diff --git a/contrib/autocompletion/bash_autocomplete b/contrib/autocompletion/bash_autocomplete
index 58844938a6..5cb62f26a7 100755
--- a/contrib/autocompletion/bash_autocomplete
+++ b/contrib/autocompletion/bash_autocomplete
@@ -1,3 +1,4 @@
+#! /bin/bash
 # Heavily inspired by https://github.com/urfave/cli
 
 _cli_bash_autocomplete() {
@@ -6,9 +7,9 @@ _cli_bash_autocomplete() {
     COMPREPLY=()
     cur="${COMP_WORDS[COMP_CWORD]}"
     if [[ "$cur" == "-"* ]]; then
-      opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} ${cur} --generate-shell-completion )
+      opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} ${cur} --generate-bash-completion )
     else
-      opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} --generate-shell-completion )
+      opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} --generate-bash-completion )
     fi
     COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
     return 0
diff --git a/contrib/autocompletion/zsh_autocomplete b/contrib/autocompletion/zsh_autocomplete
index 0fd1a0b175..b3b40df503 100644
--- a/contrib/autocompletion/zsh_autocomplete
+++ b/contrib/autocompletion/zsh_autocomplete
@@ -9,9 +9,9 @@ _cli_zsh_autocomplete() {
   local cur
   cur=${words[-1]}
   if [[ "$cur" == "-"* ]]; then
-    opts=("${(@f)$(_CLI_ZSH_AUTOCOMPLETE_HACK=1 ${words[@]:0:#words[@]-1} ${cur} --generate-shell-completion)}")
+    opts=("${(@f)$(_CLI_ZSH_AUTOCOMPLETE_HACK=1 ${words[@]:0:#words[@]-1} ${cur} --generate-bash-completion)}")
   else
-    opts=("${(@f)$(_CLI_ZSH_AUTOCOMPLETE_HACK=1 ${words[@]:0:#words[@]-1} --generate-shell-completion)}")
+    opts=("${(@f)$(_CLI_ZSH_AUTOCOMPLETE_HACK=1 ${words[@]:0:#words[@]-1} --generate-bash-completion)}")
   fi
 
   if [[ "${opts[1]}" != "" ]]; then
diff --git a/models/error.go b/models/error.go
index ebaa8a135d..e8962f386b 100644
--- a/models/error.go
+++ b/models/error.go
@@ -414,7 +414,7 @@ func IsErrSHAOrCommitIDNotProvided(err error) bool {
 }
 
 func (err ErrSHAOrCommitIDNotProvided) Error() string {
-	return "a SHA or commit ID must be provided when updating a file"
+	return "a SHA or commit ID must be proved when updating a file"
 }
 
