Convert `<div class="button">` to `<button class="button">` (#23337)

This improves a lot of accessibility shortcomings.
Every possible instance of `<div class="button">` matching the command
`ag '<[^ab].*?class=.*?[" ]button[ "]' templates/ | grep -v 'dropdown'`
has been converted when possible.
divs with the `dropdown` class and their children were omitted as
1. more analysis must be conducted whether the dropdowns still work as
intended when they are a `button` instead of a `div`.
2. most dropdowns have `div`s as children. The HTML standard disallows
`div`s inside `button`s.
3. When a dropdown child that's part of the displayed text content is
converted to a `button`, the dropdown can be focused twice

Further changes include that all "gitea-managed" buttons with JS code
received an `e.preventDefault()` so that they don't accidentally submit
an underlying form, which would execute instead of cancel the action.
Lastly, some minor issues were fixed as well during the refactoring.

## Future improvements

As mentioned in
https://github.com/go-gitea/gitea/pull/23337#discussion_r1127277391,
`<a>`s without `href` attribute are not focusable.
They should later on be converted to `<button>`s.

---------

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

12 files changed, 43 insertions, 61 deletions

diff --git a/templates/repo/issue/labels.tmpl b/templates/repo/issue/labels.tmpl
index 82cfcd0712..0a25d9c87f 100644
--- a/templates/repo/issue/labels.tmpl
+++ b/templates/repo/issue/labels.tmpl
@@ -6,7 +6,7 @@
 			{{template "repo/issue/navbar" .}}
 			{{if and (or .CanWriteIssues .CanWritePulls) (not .Repository.IsArchived)}}
 				<div class="ui right">
-					<div class="ui green new-label button">{{.locale.Tr "repo.issues.new_label"}}</div>
+					<button class="ui green new-label button">{{.locale.Tr "repo.issues.new_label"}}</button>
 				</div>
 			{{end}}
 		</div>
diff --git a/templates/repo/issue/labels/edit_delete_label.tmpl b/templates/repo/issue/labels/edit_delete_label.tmpl
index 450061e835..38a948172f 100644
--- a/templates/repo/issue/labels/edit_delete_label.tmpl
+++ b/templates/repo/issue/labels/edit_delete_label.tmpl
@@ -6,16 +6,7 @@
 	<div class="content">
 		<p>{{.locale.Tr "repo.issues.label_deletion_desc"}}</p>
 	</div>
-	<div class="actions">
-		<div class="ui red basic inverted cancel button">
-			<i class="remove icon"></i>
-			{{.locale.Tr "modal.no"}}
-		</div>
-		<div class="ui green basic inverted ok button">
-			<i class="checkmark icon"></i>
-			{{.locale.Tr "modal.yes"}}
-		</div>
-	</div>
+	{{template "base/delete_modal_actions" .}}
 </div>
 
