Use git.HOME_PATH for Git HOME directory (#20114)

* Add git.HOME_PATH

* add legacy file check

* Apply suggestions from code review

Co-authored-by: zeripath <art27@cantab.net>

* pass env GNUPGHOME to git command, move the existing .gitconfig to new home, make the fix for 1.17rc more clear.

* set git.HOME_PATH for docker images to default HOME

* Revert "set git.HOME_PATH for docker images to default HOME"

This reverts commit f120101ddc267cef74e4f4b92c783d5fc8e275a1.

* force Gitea to use a stable GNUPGHOME directory

* extra check to ensure only process dir or symlink for legacy files

* refactor variable name

* The legacy dir check (for 1.17-rc1) could be removed with 1.18 release, since users should have upgraded from 1.17-rc to 1.17-stable

* Update modules/git/git.go

Co-authored-by: Steven Kriegler <61625851+justusbunsi@users.noreply.github.com>

* remove initFixGitHome117rc

* Update git.go

* Update docs/content/doc/advanced/config-cheat-sheet.en-us.md

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Steven Kriegler <61625851+justusbunsi@users.noreply.github.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

2 files changed, 6 insertions, 3 deletions

diff --git a/docs/content/doc/advanced/config-cheat-sheet.en-us.md b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
index c16a500ef3..84e3c6ae33 100644
--- a/docs/content/doc/advanced/config-cheat-sheet.en-us.md
+++ b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
@@ -948,6 +948,8 @@ Default templates for project boards:
 ## Git (`git`)
 
 - `PATH`: **""**: The path of Git executable. If empty, Gitea searches through the PATH environment.
+- `HOME_PATH`: **%(APP_DATA_PATH)/home**: The HOME directory for Git.
+	  This directory will be used to contain the `.gitconfig` and possible `.gnupg` directories that Gitea's git calls will use. If you can confirm Gitea is the only application running in this environment, you can set it to the normal home directory for Gitea user.
 - `DISABLE_DIFF_HIGHLIGHT`: **false**: Disables highlight of added and removed changes.
 - `MAX_GIT_DIFF_LINES`: **1000**: Max number of lines allowed of a single file in diff view.
 - `MAX_GIT_DIFF_LINE_CHARACTERS`: **5000**: Max character count per line highlighted in diff view.
diff --git a/docs/content/doc/advanced/signing.en-us.md b/docs/content/doc/advanced/signing.en-us.md
index 8ae2f94e9e..9ef94deb75 100644
--- a/docs/content/doc/advanced/signing.en-us.md
+++ b/docs/content/doc/advanced/signing.en-us.md
@@ -97,10 +97,11 @@ repositories, `SIGNING_KEY=default` could be used to provide different
 signing keys on a per-repository basis. However, this is clearly not an
 ideal UI and therefore subject to change.
 
-**Since 1.17**, Gitea runs git in its own home directory `[repository].ROOT` and uses its own config `{[repository].ROOT}/.gitconfig`.
+**Since 1.17**, Gitea runs git in its own home directory `[git].HOME_PATH` (default to `%(APP_DATA_PATH)/home`)
+and uses its own config `{[git].HOME_PATH}/.gitconfig`.
 If you have your own customized git config for Gitea, you should set these configs in system git config (aka `/etc/gitconfig`)
-or the Gitea internal git config `{[repository].ROOT}/.gitconfig`. 
-Related home files for git command (like `.gnupg`) should also be put in Gitea's git home directory `[repository].ROOT`. 
+or the Gitea internal git config `{[git].HOME_PATH}/.gitconfig`. 
+Related home files for git command (like `.gnupg`) should also be put in Gitea's git home directory `[git].HOME_PATH`. 
 
 
 ### `INITIAL_COMMIT`