Show outdated comments in files changed tab (#24936)

If enabled show a clickable label in the comment. A click on the label
opens the Conversation tab with the comment focussed - there you're able
to view the old diff (or original diff the comment was created on).

**Screenshots**


![image](https://github.com/go-gitea/gitea/assets/1135157/63ab9571-a9ee-4900-9f02-94ab0095f9e7)

![image](https://github.com/go-gitea/gitea/assets/1135157/78f7c225-8d76-46f5-acfd-9b8aab988a6c)



When resolved and outdated:

![image](https://github.com/go-gitea/gitea/assets/1135157/6ece9ebd-c792-4aa5-9c35-628694e9d093)

Option to enable/disable this (stored in user settings - default is
disabled):

![image](https://github.com/go-gitea/gitea/assets/1135157/ed99dfe4-76dc-4c12-bd96-e7e62da50ab5)

![image](https://github.com/go-gitea/gitea/assets/1135157/e837a052-e92e-4a28-906d-9db5bacf93a6)



fixes #24913

---------

Co-authored-by: silverwind <me@silverwind.io>

4 files changed, 39 insertions, 7 deletions

diff --git a/templates/repo/diff/comments.tmpl b/templates/repo/diff/comments.tmpl
index 5b0b32cc97..d19ac1f047 100644
--- a/templates/repo/diff/comments.tmpl
+++ b/templates/repo/diff/comments.tmpl
@@ -31,6 +31,12 @@
 				{{end}}
 			</div>
 			<div class="comment-header-right actions gt-df gt-ac">
+				{{if .Invalidated}}
+					{{$referenceUrl := printf "%s#%s" $.root.Issue.Link .HashTag}}
+					<a href="{{AppSubUrl}}{{$referenceUrl}}" class="ui label basic small" data-tooltip-content="{{$.root.locale.Tr "repo.issues.review.outdated_description"}}">
+						{{$.root.locale.Tr "repo.issues.review.outdated"}}
+					</a>
+				{{end}}
 				{{if and .Review}}
 					{{if eq .Review.Type 0}}
 						<div class="ui label basic small yellow pending-label" data-tooltip-content="{{$.root.locale.Tr "repo.issues.review.pending.tooltip" ($.root.locale.Tr "repo.diff.review") ($.root.locale.Tr "repo.diff.review.approve") ($.root.locale.Tr "repo.diff.review.comment") ($.root.locale.Tr "repo.diff.review.reject")}}">
diff --git a/templates/repo/diff/conversation.tmpl b/templates/repo/diff/conversation.tmpl
index 8d4064967e..ce344794ea 100644
--- a/templates/repo/diff/conversation.tmpl
+++ b/templates/repo/diff/conversation.tmpl
@@ -1,14 +1,25 @@
 {{$resolved := (index .comments 0).IsResolved}}
+{{$invalid := (index .comments 0).Invalidated}}
 {{$resolveDoer := (index .comments 0).ResolveDoer}}
 {{$isNotPending := (not (eq (index .comments 0).Review.Type 0))}}
+{{$referenceUrl := printf "%s#%s" $.Issue.Link (index .comments 0).HashTag}}
 <div class="conversation-holder" data-path="{{(index .comments 0).TreePath}}" data-side="{{if lt (index .comments 0).Line 0}}left{{else}}right{{end}}" data-idx="{{(index .comments 0).UnsignedLine}}">
 	{{if $resolved}}
 		<div class="ui attached header resolved-placeholder gt-df gt-ac gt-sb">
-			<div class="ui grey text">
+			<div class="ui grey text gt-df gt-ac gt-fw gt-gap-2">
 				{{svg "octicon-check" 16 "icon gt-mr-2"}}
 				<b>{{$resolveDoer.Name}}</b> {{$.locale.Tr "repo.issues.review.resolved_by"}}
+				{{if $invalid}}
+					<!--
+					We only handle the case $resolved=true and $invalid=true in this template because if the comment is not resolved it has the outdated label in the comments area (not the header above).
+					The case $resolved=false and $invalid=true is handled in repo/diff/comments.tmpl
+					-->
+					<a href="{{AppSubUrl}}{{$referenceUrl}}" class="ui label basic small gt-ml-3" data-tooltip-content="{{$.locale.Tr "repo.issues.review.outdated_description"}}">
+						{{$.locale.Tr "repo.issues.review.outdated"}}
+					</a>
+				{{end}}
 			</div>
-			<div>
+			<div class="gt-df gt-ac gt-gap-3">
 				<button id="show-outdated-{{(index .comments 0).ID}}" data-comment="{{(index .comments 0).ID}}" class="ui tiny labeled button show-outdated gt-df gt-ac">
 					{{svg "octicon-unfold" 16 "gt-mr-3"}}
 					{{$.locale.Tr "repo.issues.review.show_resolved"}}
diff --git a/templates/repo/diff/options_dropdown.tmpl b/templates/repo/diff/options_dropdown.tmpl
index faf378b388..172e674770 100644
--- a/templates/repo/diff/options_dropdown.tmpl