 <div class="ui small edit-label modal">
@@ -61,11 +52,13 @@
 		</form>
 	</div>
 	<div class="actions">
-		<div class="ui secondary small basic cancel button">
+		<button class="ui secondary small basic cancel button">
+			{{svg "octicon-x"}}
 			{{.locale.Tr "cancel"}}
-		</div>
-		<div class="ui primary small approve button">
+		</button>
+		<button class="ui primary small approve button">
+			<i class="save icon"></i>
 			{{.locale.Tr "save"}}
-		</div>
+		</button>
 	</div>
 </div>
diff --git a/templates/repo/issue/labels/label_new.tmpl b/templates/repo/issue/labels/label_new.tmpl
index 62f7155b74..c937f28e8a 100644
--- a/templates/repo/issue/labels/label_new.tmpl
+++ b/templates/repo/issue/labels/label_new.tmpl
@@ -36,12 +36,15 @@
 			</div>
 		</form>
 	</div>
+
 	<div class="actions">
-		<div class="ui secondary small basic cancel button">
+		<button class="ui red basic inverted cancel button">
+			{{svg "octicon-x"}}
 			{{.locale.Tr "cancel"}}
-		</div>
-		<div class="ui primary small approve button">
+		</button>
+		<button class="ui green basic inverted ok button">
+			{{svg "octicon-check"}}
 			{{.locale.Tr "repo.issues.create_label"}}
-		</div>
+		</button>
 	</div>
 </div>
diff --git a/templates/repo/issue/list.tmpl b/templates/repo/issue/list.tmpl
index ca05264e77..36faf86113 100644
--- a/templates/repo/issue/list.tmpl
+++ b/templates/repo/issue/list.tmpl
@@ -213,9 +213,9 @@
 					{{if not .Repository.IsArchived}}
 					<!-- Action Button -->
 					{{if .IsShowClosed}}
-						<div class="ui green active basic button issue-action" data-action="open" data-url="{{$.RepoLink}}/issues/status" style="margin-left: auto">{{.locale.Tr "repo.issues.action_open"}}</div>
+						<button class="ui green active basic button issue-action" data-action="open" data-url="{{$.RepoLink}}/issues/status" style="margin-left: auto">{{.locale.Tr "repo.issues.action_open"}}</button>
 					{{else}}
-						<div class="ui red active basic button issue-action" data-action="close" data-url="{{$.RepoLink}}/issues/status" style="margin-left: auto">{{.locale.Tr "repo.issues.action_close"}}</div>
+						<button class="ui red active basic button issue-action" data-action="close" data-url="{{$.RepoLink}}/issues/status" style="margin-left: auto">{{.locale.Tr "repo.issues.action_close"}}</button>
 					{{end}}
 					<!-- Labels -->
 					<div class="ui {{if not .Labels}}disabled{{end}} dropdown jump item">
diff --git a/templates/repo/issue/milestone_issues.tmpl b/templates/repo/issue/milestone_issues.tmpl
index 2918c4359f..b4f036d32a 100644
--- a/templates/repo/issue/milestone_issues.tmpl
+++ b/templates/repo/issue/milestone_issues.tmpl
@@ -149,9 +149,9 @@
 				<div class="ui secondary filter stackable menu">
 					<!-- Action Button -->
 					{{if .IsShowClosed}}
-						<div class="ui green active basic button issue-action" data-action="open" data-url="{{$.RepoLink}}/issues/status" style="margin-left: auto">{{.locale.Tr "repo.issues.action_open"}}</div>
+						<button class="ui green active basic button issue-action" data-action="open" data-url="{{$.RepoLink}}/issues/status" style="margin-left: auto">{{.locale.Tr "repo.issues.action_open"}}</button>
 					{{else}}
-						<div class="ui red active basic button issue-action" data-action="close" data-url="{{$.RepoLink}}/issues/status" style="margin-left: auto">{{.locale.Tr "repo.issues.action_close"}}</div>
+						<button class="ui red active basic button issue-action" data-action="close" data-url="{{$.RepoLink}}/issues/status" style="margin-left: auto">{{.locale.Tr "repo.issues.action_close"}}</button>
 					{{end}}
 					<!-- Labels -->
 					<div class="ui {{if not .Labels}}disabled{{end}} dropdown jump item">
diff --git a/templates/repo/issue/milestones.tmpl b/templates/repo/issue/milestones.tmpl
index 3730d3d3c4..5797b358f7 100644
--- a/templates/repo/issue/milestones.tmpl
+++ b/templates/repo/issue/milestones.tmpl
@@ -124,16 +124,7 @@
 		<div class="content">
 			<p>{{.locale.Tr "repo.milestones.deletion_desc"}}</p>
 		</div>
-		<div class="actions">
-			<div class="ui red basic inverted cancel button">
-				<i class="remove icon"></i>
-				{{.locale.Tr "modal.no"}}
-			</div>
-			<div class="ui green basic inverted ok button">
-				<i class="checkmark icon"></i>
-				{{.locale.Tr "modal.yes"}}
-			</div>
-		</div>
+		{{template "base/delete_modal_actions" .}}
 	</div>
 {{end}}
 {{template "base/footer" .}}
diff --git a/templates/repo/issue/view_content.tmpl b/templates/repo/issue/view_content.tmpl
index 6aec6e3157..f013317ca8 100644
--- a/templates/repo/issue/view_content.tmpl
+++ b/templates/repo/issue/view_content.tmpl
@@ -112,13 +112,13 @@
 								<div class="text right">
 									{{if and (or .HasIssuesOrPullsWritePermission .IsIssuePoster) (not .DisableStatusChange)}}
 										{{if .Issue.IsClosed}}
-											<div id="status-button" class="ui green basic button" tabindex="6" data-status="{{.locale.Tr "repo.issues.reopen_issue"}}" data-status-and-comment="{{.locale.Tr "repo.issues.reopen_comment_issue"}}" data-status-val="reopen">
+											<button id="status-button" class="ui green basic button" tabindex="6" data-status="{{.locale.Tr "repo.issues.reopen_issue"}}" data-status-and-comment="{{.locale.Tr "repo.issues.reopen_comment_issue"}}" data-status-val="reopen">
 												{{.locale.Tr "repo.issues.reopen_issue"}}
-											</div>
+											</button>
 										{{else}}
-											<div id="status-button" class="ui red basic button" tabindex="6" data-status="{{.locale.Tr "repo.issues.close_issue"}}" data-status-and-comment="{{.locale.Tr "repo.issues.close_comment_issue"}}" data-status-val="close">