 // ErrInvalidMergeStyle represents an error if merging with disabled merge strategy
diff --git a/routers/api/v1/repo/file.go b/routers/api/v1/repo/file.go
index 549fe9fae0..3408f88dd1 100644
--- a/routers/api/v1/repo/file.go
+++ b/routers/api/v1/repo/file.go
@@ -480,8 +480,6 @@ func ChangeFiles(ctx *context.APIContext) {
 	//     "$ref": "#/responses/error"
 	//   "404":
 	//     "$ref": "#/responses/notFound"
-	//   "409":
-	//     "$ref": "#/responses/conflict"
 	//   "413":
 	//     "$ref": "#/responses/quotaExceeded"
 	//   "422":
@@ -586,8 +584,6 @@ func CreateFile(ctx *context.APIContext) {
 	//     "$ref": "#/responses/error"
 	//   "404":
 	//     "$ref": "#/responses/notFound"
-	//   "409":
-	//     "$ref": "#/responses/conflict"
 	//   "413":
 	//     "$ref": "#/responses/quotaExceeded"
 	//   "422":
@@ -688,8 +684,6 @@ func UpdateFile(ctx *context.APIContext) {
 	//     "$ref": "#/responses/error"
 	//   "404":
 	//     "$ref": "#/responses/notFound"
-	//   "409":
-	//     "$ref": "#/responses/conflict"
 	//   "413":
 	//     "$ref": "#/responses/quotaExceeded"
 	//   "422":
@@ -763,19 +757,11 @@ func handleCreateOrUpdateFileError(ctx *context.APIContext, err error) {
 		ctx.Error(http.StatusForbidden, "Access", err)
 		return
 	}
-	if git_model.IsErrBranchAlreadyExists(err) ||
-		models.IsErrFilenameInvalid(err) ||
-		models.IsErrSHAOrCommitIDNotProvided(err) ||
-		models.IsErrFilePathInvalid(err) ||
-		models.IsErrRepoFileAlreadyExists(err) {
+	if git_model.IsErrBranchAlreadyExists(err) || models.IsErrFilenameInvalid(err) || models.IsErrSHADoesNotMatch(err) ||
+		models.IsErrFilePathInvalid(err) || models.IsErrRepoFileAlreadyExists(err) {
 		ctx.Error(http.StatusUnprocessableEntity, "Invalid", err)
 		return
 	}
-	if models.IsErrCommitIDDoesNotMatch(err) ||
-		models.IsErrSHADoesNotMatch(err) {
-		ctx.Error(http.StatusConflict, "Conflict", err)
-		return
-	}
 	if git_model.IsErrBranchNotExist(err) || git.IsErrBranchNotExist(err) {
 		ctx.Error(http.StatusNotFound, "BranchDoesNotExist", err)
 		return
diff --git a/services/repository/files/update.go b/services/repository/files/update.go
index 8fb9644fa4..5e8834c6de 100644
--- a/services/repository/files/update.go
+++ b/services/repository/files/update.go
@@ -193,34 +193,28 @@ func ChangeRepoFiles(ctx context.Context, repo *repo_model.Repository, doer *use
 	}
 
 	if hasOldBranch {
-		// Get the current commit of the original branch
-		actualBaseCommit, err := t.GetBranchCommit(opts.OldBranch)
+		// Get the commit of the original branch
+		commit, err := t.GetBranchCommit(opts.OldBranch)
 		if err != nil {
 			return nil, err // Couldn't get a commit for the branch
 		}
 
-		var lastKnownCommit git.ObjectID // when nil, the sha provided in the opts.Files must match the current blob-sha
-		if opts.OldBranch != opts.NewBranch {
-			// when creating a new branch, ignore if a file has been changed in the meantime
-			// (such changes will visible when doing the merge)
-			lastKnownCommit = actualBaseCommit.ID
-		} else if opts.LastCommitID != "" {
-			lastKnownCommit, err = t.gitRepo.ConvertToGitID(opts.LastCommitID)
+		// Assigned LastCommitID in opts if it hasn't been set
+		if opts.LastCommitID == "" {
+			opts.LastCommitID = commit.ID.String()
+		} else {
+			lastCommitID, err := t.gitRepo.ConvertToGitID(opts.LastCommitID)
 			if err != nil {
 				return nil, fmt.Errorf("ConvertToSHA1: Invalid last commit ID: %w", err)
 			}
+			opts.LastCommitID = lastCommitID.String()
 		}
 
 		for _, file := range opts.Files {
-			if err := handleCheckErrors(file, actualBaseCommit, lastKnownCommit); err != nil {
+			if err := handleCheckErrors(file, commit, opts); err != nil {
 				return nil, err
 			}
 		}
-
-		if opts.LastCommitID == "" {
-			// needed for t.CommitTree
-			opts.LastCommitID = actualBaseCommit.ID.String()
-		}
 	}
 
 	contentStore := lfs.NewContentStore()
@@ -283,9 +277,9 @@ func ChangeRepoFiles(ctx context.Context, repo *repo_model.Repository, doer *use
 }
 
