[GITEA] Allow user to select email for file operations in Web UI

- Add a dropdown to the web interface for changing files to select which
Email should be used for the commit. It only shows (and verifies) that a
activated mail can be used, while this isn't necessary, it's better to
have this already in place.
- Added integration testing.
- Resolves https://codeberg.org/forgejo/forgejo/issues/281

(cherry picked from commit 564e701f40)
(cherry picked from commit de8f2e03cc)
(cherry picked from commit 0182cff12e)
(cherry picked from commit 9c74254d46)
(cherry picked from commit 2f0b68f821)
(cherry picked from commit 079b995d49)

routers/web/repo/editor.go

@@ -14,6 +14,7 @@ import (
 	git_model "code.gitea.io/gitea/models/git"
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unit"
+	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/charset"
 	"code.gitea.io/gitea/modules/context"
@@ -99,6 +100,27 @@ func getParentTreeFields(treePath string) (treeNames, treePaths []string) {
 	return treeNames, treePaths
 }
 
+// getSelectableEmailAddresses returns which emails can be used by the user as
+// email for a Git commiter.
+func getSelectableEmailAddresses(ctx *context.Context) ([]*user_model.ActivatedEmailAddress, error) {
+	// Retrieve emails that the user could use for commiter identity.
+	commitEmails, err := user_model.GetActivatedEmailAddresses(ctx, ctx.Doer.ID)
+	if err != nil {
+		return nil, fmt.Errorf("GetActivatedEmailAddresses: %w", err)
+	}
+
+	// Allow for the placeholder mail to be used. Use -1 as ID to identify
+	// this entry to be the placerholder mail of the user.
+	placeholderMail := &user_model.ActivatedEmailAddress{ID: -1, Email: ctx.Doer.GetPlaceholderEmail()}
+	if ctx.Doer.KeepEmailPrivate {
+		commitEmails = append([]*user_model.ActivatedEmailAddress{placeholderMail}, commitEmails...)
+	} else {
+		commitEmails = append(commitEmails, placeholderMail)
+	}
+
+	return commitEmails, nil
+}
+
 func editFile(ctx *context.Context, isNewFile bool) {
 	ctx.Data["PageIsEdit"] = true
 	ctx.Data["IsNewFile"] = isNewFile
@@ -177,6 +199,12 @@ func editFile(ctx *context.Context, isNewFile bool) {
 		treeNames = append(treeNames, fileName)
 	}
 
+	commitEmails, err := getSelectableEmailAddresses(ctx)
+	if err != nil {
+		ctx.ServerError("getSelectableEmailAddresses", err)
+		return
+	}
+
 	ctx.Data["TreeNames"] = treeNames
 	ctx.Data["TreePaths"] = treePaths
 	ctx.Data["BranchLink"] = ctx.Repo.RepoLink + "/src/" + ctx.Repo.BranchNameSubURL()
@@ -192,6 +220,8 @@ func editFile(ctx *context.Context, isNewFile bool) {
 	ctx.Data["PreviewableExtensions"] = strings.Join(markup.PreviewableExtensions(), ",")
 	ctx.Data["LineWrapExtensions"] = strings.Join(setting.Repository.Editor.LineWrapExtensions, ",")
 	ctx.Data["EditorconfigJson"] = GetEditorConfig(ctx, treePath)
+	ctx.Data["CommitMails"] = commitEmails
+	ctx.Data["DefaultCommitMail"] = ctx.Doer.GetEmail()
 
 	ctx.HTML(http.StatusOK, tplEditFile)
 }
@@ -227,6 +257,12 @@ func editFilePost(ctx *context.Context, form forms.EditRepoFileForm, isNewFile b
 		branchName = form.NewBranchName
 	}
 
+	commitEmails, err := getSelectableEmailAddresses(ctx)
+	if err != nil {
+		ctx.ServerError("getSelectableEmailAddresses", err)
+		return
+	}
+
 	ctx.Data["PageIsEdit"] = true
 	ctx.Data["PageHasPosted"] = true
 	ctx.Data["IsNewFile"] = isNewFile
@@ -243,6 +279,8 @@ func editFilePost(ctx *context.Context, form forms.EditRepoFileForm, isNewFile b
 	ctx.Data["PreviewableExtensions"] = strings.Join(markup.PreviewableExtensions(), ",")
 	ctx.Data["LineWrapExtensions"] = strings.Join(setting.Repository.Editor.LineWrapExtensions, ",")
 	ctx.Data["EditorconfigJson"] = GetEditorConfig(ctx, form.TreePath)
+	ctx.Data["CommitMails"] = commitEmails
+	ctx.Data["DefaultCommitMail"] = ctx.Doer.GetEmail()
 
 	if ctx.HasError() {
 		ctx.HTML(http.StatusOK, tplEditFile)
@@ -277,6 +315,30 @@ func editFilePost(ctx *context.Context, form forms.EditRepoFileForm, isNewFile b
 		operation = "create"
 	}
 
+	gitIdentity := &files_service.IdentityOptions{
+		Name: ctx.Doer.Name,
+	}
+
+	// -1 is defined as placeholder email.
+	if form.CommitMailID == -1 {
+		gitIdentity.Email = ctx.Doer.GetPlaceholderEmail()
+	} else {
+		// Check if the given email is activated.
+		email, err := user_model.GetEmailAddressByID(ctx, ctx.Doer.ID, form.CommitMailID)
+		if err != nil {
+			ctx.ServerError("GetEmailAddressByID", err)
+			return
+		}
+
+		if email == nil || !email.IsActivated {
+			ctx.Data["Err_CommitMailID"] = true
+			ctx.RenderWithErr(ctx.Tr("repo.editor.invalid_commit_mail"), tplEditFile, &form)
+			return
+		}
+
+		gitIdentity.Email = email.Email
+	}
+
 	if _, err := files_service.ChangeRepoFiles(ctx, ctx.Repo.Repository, ctx.Doer, &files_service.ChangeRepoFilesOptions{
 		LastCommitID: form.LastCommit,
 		OldBranch:    ctx.Repo.BranchName,
@@ -290,7 +352,9 @@ func editFilePost(ctx *context.Context, form forms.EditRepoFileForm, isNewFile b
 				ContentReader: strings.NewReader(strings.ReplaceAll(form.Content, "\r", "")),
 			},
 		},
-		Signoff: form.Signoff,
+		Signoff:   form.Signoff,
+		Author:    gitIdentity,
+		Committer: gitIdentity,
 	}); err != nil {
 		// This is where we handle all the errors thrown by files_service.ChangeRepoFiles
 		if git.IsErrNotExist(err) {