Simplify how git repositories are opened (#28937)

## Purpose
This is a refactor toward building an abstraction over managing git
repositories.
Afterwards, it does not matter anymore if they are stored on the local
disk or somewhere remote.

## What this PR changes
We used `git.OpenRepository` everywhere previously.
Now, we should split them into two distinct functions:

Firstly, there are temporary repositories which do not change:

```go
git.OpenRepository(ctx, diskPath)
```

Gitea managed repositories having a record in the database in the
`repository` table are moved into the new package `gitrepo`:

```go
gitrepo.OpenRepository(ctx, repo_model.Repo)
```

Why is `repo_model.Repository` the second parameter instead of file
path?
Because then we can easily adapt our repository storage strategy.
The repositories can be stored locally, however, they could just as well
be stored on a remote server.

## Further changes in other PRs
- A Git Command wrapper on package `gitrepo` could be created. i.e.
`NewCommand(ctx, repo_model.Repository, commands...)`. `git.RunOpts{Dir:
repo.RepoPath()}`, the directory should be empty before invoking this
method and it can be filled in the function only. #28940
- Remove the `RepoPath()`/`WikiPath()` functions to reduce the
possibility of mistakes.

---------

Co-authored-by: delvh <dev.lh@web.de>

3 files changed, 11 insertions, 12 deletions

diff --git a/modules/context/api.go b/modules/context/api.go
index f41228ad76..e226264a87 100644
--- a/modules/context/api.go
+++ b/modules/context/api.go
@@ -11,11 +11,11 @@ import (
 	"net/url"
 	"strings"
 
-	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unit"
 	user_model "code.gitea.io/gitea/models/user"
 	mc "code.gitea.io/gitea/modules/cache"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/gitrepo"
 	"code.gitea.io/gitea/modules/httpcache"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -224,7 +224,7 @@ func APIContexter() func(http.Handler) http.Handler {
 			defer baseCleanUp()
 
 			ctx.Base.AppendContextValue(apiContextKey, ctx)
-			ctx.Base.AppendContextValueFunc(git.RepositoryContextKey, func() any { return ctx.Repo.GitRepo })
+			ctx.Base.AppendContextValueFunc(gitrepo.RepositoryContextKey, func() any { return ctx.Repo.GitRepo })
 
 			// If request sends files, parse them here otherwise the Query() can't be parsed and the CsrfToken will be invalid.
 			if ctx.Req.Method == "POST" && strings.Contains(ctx.Req.Header.Get("Content-Type"), "multipart/form-data") {
@@ -278,10 +278,9 @@ func ReferencesGitRepo(allowEmpty ...bool) func(ctx *APIContext) (cancel context
 
 		// For API calls.
 		if ctx.Repo.GitRepo == nil {
-			repoPath := repo_model.RepoPath(ctx.Repo.Owner.Name, ctx.Repo.Repository.Name)
-			gitRepo, err := git.OpenRepository(ctx, repoPath)
+			gitRepo, err := gitrepo.OpenRepository(ctx, ctx.Repo.Repository)
 			if err != nil {
-				ctx.Error(http.StatusInternalServerError, "RepoRef Invalid repo "+repoPath, err)
+				ctx.Error(http.StatusInternalServerError, fmt.Sprintf("Open Repository %v failed", ctx.Repo.Repository.FullName()), err)
 				return cancel
 			}
 			ctx.Repo.GitRepo = gitRepo
diff --git a/modules/context/context.go b/modules/context/context.go
index 8a94e958b5..d19c5d1198 100644
--- a/modules/context/context.go
+++ b/modules/context/context.go
@@ -17,7 +17,7 @@ import (
 	"code.gitea.io/gitea/models/unit"
 	user_model "code.gitea.io/gitea/models/user"
 	mc "code.gitea.io/gitea/modules/cache"
-	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/gitrepo"
 	"code.gitea.io/gitea/modules/httpcache"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/templates"
@@ -163,7 +163,7 @@ func Contexter() func(next http.Handler) http.Handler {
 			ctx.Data["PageData"] = ctx.PageData
 
 			ctx.Base.AppendContextValue(WebContextKey, ctx)
-			ctx.Base.AppendContextValueFunc(git.RepositoryContextKey, func() any { return ctx.Repo.GitRepo })
+			ctx.Base.AppendContextValueFunc(gitrepo.RepositoryContextKey, func() any { return ctx.Repo.GitRepo })
 
 			ctx.Csrf = PrepareCSRFProtector(csrfOpts, ctx)
 
diff --git a/modules/context/repo.go b/modules/context/repo.go
index 8d82be1990..75ebfec705 100644
--- a/modules/context/repo.go
+++ b/modules/context/repo.go
@@ -23,6 +23,7 @@ import (
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/cache"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/gitrepo"
 	code_indexer "code.gitea.io/gitea/modules/indexer/code"
 	"code.gitea.io/gitea/modules/log"
 	repo_module "code.gitea.io/gitea/modules/repository"
@@ -633,7 +634,7 @@ func RepoAssignment(ctx *Context) context.CancelFunc {
 		return nil
 	}
 
-	gitRepo, err := git.OpenRepository(ctx, repo_model.RepoPath(userName, repoName))
+	gitRepo, err := gitrepo.OpenRepository(ctx, repo)
 	if err != nil {
 		if strings.Contains(err.Error(), "repository does not exist") || strings.Contains(err.Error(), "no such file or directory") {
 			log.Error("Repository %-v has a broken repository on the file system: %s Error: %v", ctx.Repo.Repository, ctx.Repo.Repository.RepoPath(), err)
@@ -645,7 +646,7 @@ func RepoAssignment(ctx *Context) context.CancelFunc {
 			}
 			return nil
 		}
-		ctx.ServerError("RepoAssignment Invalid repo "+repo_model.RepoPath(userName, repoName), err)
+		ctx.ServerError("RepoAssignment Invalid repo "+repo.FullName(), err)
 		return nil
 	}
 	if ctx.Repo.GitRepo != nil {
@@ -920,10 +921,9 @@ func RepoRefByType(refType RepoRefType, ignoreNotExistErr ...bool) func(*Context
 		)
 
 		if ctx.Repo.GitRepo == nil {
-			repoPath := repo_model.RepoPath(ctx.Repo.Owner.Name, ctx.Repo.Repository.Name)
-			ctx.Repo.GitRepo, err = git.OpenRepository(ctx, repoPath)
+			ctx.Repo.GitRepo, err = gitrepo.OpenRepository(ctx, ctx.Repo.Repository)
 			if err != nil {
-				ctx.ServerError("RepoRef Invalid repo "+repoPath, err)
+				ctx.ServerError(fmt.Sprintf("Open Repository %v failed", ctx.Repo.Repository.FullName()), err)
 				return nil
 			}
 			// We opened it, we should close it