 // handles the check for various issues for ChangeRepoFiles
-func handleCheckErrors(file *ChangeRepoFile, actualBaseCommit *git.Commit, lastKnownCommit git.ObjectID) error {
+func handleCheckErrors(file *ChangeRepoFile, commit *git.Commit, opts *ChangeRepoFilesOptions) error {
 	if file.Operation == "update" || file.Operation == "delete" {
-		fromEntry, err := actualBaseCommit.GetTreeEntryByPath(file.Options.fromTreePath)
+		fromEntry, err := commit.GetTreeEntryByPath(file.Options.fromTreePath)
 		if err != nil {
 			return err
 		}
@@ -298,22 +292,22 @@ func handleCheckErrors(file *ChangeRepoFile, actualBaseCommit *git.Commit, lastK
 					CurrentSHA: fromEntry.ID.String(),
 				}
 			}
-		} else if lastKnownCommit != nil {
-			if actualBaseCommit.ID.String() != lastKnownCommit.String() {
-				// If a lastKnownCommit was given and it doesn't match the actualBaseCommit,
-				// check if the file has been changed in between
-				if changed, err := actualBaseCommit.FileChangedSinceCommit(file.Options.treePath, lastKnownCommit.String()); err != nil {
+		} else if opts.LastCommitID != "" {
+			// If a lastCommitID was given and it doesn't match the commitID of the head of the branch throw
+			// an error, but only if we aren't creating a new branch.
+			if commit.ID.String() != opts.LastCommitID && opts.OldBranch == opts.NewBranch {
+				if changed, err := commit.FileChangedSinceCommit(file.Options.treePath, opts.LastCommitID); err != nil {
 					return err
 				} else if changed {
 					return models.ErrCommitIDDoesNotMatch{
-						GivenCommitID:   lastKnownCommit.String(),
-						CurrentCommitID: actualBaseCommit.ID.String(),
+						GivenCommitID:   opts.LastCommitID,
+						CurrentCommitID: opts.LastCommitID,
 					}
 				}
-				// The file wasn't modified, so we are good to update it
+				// The file wasn't modified, so we are good to delete it
 			}
 		} else {
-			// When updating a file, a lastKnownCommit or SHA needs to be given to make sure other commits
+			// When updating a file, a lastCommitID or SHA needs to be given to make sure other commits
 			// haven't been made. We throw an error if one wasn't provided.
 			return models.ErrSHAOrCommitIDNotProvided{}
 		}
@@ -328,7 +322,7 @@ func handleCheckErrors(file *ChangeRepoFile, actualBaseCommit *git.Commit, lastK
 		subTreePath := ""
 		for index, part := range treePathParts {
 			subTreePath = path.Join(subTreePath, part)
-			entry, err := actualBaseCommit.GetTreeEntryByPath(subTreePath)
+			entry, err := commit.GetTreeEntryByPath(subTreePath)
 			if err != nil {
 				if git.IsErrNotExist(err) {
 					// Means there is no item with that name, so we're good
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 1b5f55f97b..557ea5ea2b 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -6897,9 +6897,6 @@
           "404": {
             "$ref": "#/responses/notFound"
           },
-          "409": {
-            "$ref": "#/responses/conflict"
-          },
           "413": {
             "$ref": "#/responses/quotaExceeded"
           },
@@ -7013,9 +7010,6 @@
           "404": {
             "$ref": "#/responses/notFound"
           },
-          "409": {
-            "$ref": "#/responses/conflict"
-          },
           "413": {
             "$ref": "#/responses/quotaExceeded"
           },
@@ -7080,9 +7074,6 @@
           "404": {
             "$ref": "#/responses/notFound"
           },
-          "409": {
-            "$ref": "#/responses/conflict"
-          },
           "413": {
             "$ref": "#/responses/quotaExceeded"
           },
diff --git a/tests/e2e/declare_repos_test.go b/tests/e2e/declare_repos_test.go
index 239a686f00..8b1a8536d7 100644
--- a/tests/e2e/declare_repos_test.go
+++ b/tests/e2e/declare_repos_test.go
@@ -78,7 +78,6 @@ func newRepo(t *testing.T, userID int64, repoName string, fileChanges []FileChan
 		nil,
 	)
 
-	var lastCommitID string
 	for _, file := range fileChanges {
 		for i, version := range file.Versions {
 			operation := "update"
@@ -113,12 +112,9 @@ func newRepo(t *testing.T, userID int64, repoName string, fileChanges []FileChan
 					Author:    time.Now(),
 					Committer: time.Now(),
 				},
-				LastCommitID: lastCommitID,
 			})
 			require.NoError(t, err)
 			assert.NotEmpty(t, resp)
-
-			lastCommitID = resp.Commit.SHA
 		}
 	}
 
diff --git a/tests/integration/api_issue_config_test.go b/tests/integration/api_issue_config_test.go
index 3653a859b1..809be572da 100644
--- a/tests/integration/api_issue_config_test.go
+++ b/tests/integration/api_issue_config_test.go
@@ -155,7 +155,7 @@ func TestAPIRepoIssueConfigPaths(t *testing.T) {
 				assert.False(t, issueConfig.BlankIssuesEnabled)
 				assert.Empty(t, issueConfig.ContactLinks)
 
