Re: files deleted with no record?

From: "Phil Hord" <redacted>

On Mon, Jun 23, 2014 at 9:15 PM, Jeremy Scott 
[off-list ref] wrote:

quoted

I just encountered a situation where a merge was made, with no
apparent changes in files (ie no log), but the result was that some
files were deleted.

person A adds some files
person B adds some files from the same point

You mean from the same point in history, right?  Not files with the
same filename or path?

quoted

person B commits and pushes.
person A commits -- now merge is required
a few more commits on top of person B's commit

I don't understand this step.  Who adds a few more commits on top of B 
and why?

quoted

person A merges - this removes the files that B added. There is no 
log
of the files being deleted

A similar issue, by reference, just came up on the [git-users] list. The 
reference was:
1. http://randyfay.com/content/avoiding-git-disasters-gory-story

In that case the problem was a mixture of tools and  misunderstandings.

It may not be the same as your case, but could give insights into what's 
happening between different developers.

Which Tools are You, person A and Person B using, with --version?

This sounds like an "evil merge" (see man gitglossary, and google),
but it's not clear to me how you arrived here.

When I tried to reproduce your issue with this script, it did not
remove any files unexpectedly:
------------------->8-----------------------
#!/bin/sh

set -e
mkdir foo && cd foo && git init
echo foo > foo && git add foo && git commit -mfoo

git checkout -b PersonA master
echo bar > bar && git add bar
git commit -m"PersonA: bar"

git checkout -b PersonB master
echo baz > baz && git add baz
git commit -m"PersonB: baz"

echo foo-conflict >> foo && git add foo
git commit -m"PersonB: foo"

git checkout PersonA
echo foo-different >> foo && git add foo
git commit -m"PersonA: foo (conflicts with PersonB)"

git log --oneline --all --stat

if ! git merge PersonB ; then
 git checkout PersonA foo
 git commit --no-edit
fi
git log --oneline --graph --stat
------------------->8-----------------------

A sneaky issue with merges is that they do not have a clear way to
show patch information -- the diff between the commit and its ancestor
-- because they have multiple ancestors.  You can show diffs for a
merge relative to each of its parents, but it is not usually done for
you automatically.  This is why making changes in a merge which are
not actually required for the merge is bad ("evil").

quoted

Clearly this is possible - was this a user error?

Probably, but we'd need to see how the user got there.
--

Philip