oct 25 14:16 git-hook-saved/

./folder1:
total 3
-rw-r--r-- 1 Peter 197121  9 Oct 25 13:58 folder1_file1.txt
-rw-r--r-- 1 Peter 197121  9 Oct 25 13:58 folder1_file2.txt
-rw-r--r-- 1 Peter 197121 10 Oct 25 14:24 folder1_file3_20211025_142454.txt

./git-hook-saved:
total 1
-rwxr-xr-x 1 Peter 197121 111 Oct 25 14:21 pre-commit


--- What is the status of git? The "add" from the hook did
work!------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git status
On branch master
Changes to be committed:
   (use "git restore --staged <file>..." to unstage)
         new file:   folder1/folder1_file3_20211025_142454.txt


--- Immediately do another (not really empty) git commit
-------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git commit -m "empty 2"
warning: LF will be replaced by CRLF in
folder1/folder1_file3_20211025_142554.txt.
The file will have its original line endings in your working directory
[master e9809aa] empty 2
  2 files changed, 2 insertions(+)
  create mode 100644 folder1/folder1_file3_20211025_142454.txt
  create mode 100644 folder1/folder1_file3_20211025_142554.txt


--- Show whats in the file system at this point in time
-------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ ls -lR
.:
total 6
-rw-r--r-- 1 Peter 197121 9 Oct 25 13:55 file1.txt
-rw-r--r-- 1 Peter 197121 9 Oct 25 13:55 file2.txt
drwxr-xr-x 1 Peter 197121 0 Oct 25 14:25 folder1/
drwxr-xr-x 1 Peter 197121 0 Oct 25 14:16 git-hook-saved/

./folder1:
total 4
-rw-r--r-- 1 Peter 197121  9 Oct 25 13:58 folder1_file1.txt
-rw-r--r-- 1 Peter 197121  9 Oct 25 13:58 folder1_file2.txt
-rw-r--r-- 1 Peter 197121 10 Oct 25 14:24 folder1_file3_20211025_142454.txt
-rw-r--r-- 1 Peter 197121 10 Oct 25 14:25 folder1_file3_20211025_142554.txt

./git-hook-saved:
total 1
-rwxr-xr-x 1 Peter 197121 111 Oct 25 14:21 pre-commit


--- Once more, this time really an "empty" commit again.
------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git commit -m "empty 3"
warning: LF will be replaced by CRLF in
folder1/folder1_file3_20211025_142645.txt.
The file will have its original line endings in your working directory
On branch master
Untracked files:
   (use "git add <file>..." to include in what will be committed)
         folder1/folder1_file3_20211025_142645.txt

nothing added to commit but untracked files present (use "git add" to track)


--- Show the status, same behaviour again.
---------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git status
On branch master
Changes to be committed:
   (use "git restore --staged <file>..." to unstage)
         new file:   folder1/folder1_file3_20211025_142645.txt


--- Yet another commit immediately thereafter
---------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git commit -m "empty 4"
warning: LF will be replaced by CRLF in
folder1/folder1_file3_20211025_142659.txt.
The file will have its original line endings in your working directory
[master 032a58e] empty 4
  2 files changed, 2 insertions(+)
  create mode 100644 folder1/folder1_file3_20211025_142645.txt
  create mode 100644 folder1/folder1_file3_20211025_142659.txt


--- Status?
---------------------------------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git status
On branch master
nothing to commit, working tree clean


--- Content of filesystem
---------------------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ ls -lR
.:
total 7
-rw-r--r-- 1 Peter 197121  9 Oct 25 13:55 file1.txt
-rw-r--r-- 1 Peter 197121  9 Oct 25 13:55 file2.txt
-rw-r--r-- 1 Peter 197121 10 Oct 25 14:27 file3.txt
drwxr-xr-x 1 Peter 197121  0 Oct 25 14:28 folder1/
drwxr-xr-x 1 Peter 197121  0 Oct 25 14:16 git-hook-saved/

./folder1:
total 7
-rw-r--r-- 1 Peter 197121  9 Oct 25 13:58 folder1_file1.txt
-rw-r--r-- 1 Peter 197121  9 Oct 25 13:58 folder1_file2.txt
-rw-r--r-- 1 Peter 197121 10 Oct 25 14:24 folder1_file3_20211025_142454.txt
-rw-r--r-- 1 Peter 197121 10 Oct 25 14:25 folder1_file3_20211025_142554.txt
-rw-r--r-- 1 Peter 197121 10 Oct 25 14:26 folder1_file3_20211025_142645.txt
-rw-r--r-- 1 Peter 197121 10 Oct 25 14:26 folder1_file3_20211025_142659.txt
-rw-r--r-- 1 Peter 197121 10 Oct 25 14:28 folder1_file3_20211025_142815.txt

./git-hook-saved:
total 1
-rwxr-xr-x 1 Peter 197121 111 Oct 25 14:21 pre-commit


--- Creating a new file outside of hook
--------------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ echo "some text" > file3.txt


--- Git status?
------------------------------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git status
On branch master
Untracked files:
   (use "git add <file>..." to include in what will be committed)
         file3.txt

nothing added to commit but untracked files present (use "git add" to track)


--- Adding the new file to the staging area
------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git add *
warning: LF will be replaced by CRLF in file3.txt.
The file will have its original line endings in your working directory


--- Status again
----------------------------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git status
On branch master
Changes to be committed:
   (use "git restore --staged <file>..." to unstage)
         new file:   file3.txt


--- Committing the new file (and the one created by the pre-commit hook)
--------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git commit -m "one new file present"
warning: LF will be replaced by CRLF in
folder1/folder1_file3_20211025_142815.txt.
The file will have its original line endings in your working directory
[master 4ea47ec] one new file present
  2 files changed, 2 insertions(+)
  create mode 100644 file3.txt
  create mode 100644 folder1/folder1_file3_20211025_142815.txt


--- Status?
--------------------------------------------------------------------
Peter@MySystem MINGW64 /d/Temp/git-testing (master)
$ git status
On branch master
nothing to commit, working tree clean



========================================================================================================








Please review the rest of the bug report below.
You can delete any lines you don't wish to share.


[System Info]
git version:
git version 2.32.0.windows.2
cpu: x86_64
built from commit: 3d45ac813c4adf97fe3733c1f763ab6617d5add5
sizeof-long: 4
sizeof-size_t: 8
shell-path: /bin/sh
feature: fsmonitor--daemon
uname: Windows 10.0 19042
compiler info: gnuc: 10.3
libc info: no libc information available
$SHELL (typically, interactive shell): C:\Programme
Non-UAC\Git\usr\bin\bash.exe


[Enabled Hooks]
pre-commit