-				err = deleteFileInBranch(owner, repo, fullPath, repo.DefaultBranch)
+				_, err = deleteFileInBranch(owner, repo, fullPath, repo.DefaultBranch)
 				require.NoError(t, err)
 			})
 		}
diff --git a/tests/integration/api_issue_templates_test.go b/tests/integration/api_issue_templates_test.go
index 47ba34198a..49b1a6f277 100644
--- a/tests/integration/api_issue_templates_test.go
+++ b/tests/integration/api_issue_templates_test.go
@@ -47,7 +47,9 @@ func TestAPIIssueTemplateList(t *testing.T) {
 			for _, template := range templateCandidates {
 				t.Run(template, func(t *testing.T) {
 					defer tests.PrintCurrentTest(t)()
-					defer deleteFileInBranch(user, repo, template, repo.DefaultBranch)
+					defer func() {
+						deleteFileInBranch(user, repo, template, repo.DefaultBranch)
+					}()
 
 					err := createOrReplaceFileInBranch(user, repo, template, repo.DefaultBranch,
 						`---
diff --git a/tests/integration/api_repo_file_helpers.go b/tests/integration/api_repo_file_helpers.go
index 61407bf1bf..09cf93d8a5 100644
--- a/tests/integration/api_repo_file_helpers.go
+++ b/tests/integration/api_repo_file_helpers.go
@@ -10,7 +10,6 @@ import (
 	repo_model "forgejo.org/models/repo"
 	user_model "forgejo.org/models/user"
 	"forgejo.org/modules/git"
-	"forgejo.org/modules/gitrepo"
 	api "forgejo.org/modules/structs"
 	files_service "forgejo.org/services/repository/files"
 )
@@ -31,12 +30,7 @@ func createFileInBranch(user *user_model.User, repo *repo_model.Repository, tree
 	return files_service.ChangeRepoFiles(git.DefaultContext, repo, user, opts)
 }
 
-func deleteFileInBranch(user *user_model.User, repo *repo_model.Repository, treePath, branchName string) error {
-	commitID, err := gitrepo.GetBranchCommitID(git.DefaultContext, repo, branchName)
-	if err != nil {
-		return err
-	}
-
+func deleteFileInBranch(user *user_model.User, repo *repo_model.Repository, treePath, branchName string) (*api.FilesResponse, error) {
 	opts := &files_service.ChangeRepoFilesOptions{
 		Files: []*files_service.ChangeRepoFile{
 			{
@@ -44,17 +38,16 @@ func deleteFileInBranch(user *user_model.User, repo *repo_model.Repository, tree
 				TreePath:  treePath,
 			},
 		},
-		OldBranch:    branchName,
-		Author:       nil,
-		Committer:    nil,
-		LastCommitID: commitID,
+		OldBranch: branchName,
+		Author:    nil,
+		Committer: nil,
 	}
-	_, err = files_service.ChangeRepoFiles(git.DefaultContext, repo, user, opts)
-	return err
+	return files_service.ChangeRepoFiles(git.DefaultContext, repo, user, opts)
 }
 