+											<button id="status-button" class="ui red basic button" tabindex="6" data-status="{{.locale.Tr "repo.issues.close_issue"}}" data-status-and-comment="{{.locale.Tr "repo.issues.close_comment_issue"}}" data-status-val="close">
 												{{.locale.Tr "repo.issues.close_issue"}}
-											</div>
+											</button>
 										{{end}}
 									{{end}}
 									<button class="ui green button loading-button" tabindex="5">
@@ -163,13 +163,13 @@
 									<div class="text right">
 										{{if and (or .HasIssuesOrPullsWritePermission .IsIssuePoster) (not .DisableStatusChange)}}
 											{{if .Issue.IsClosed}}
-												<div id="status-button" class="ui green basic button" tabindex="6" data-status="{{.locale.Tr "repo.issues.reopen_issue"}}" data-status-and-comment="{{.locale.Tr "repo.issues.reopen_comment_issue"}}" data-status-val="reopen">
+												<button id="status-button" class="ui green basic button" tabindex="6" data-status="{{.locale.Tr "repo.issues.reopen_issue"}}" data-status-and-comment="{{.locale.Tr "repo.issues.reopen_comment_issue"}}" data-status-val="reopen">
 													{{.locale.Tr "repo.issues.reopen_issue"}}
-												</div>
+												</button>
 											{{else}}
-												<div id="status-button" class="ui red basic button" tabindex="6" data-status="{{.locale.Tr "repo.issues.close_issue"}}" data-status-and-comment="{{.locale.Tr "repo.issues.close_comment_issue"}}" data-status-val="close">
+												<button id="status-button" class="ui red basic button" tabindex="6" data-status="{{.locale.Tr "repo.issues.close_issue"}}" data-status-and-comment="{{.locale.Tr "repo.issues.close_comment_issue"}}" data-status-val="close">
 													{{.locale.Tr "repo.issues.close_issue"}}
-												</div>
+												</button>
 											{{end}}
 										{{end}}
 										<button class="ui green button loading-button" tabindex="5">
@@ -215,8 +215,8 @@
 		{{end}}
 		<div class="field footer">
 			<div class="text right edit">
-				<div class="ui basic secondary cancel button" tabindex="3">{{.locale.Tr "repo.issues.cancel"}}</div>
-				<div class="ui primary save button" tabindex="2">{{.locale.Tr "repo.issues.save"}}</div>
+				<button class="ui basic secondary cancel button" tabindex="3">{{.locale.Tr "repo.issues.cancel"}}</button>
+				<button class="ui primary save button" tabindex="2">{{.locale.Tr "repo.issues.save"}}</button>
 			</div>
 		</div>
 	</div>
diff --git a/templates/repo/issue/view_content/comments_delete_time.tmpl b/templates/repo/issue/view_content/comments_delete_time.tmpl
index bc08d7fde7..b79b7ae2be 100644
--- a/templates/repo/issue/view_content/comments_delete_time.tmpl
+++ b/templates/repo/issue/view_content/comments_delete_time.tmpl
@@ -7,10 +7,7 @@
 						{{.ctxData.CsrfTokenHtml}}
 					</form>
 					<div class="header">{{.ctxData.locale.Tr "repo.issues.del_time"}}</div>
-					<div class="actions">
-						<div class="ui red approve button">{{.ctxData.locale.Tr "repo.issues.context.delete"}}</div>
-						<div class="ui cancel button">{{.ctxData.locale.Tr "repo.issues.add_time_cancel"}}</div>
-					</div>
+					{{template "base/delete_modal_actions" .}}
 				</div>
 				<button class="ui icon button compact mini issue-delete-time tooltip" data-id="{{.comment.Time.ID}}" data-content="{{.ctxData.locale.Tr "repo.issues.del_time"}}" data-position="top right">
 					{{svg "octicon-trash"}}
diff --git a/templates/repo/issue/view_content/pull.tmpl b/templates/repo/issue/view_content/pull.tmpl
index f0bf23c9e9..30345b0138 100644
--- a/templates/repo/issue/view_content/pull.tmpl
+++ b/templates/repo/issue/view_content/pull.tmpl
@@ -58,7 +58,7 @@
 												<input id="message" name="message">
 											</div>
 											<div class="text right actions">
-												<div class="ui cancel button">{{$.locale.Tr "settings.cancel"}}</div>
+												<button class="ui cancel button">{{$.locale.Tr "settings.cancel"}}</button>
 												<button class="ui red button" type="submit">{{$.locale.Tr "ok"}}</button>
 											</div>
 										</form>
diff --git a/templates/repo/issue/view_content/sidebar.tmpl b/templates/repo/issue/view_content/sidebar.tmpl
index e58f94aff3..165dca7e0c 100644
--- a/templates/repo/issue/view_content/sidebar.tmpl
+++ b/templates/repo/issue/view_content/sidebar.tmpl
@@ -346,8 +346,8 @@
 									</form>
 								</div>
 								<div class="actions">
-									<div class="ui green approve button">{{.locale.Tr "repo.issues.add_time_short"}}</div>
-									<div class="ui red cancel button">{{.locale.Tr "repo.issues.add_time_cancel"}}</div>
+									<button class="ui green approve button">{{.locale.Tr "repo.issues.add_time_short"}}</button>
+									<button class="ui red cancel button">{{.locale.Tr "repo.issues.add_time_cancel"}}</button>
 								</div>
 							</div>
 							<button class="ui fluid button green tooltip issue-add-time gt-mt-3" data-content='{{.locale.Tr "repo.issues.add_time"}}' data-position="top center">{{.locale.Tr "repo.issues.add_time_short"}}</button>
@@ -532,14 +532,14 @@
 						{{end}}</p>
 					</div>
 					<div class="actions">
-						<div class="ui red cancel inverted button">
+						<button class="ui red cancel inverted button">
 							{{svg "octicon-x"}}
 							{{.locale.Tr "repo.issues.dependency.cancel"}}
-						</div>
-						<div class="ui green ok inverted button">
+						</button>
+						<button class="ui green ok inverted button">
 							{{svg "octicon-check"}}
 							{{.locale.Tr "repo.issues.dependency.remove"}}
-						</div>
+						</button>
 					</div>
 				</div>
 			{{end}}
@@ -619,7 +619,7 @@
 						{{end}}
 
