Create a branch directly from commit on the create branch API (#22956)

#### Added
- API: Create a branch directly from commit on the create branch API
- Added `old_ref_name` parameter to allow creating a new branch from a
specific commit, tag, or branch.
- Deprecated `old_branch_name` parameter in favor of the new
`old_ref_name` parameter.

---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

modules/structs/repo.go

@@ -249,10 +249,16 @@ type CreateBranchRepoOption struct {
 	// unique: true
 	BranchName string `json:"new_branch_name" binding:"Required;GitRefName;MaxSize(100)"`
 
+	// Deprecated: true
 	// Name of the old branch to create from
 	//
 	// unique: true
 	OldBranchName string `json:"old_branch_name" binding:"GitRefName;MaxSize(100)"`
+
+	// Name of the old branch/tag/commit to create from
+	//
+	// unique: true
+	OldRefName string `json:"old_ref_name" binding:"GitRefName;MaxSize(100)"`
 }
 
 // TransferRepoOption options when transfer a repository's ownership

routers/api/v1/repo/branch.go

@@ -173,11 +173,35 @@ func CreateBranch(ctx *context.APIContext) {
 		return
 	}
 
-	if len(opt.OldBranchName) == 0 {
-		opt.OldBranchName = ctx.Repo.Repository.DefaultBranch
+	var oldCommit *git.Commit
+	var err error
+
+	if len(opt.OldRefName) > 0 {
+		oldCommit, err = ctx.Repo.GitRepo.GetCommit(opt.OldRefName)
+		if err != nil {
+			ctx.Error(http.StatusInternalServerError, "GetCommit", err)
+			return
+		}
+	} else if len(opt.OldBranchName) > 0 { //nolint
+		if ctx.Repo.GitRepo.IsBranchExist(opt.OldBranchName) { //nolint
+			oldCommit, err = ctx.Repo.GitRepo.GetBranchCommit(opt.OldBranchName) //nolint
+			if err != nil {
+				ctx.Error(http.StatusInternalServerError, "GetBranchCommit", err)
+				return
+			}
+		} else {
+			ctx.Error(http.StatusNotFound, "", "The old branch does not exist")
+			return
+		}
+	} else {
+		oldCommit, err = ctx.Repo.GitRepo.GetBranchCommit(ctx.Repo.Repository.DefaultBranch)
+		if err != nil {
+			ctx.Error(http.StatusInternalServerError, "GetBranchCommit", err)
+			return
+		}
 	}
 
-	err := repo_service.CreateNewBranch(ctx, ctx.Doer, ctx.Repo.Repository, opt.OldBranchName, opt.BranchName)
+	err = repo_service.CreateNewBranchFromCommit(ctx, ctx.Doer, ctx.Repo.Repository, oldCommit.ID.String(), opt.BranchName)
 	if err != nil {
 		if models.IsErrBranchDoesNotExist(err) {
 			ctx.Error(http.StatusNotFound, "", "The old branch does not exist")
@@ -189,7 +213,7 @@ func CreateBranch(ctx *context.APIContext) {
 		} else if models.IsErrBranchNameConflict(err) {
 			ctx.Error(http.StatusConflict, "", "The branch with the same name already exists.")
 		} else {
-			ctx.Error(http.StatusInternalServerError, "CreateRepoBranch", err)
+			ctx.Error(http.StatusInternalServerError, "CreateNewBranchFromCommit", err)
 		}
 		return
 	}

templates/swagger/v1_json.tmpl

@@ -16145,10 +16145,16 @@
           "x-go-name": "BranchName"
         },
         "old_branch_name": {
-          "description": "Name of the old branch to create from",
+          "description": "Deprecated: true\nName of the old branch to create from",
           "type": "string",
           "uniqueItems": true,
           "x-go-name": "OldBranchName"
+        },
+        "old_ref_name": {
+          "description": "Name of the old branch/tag/commit to create from",
+          "type": "string",
+          "uniqueItems": true,
+          "x-go-name": "OldRefName"
         }
       },
       "x-go-package": "code.gitea.io/gitea/modules/structs"