 func createOrReplaceFileInBranch(user *user_model.User, repo *repo_model.Repository, treePath, branchName, content string) error {
-	err := deleteFileInBranch(user, repo, treePath, branchName)
+	_, err := deleteFileInBranch(user, repo, treePath, branchName)
+
 	if err != nil && !models.IsErrRepoFileDoesNotExist(err) {
 		return err
 	}
diff --git a/tests/integration/api_repo_file_update_test.go b/tests/integration/api_repo_file_update_test.go
index 878d865aff..61deb10c92 100644
--- a/tests/integration/api_repo_file_update_test.go
+++ b/tests/integration/api_repo_file_update_test.go
@@ -214,7 +214,7 @@ func TestAPIUpdateFile(t *testing.T) {
 		updateFileOptions.SHA = "badsha"
 		req = NewRequestWithJSON(t, "PUT", fmt.Sprintf("/api/v1/repos/%s/%s/contents/%s", user2.Name, repo1.Name, treePath), &updateFileOptions).
 			AddTokenAuth(token2)
-		resp = MakeRequest(t, req, http.StatusConflict)
+		resp = MakeRequest(t, req, http.StatusUnprocessableEntity)
 		expectedAPIError := context.APIError{
 			Message: "sha does not match [given: " + updateFileOptions.SHA + ", expected: " + correctSHA + "]",
 			URL:     setting.API.SwaggerURL,
diff --git a/tests/integration/api_repo_files_change_test.go b/tests/integration/api_repo_files_change_test.go
index 6b1edd047b..1772dec6a6 100644
--- a/tests/integration/api_repo_files_change_test.go
+++ b/tests/integration/api_repo_files_change_test.go
@@ -214,7 +214,7 @@ func TestAPIChangeFiles(t *testing.T) {
 		changeFilesOptions.Files[0].SHA = "badsha"
 		req = NewRequestWithJSON(t, "POST", url, &changeFilesOptions).
 			AddTokenAuth(token2)
-		resp = MakeRequest(t, req, http.StatusConflict)
+		resp = MakeRequest(t, req, http.StatusUnprocessableEntity)
 		expectedAPIError := context.APIError{
 			Message: "sha does not match [given: " + changeFilesOptions.Files[0].SHA + ", expected: " + correctSHA + "]",
 			URL:     setting.API.SwaggerURL,
diff --git a/tests/integration/api_repo_test.go b/tests/integration/api_repo_test.go
index 1c64cc642e..b890f7df43 100644
--- a/tests/integration/api_repo_test.go
+++ b/tests/integration/api_repo_test.go
@@ -376,11 +376,11 @@ func TestAPIRepoMigrate(t *testing.T) {
 		cloneURL, repoName string
 		expectedStatus     int
 	}{
-		{ctxUserID: 1, userID: 2, cloneURL: "https://code.forgejo.org/forgejo/migration-test.git", repoName: "git-admin", expectedStatus: http.StatusCreated},
-		{ctxUserID: 2, userID: 2, cloneURL: "https://code.forgejo.org/forgejo/migration-test.git", repoName: "git-own", expectedStatus: http.StatusCreated},
-		{ctxUserID: 2, userID: 1, cloneURL: "https://code.forgejo.org/forgejo/migration-test.git", repoName: "git-bad", expectedStatus: http.StatusForbidden},
-		{ctxUserID: 2, userID: 3, cloneURL: "https://code.forgejo.org/forgejo/migration-test.git", repoName: "git-org", expectedStatus: http.StatusCreated},
-		{ctxUserID: 2, userID: 6, cloneURL: "https://code.forgejo.org/forgejo/migration-test.git", repoName: "git-bad-org", expectedStatus: http.StatusForbidden},
+		{ctxUserID: 1, userID: 2, cloneURL: "https://github.com/go-gitea/test_repo.git", repoName: "git-admin", expectedStatus: http.StatusCreated},
+		{ctxUserID: 2, userID: 2, cloneURL: "https://github.com/go-gitea/test_repo.git", repoName: "git-own", expectedStatus: http.StatusCreated},
+		{ctxUserID: 2, userID: 1, cloneURL: "https://github.com/go-gitea/test_repo.git", repoName: "git-bad", expectedStatus: http.StatusForbidden},
+		{ctxUserID: 2, userID: 3, cloneURL: "https://github.com/go-gitea/test_repo.git", repoName: "git-org", expectedStatus: http.StatusCreated},
+		{ctxUserID: 2, userID: 6, cloneURL: "https://github.com/go-gitea/test_repo.git", repoName: "git-bad-org", expectedStatus: http.StatusForbidden},
 		{ctxUserID: 2, userID: 3, cloneURL: "https://localhost:3000/user/test_repo.git", repoName: "private-ip", expectedStatus: http.StatusUnprocessableEntity},
 		{ctxUserID: 2, userID: 3, cloneURL: "https://10.0.0.1/user/test_repo.git", repoName: "private-ip", expectedStatus: http.StatusUnprocessableEntity},
 	}
@@ -396,7 +396,20 @@ func TestAPIRepoMigrate(t *testing.T) {
 			RepoName:    testCase.repoName,
 		}).AddTokenAuth(token)
 		resp := MakeRequest(t, req, NoExpectedStatus)
-		require.Equalf(t, testCase.expectedStatus, resp.Code, "unexpected status (may be due to throttling): '%v' on url '%s'", resp.Body.String(), testCase.cloneURL)
+		if resp.Code == http.StatusUnprocessableEntity {
+			respJSON := map[string]string{}
+			DecodeJSON(t, resp, &respJSON)
+			switch respJSON["message"] {
+			case "Remote visit addressed rate limitation.":
+				t.Log("test hit github rate limitation")
+			case "You can not import from disallowed hosts.":
+				assert.Equal(t, "private-ip", testCase.repoName)
+			default:
+				assert.FailNow(t, "unexpected error", "'%v' on url '%s'", respJSON["message"], testCase.cloneURL)
+			}
+		} else {
+			assert.Equal(t, testCase.expectedStatus, resp.Code)
+		}
 	}
 }
 