+++ b/templates/repo/diff/options_dropdown.tmpl
@@ -14,5 +14,20 @@
 		{{end}}
 		<a id="expand-files-btn" class="item">{{.locale.Tr "repo.pulls.expand_files"}}</a>
 		<a id="collapse-files-btn"class="item">{{.locale.Tr "repo.pulls.collapse_files"}}</a>
+		{{if .Issue.Index}}
+			{{if .ShowOutdatedComments}}
+				<a class="item" href="?style={{if $.IsSplitStyle}}split{{else}}unified{{end}}&whitespace={{$.WhitespaceBehavior}}&show-outdated=false">
+					<label class="gt-pointer-events-none">
+						{{.locale.Tr "repo.issues.review.option.hide_outdated_comments"}}
+					</label>
+				</a>
+			{{else}}
+				<a class="item" href="?style={{if $.IsSplitStyle}}split{{else}}unified{{end}}&whitespace={{$.WhitespaceBehavior}}&show-outdated=true">
+					<label class="gt-pointer-events-none">
+						{{.locale.Tr "repo.issues.review.option.show_outdated_comments"}}
+					</label>
+				</a>
+			{{end}}
+		{{end}}
 	</div>
 </div>
diff --git a/templates/repo/diff/whitespace_dropdown.tmpl b/templates/repo/diff/whitespace_dropdown.tmpl
index 5a5b8c3dbd..a1830cb288 100644
--- a/templates/repo/diff/whitespace_dropdown.tmpl
+++ b/templates/repo/diff/whitespace_dropdown.tmpl
@@ -1,25 +1,25 @@
 <div class="ui dropdown tiny basic button" data-tooltip-content="{{.locale.Tr "repo.diff.whitespace_button"}}">
 	{{svg "gitea-whitespace"}}
 	<div class="menu">
-		<a class="item" href="?style={{if .IsSplitStyle}}split{{else}}unified{{end}}&whitespace=show-all">
+		<a class="item" href="?style={{if .IsSplitStyle}}split{{else}}unified{{end}}&whitespace=show-all&show-outdated={{$.ShowOutdatedComments}}">
 			<label class="gt-pointer-events-none">
 				<input class="gt-mr-3 gt-pointer-events-none" type="radio"{{if eq .WhitespaceBehavior "show-all"}} checked{{end}}>
 				{{.locale.Tr "repo.diff.whitespace_show_everything"}}
 			</label>
 		</a>
-		<a class="item" href="?style={{if .IsSplitStyle}}split{{else}}unified{{end}}&whitespace=ignore-all">
+		<a class="item" href="?style={{if .IsSplitStyle}}split{{else}}unified{{end}}&whitespace=ignore-all&show-outdated={{$.ShowOutdatedComments}}">
 			<label class="gt-pointer-events-none">
 				<input class="gt-mr-3 gt-pointer-events-none" type="radio"{{if eq .WhitespaceBehavior "ignore-all"}} checked{{end}}>
 				{{.locale.Tr "repo.diff.whitespace_ignore_all_whitespace"}}
 			</label>
 		</a>
-		<a class="item" href="?style={{if .IsSplitStyle}}split{{else}}unified{{end}}&whitespace=ignore-change">
+		<a class="item" href="?style={{if .IsSplitStyle}}split{{else}}unified{{end}}&whitespace=ignore-change&show-outdated={{$.ShowOutdatedComments}}">
 			<label class="gt-pointer-events-none">
 				<input class="gt-mr-3 gt-pointer-events-none" type="radio"{{if eq .WhitespaceBehavior "ignore-change"}} checked{{end}}>
 				{{.locale.Tr "repo.diff.whitespace_ignore_amount_changes"}}
 			</label>
 		</a>
-		<a class="item" href="?style={{if .IsSplitStyle}}split{{else}}unified{{end}}&whitespace=ignore-eol">
+		<a class="item" href="?style={{if .IsSplitStyle}}split{{else}}unified{{end}}&whitespace=ignore-eol&show-outdated={{$.ShowOutdatedComments}}">
 			<label class="gt-pointer-events-none">
 				<input class="gt-mr-3 gt-pointer-events-none" type="radio"{{if eq .WhitespaceBehavior "ignore-eol"}} checked{{end}}>
 				{{.locale.Tr "repo.diff.whitespace_ignore_at_eol"}}
@@ -27,4 +27,4 @@
 		</a>
 	</div>
 </div>
-<a class="ui tiny basic button" href="?style={{if .IsSplitStyle}}unified{{else}}split{{end}}&whitespace={{$.WhitespaceBehavior}}" data-tooltip-content="{{if .IsSplitStyle}}{{.locale.Tr "repo.diff.show_unified_view"}}{{else}}{{.locale.Tr "repo.diff.show_split_view"}}{{end}}">{{if .IsSplitStyle}}{{svg "gitea-join"}}{{else}}{{svg "gitea-split"}}{{end}}</a>
+<a class="ui tiny basic button" href="?style={{if .IsSplitStyle}}unified{{else}}split{{end}}&whitespace={{$.WhitespaceBehavior}}&show-outdated={{$.ShowOutdatedComments}}" data-tooltip-content="{{if .IsSplitStyle}}{{.locale.Tr "repo.diff.show_unified_view"}}{{else}}{{.locale.Tr "repo.diff.show_split_view"}}{{end}}">{{if .IsSplitStyle}}{{svg "gitea-join"}}{{else}}{{svg "gitea-split"}}{{end}}</a>