 						<div class="text right actions">
-							<div class="ui cancel button">{{.locale.Tr "settings.cancel"}}</div>
+							<button class="ui cancel button">{{.locale.Tr "settings.cancel"}}</button>
 							<button class="ui red button">
 								{{if .Issue.IsLocked}}
 									{{.locale.Tr "repo.issues.unlock_confirm"}}
@@ -655,7 +655,7 @@
 				<form action="{{.Issue.Link}}/delete" method="post">
 					{{.CsrfTokenHtml}}
 					<div class="center actions">
-						<div class="ui basic cancel inverted button">{{.locale.Tr "settings.cancel"}}</div>
+						<button class="ui basic cancel inverted button">{{.locale.Tr "settings.cancel"}}</button>
 						<button class="ui basic red inverted button">{{.locale.Tr "modal.yes"}}</button>
 					</div>
 				</form>
diff --git a/templates/repo/issue/view_content/update_branch_by_merge.tmpl b/templates/repo/issue/view_content/update_branch_by_merge.tmpl
index 6d36a9b45f..49e4467dc3 100644
--- a/templates/repo/issue/view_content/update_branch_by_merge.tmpl
+++ b/templates/repo/issue/view_content/update_branch_by_merge.tmpl
@@ -19,8 +19,8 @@
 						<div class="ui dropdown icon button no-text">
 							{{svg "octicon-triangle-down" 14 "dropdown icon"}}
 							<div class="menu">
-								<div class="item active selected" data-do="{{.Link}}/update">{{$.locale.Tr "repo.pulls.update_branch"}}</div>
-								<div class="item" data-do="{{.Link}}/update?style=rebase">{{$.locale.Tr "repo.pulls.update_branch_rebase"}}</div>
+								<a class="item active selected" data-do="{{.Link}}/update">{{$.locale.Tr "repo.pulls.update_branch"}}</a>
+								<a class="item" data-do="{{.Link}}/update?style=rebase">{{$.locale.Tr "repo.pulls.update_branch_rebase"}}</a>
 							</div>
 						</div>
 					</div>
diff --git a/templates/repo/issue/view_title.tmpl b/templates/repo/issue/view_title.tmpl
index f0ac1e021e..2a8381b0b4 100644
--- a/templates/repo/issue/view_title.tmpl
+++ b/templates/repo/issue/view_title.tmpl
@@ -1,9 +1,7 @@
 <div class="sixteen wide column title">
 	<div class="issue-title" id="issue-title-wrapper">
 		{{if and (or .HasIssuesOrPullsWritePermission .IsIssuePoster) (not .Repository.IsArchived)}}
-			<div class="edit-button">
-				<button id="edit-title" class="ui basic button secondary not-in-edit">{{.locale.Tr "repo.issues.edit"}}</button>
-			</div>
+			<button id="edit-title" class="ui basic button secondary edit-button not-in-edit">{{.locale.Tr "repo.issues.edit"}}</button>
 		{{end}}
 		<h1>
 			<span id="issue-title">{{RenderIssueTitle $.Context .Issue.Title $.RepoLink $.Repository.ComposeMetas | RenderCodeBlock}}</span>