@@ -420,7 +433,7 @@ func testAPIRepoMigrateConflict(t *testing.T, u *url.URL) {
 		require.NoError(t, err)
 		userID := user.ID
 
-		cloneURL := "https://code.forgejo.org/forgejo/migration-test.git"
+		cloneURL := "https://github.com/go-gitea/test_repo.git"
 
 		req := NewRequestWithJSON(t, "POST", "/api/v1/repos/migrate",
 			&api.MigrateRepoOptions{
diff --git a/tests/integration/pull_review_test.go b/tests/integration/pull_review_test.go
index 0c05b3da37..ed3d3baaf4 100644
--- a/tests/integration/pull_review_test.go
+++ b/tests/integration/pull_review_test.go
@@ -6,7 +6,6 @@ package integration
 
 import (
 	"fmt"
-	"io"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -20,7 +19,6 @@ import (
 	repo_model "forgejo.org/models/repo"
 	"forgejo.org/models/unittest"
 	user_model "forgejo.org/models/user"
-	"forgejo.org/modules/git"
 	"forgejo.org/modules/gitrepo"
 	repo_module "forgejo.org/modules/repository"
 	"forgejo.org/modules/test"
@@ -95,9 +93,16 @@ func TestPullView_SelfReviewNotification(t *testing.T) {
 		require.NoError(t, err)
 
 		// create a new branch to prepare for pull request
-		err = updateFileInBranch(user2, repo, "README.md", "codeowner-basebranch",
-			strings.NewReader("# This is a new project\n"),
-		)
+		_, err = files_service.ChangeRepoFiles(db.DefaultContext, repo, user2, &files_service.ChangeRepoFilesOptions{
+			NewBranch: "codeowner-basebranch",
+			Files: []*files_service.ChangeRepoFile{
+				{
+					Operation:     "update",
+					TreePath:      "README.md",
+					ContentReader: strings.NewReader("# This is a new project\n"),
+				},
+			},
+		})
 		require.NoError(t, err)
 
 		// Create a pull request.
@@ -361,9 +366,16 @@ func TestPullView_CodeOwner(t *testing.T) {
 			defer tests.PrintCurrentTest(t)()
 
 			// create a new branch to prepare for pull request
-			err := updateFileInBranch(user2, repo, "README.md", "codeowner-basebranch",
-				strings.NewReader("# This is a new project\n"),
-			)
+			_, err := files_service.ChangeRepoFiles(db.DefaultContext, repo, user2, &files_service.ChangeRepoFilesOptions{
+				NewBranch: "codeowner-basebranch",
+				Files: []*files_service.ChangeRepoFile{
+					{
+						Operation:     "update",
+						TreePath:      "README.md",
+						ContentReader: strings.NewReader("# This is a new project\n"),
+					},
+				},
+			})
 			require.NoError(t, err)
 
 			// Create a pull request.
@@ -388,18 +400,31 @@ func TestPullView_CodeOwner(t *testing.T) {
 		})
 
