Git does not apply deleted files when merging an old branch into the master. How can I tell Git to apply deleted files?

Question

I have a master and a dev branch. I made commits in both. I also deleted some files in dev. I made other commit in master, so this master branch is more recent.

My i

Answer 1

Merges definitely delete files when there's not a conflict with changes in branches.

git does not preserve files during merging if they are deleted in the merging branch. - Nils_M

To prove it to myself, I had to try to reproduce your scenario. See this demonstration in hopes that you can see what it is you are doing differently.

create a new repository

mkdir test
cd test
git init

Initialized empty Git repository in /test/.git/

create and add some files to master branch

echo one > 1.txt
echo two > 2.txt
git add .
git commit -m "init repo"

[master (root-commit) feaa910] init repo
2 files changed, 2 insertions(+)
create mode 100644 1.txt
create mode 100644 2.txt

create new branch and add/delete some files

git checkout -b new

Switched to a new branch 'new'

echo three > 3.txt
rm 2.txt 
git add .
git status

On branch new
Changes to be committed:
(use "git reset HEAD ..." to unstage)

deleted: 2.txt
new file: 3.txt

git commit -m "changes in new"

[new db6b1a0] changes in new
2 files changed, 1 insertion(+), 1 deletion(-)
delete mode 100644 2.txt
create mode 100644 3.txt

commit some more changes in master

git checkout master

Switched to branch 'master'

echo update >> 1.txt 
git commit -am "update master"

[master 912a520] update master
1 file changed, 1 insertion(+)

tree

.
├── 1.txt
└── 2.txt

verify files still deleted in new

git checkout new

Switched to branch 'new'

tree

.
├── 1.txt
└── 3.txt

merge new into master

git checkout master

Switched to branch 'master'

git merge new master

Removing 2.txt
Merge made by the 'recursive' strategy.
2.txt | 1 -
3.txt | 1 +
2 files changed, 1 insertion(+), 1 deletion(-)
delete mode 100644 2.txt
create mode 100644 3.txt

tree

.
├── 1.txt
└── 3.txt

as you can see, the file 2.txt deleted in the new branch is now definitely deleted in master following the merge.