 		// change the default branch CODEOWNERS file to change README.md's codeowner
-		err := updateFileInBranch(user2, repo, "CODEOWNERS", "",
-			strings.NewReader("README.md @user8\n"),
-		)
+		_, err := files_service.ChangeRepoFiles(db.DefaultContext, repo, user2, &files_service.ChangeRepoFilesOptions{
+			Files: []*files_service.ChangeRepoFile{
+				{
+					Operation:     "update",
+					TreePath:      "CODEOWNERS",
+					ContentReader: strings.NewReader("README.md @user8\n"),
+				},
+			},
+		})
 		require.NoError(t, err)
 
 		t.Run("Second Pull Request", func(t *testing.T) {
 			defer tests.PrintCurrentTest(t)()
 
 			// create a new branch to prepare for pull request
-			err := updateFileInBranch(user2, repo, "README.md", "codeowner-basebranch2",
-				strings.NewReader("# This is a new project2\n"),
-			)
+			_, err = files_service.ChangeRepoFiles(db.DefaultContext, repo, user2, &files_service.ChangeRepoFilesOptions{
+				NewBranch: "codeowner-basebranch2",
+				Files: []*files_service.ChangeRepoFile{
+					{
+						Operation:     "update",
+						TreePath:      "README.md",
+						ContentReader: strings.NewReader("# This is a new project2\n"),
+					},
+				},
+			})
 			require.NoError(t, err)
 
 			// Create a pull request.
@@ -421,9 +446,16 @@ func TestPullView_CodeOwner(t *testing.T) {
 			require.NoError(t, err)
 
 			// create a new branch to prepare for pull request
-			err = updateFileInBranch(user5, forkedRepo, "README.md", "codeowner-basebranch-forked",
-				strings.NewReader("# This is a new forked project\n"),
-			)
+			_, err = files_service.ChangeRepoFiles(db.DefaultContext, forkedRepo, user5, &files_service.ChangeRepoFilesOptions{
+				NewBranch: "codeowner-basebranch-forked",
+				Files: []*files_service.ChangeRepoFile{
+					{
+						Operation:     "update",
+						TreePath:      "README.md",
+						ContentReader: strings.NewReader("# This is a new forked project\n"),
+					},
+				},
+			})
 			require.NoError(t, err)
 
 			session := loginUser(t, "user5")
@@ -730,32 +762,3 @@ func TestPullRequestReplyMail(t *testing.T) {
 		})
 	})
 }
-
-func updateFileInBranch(user *user_model.User, repo *repo_model.Repository, treePath, newBranch string, content io.ReadSeeker) error {
-	oldBranch, err := gitrepo.GetDefaultBranch(git.DefaultContext, repo)
-	if err != nil {
-		return err
-	}
-
-	commitID, err := gitrepo.GetBranchCommitID(git.DefaultContext, repo, oldBranch)
-	if err != nil {
-		return err
-	}
-
-	opts := &files_service.ChangeRepoFilesOptions{
-		Files: []*files_service.ChangeRepoFile{
-			{
-				Operation:     "update",
-				TreePath:      treePath,
-				ContentReader: content,
-			},
-		},
-		OldBranch:    oldBranch,
-		NewBranch:    newBranch,
-		Author:       nil,
-		Committer:    nil,
-		LastCommitID: commitID,
-	}
-	_, err = files_service.ChangeRepoFiles(git.DefaultContext, repo, user, opts)
-	return err
-}
diff --git a/tests/integration/repofiles_change_test.go b/tests/integration/repofiles_change_test.go
index 42d47c4591..b993fdf936 100644
--- a/tests/integration/repofiles_change_test.go
+++ b/tests/integration/repofiles_change_test.go
@@ -294,30 +294,6 @@ func TestChangeRepoFiles(t *testing.T) {
 			assert.Equal(t, expectedFileResponse.Commit.Author.Name, filesResponse.Commit.Author.Name)
 		})
 
-		t.Run("Update with commit ID (without blob sha)", func(t *testing.T) {
-			defer tests.PrintCurrentTest(t)()
-			opts := getUpdateRepoFilesOptions(repo)
-
-			commit, err := gitRepo.GetBranchCommit(opts.NewBranch)
-			require.NoError(t, err)
-
-			opts.Files[0].SHA = ""
-			opts.LastCommitID = commit.ID.String()
-			filesResponse, err := files_service.ChangeRepoFiles(git.DefaultContext, repo, doer, opts)
-			require.NoError(t, err)
-
-			commit, err = gitRepo.GetBranchCommit(opts.NewBranch)
-			require.NoError(t, err)
-			lastCommit, err := commit.GetCommitByPath(opts.Files[0].TreePath)
-			require.NoError(t, err)
-			expectedFileResponse := getExpectedFileResponseForRepofilesUpdate(commit.ID.String(), opts.Files[0].TreePath, lastCommit.ID.String(), lastCommit.Committer.When)
-			assert.Equal(t, expectedFileResponse.Content, filesResponse.Files[0])
-			assert.Equal(t, expectedFileResponse.Commit.SHA, filesResponse.Commit.SHA)
-			assert.Equal(t, expectedFileResponse.Commit.HTMLURL, filesResponse.Commit.HTMLURL)
-			assert.Equal(t, expectedFileResponse.Commit.Author.Email, filesResponse.Commit.Author.Email)
-			assert.Equal(t, expectedFileResponse.Commit.Author.Name, filesResponse.Commit.Author.Name)
-		})
-
 		t.Run("Update and move", func(t *testing.T) {
 			defer tests.PrintCurrentTest(t)()
 			opts := getUpdateRepoFilesOptions(repo)
@@ -439,26 +415,6 @@ func TestChangeRepoFilesErrors(t *testing.T) {
 			assert.EqualError(t, err, expectedError)
 		})
 
-		t.Run("missing SHA", func(t *testing.T) {
-			opts := getUpdateRepoFilesOptions(repo)
-			opts.Files[0].SHA = ""
-			filesResponse, err := files_service.ChangeRepoFiles(git.DefaultContext, repo, doer, opts)
-			assert.Nil(t, filesResponse)
-			require.Error(t, err)
-			expectedError := "a SHA or commit ID must be provided when updating a file"
-			assert.EqualError(t, err, expectedError)
-		})
-
-		t.Run("bad last commit ID", func(t *testing.T) {
-			opts := getUpdateRepoFilesOptions(repo)
-			opts.LastCommitID = "bad"
-			filesResponse, err := files_service.ChangeRepoFiles(git.DefaultContext, repo, doer, opts)
-			assert.Nil(t, filesResponse)
-			require.Error(t, err)
-			expectedError := "ConvertToSHA1: Invalid last commit ID: object does not exist [id: bad, rel_path: ]"
-			assert.EqualError(t, err, expectedError)
-		})
-
 		t.Run("new branch already exists", func(t *testing.T) {
 			opts := getUpdateRepoFilesOptions(repo)
 			opts.NewBranch = "develop"
diff --git a/tests/test_utils.go b/tests/test_utils.go
index 75d1f98914..66da5e6bea 100644
--- a/tests/test_utils.go
+++ b/tests/test_utils.go
@@ -24,7 +24,6 @@ import (
 	user_model "forgejo.org/models/user"
 	"forgejo.org/modules/base"
 	"forgejo.org/modules/git"
-	"forgejo.org/modules/gitrepo"
 	"forgejo.org/modules/graceful"
 	"forgejo.org/modules/log"
 	"forgejo.org/modules/optional"
@@ -409,9 +408,6 @@ func CreateDeclarativeRepoWithOptions(t *testing.T, owner *user_model.User, opts
 		assert.True(t, autoInit, "Files cannot be specified if AutoInit is disabled")
 		files := opts.Files.Value()
 
-		commitID, err := gitrepo.GetBranchCommitID(git.DefaultContext, repo, "main")
-		require.NoError(t, err)
-
 		resp, err := files_service.ChangeRepoFiles(git.DefaultContext, repo, owner, &files_service.ChangeRepoFilesOptions{
 			Files:     files,
 			Message:   "add files",
@@ -429,7 +425,6 @@ func CreateDeclarativeRepoWithOptions(t *testing.T, owner *user_model.User, opts
 				Author:    time.Now(),
 				Committer: time.Now(),
 			},
-			LastCommitID: commitID,
 		})
 		require.NoError(t, err)
 		assert.NotEmpty(t, resp)