Fix issue content history problems, improve UI (#17404)

* Improve: make diff result better, make the HTML element fit the full height in the content history diff dialog
* Bug fix: when edit the main issue, the poster is wrongly set to the issue poster

models/issue.go

@@ -804,7 +804,7 @@ func (issue *Issue) ChangeContent(doer *User, content string) (err error) {
 		return fmt.Errorf("UpdateIssueCols: %v", err)
 	}
 
-	if err = issues.SaveIssueContentHistory(db.GetEngine(ctx), issue.PosterID, issue.ID, 0,
+	if err = issues.SaveIssueContentHistory(db.GetEngine(ctx), doer.ID, issue.ID, 0,
 		timeutil.TimeStampNow(), issue.Content, false); err != nil {
 		return fmt.Errorf("SaveIssueContentHistory: %v", err)
 	}
@@ -979,7 +979,7 @@ func newIssue(e db.Engine, doer *User, opts NewIssueOptions) (err error) {
 		return err
 	}
 
-	if err = issues.SaveIssueContentHistory(e, opts.Issue.PosterID, opts.Issue.ID, 0,
+	if err = issues.SaveIssueContentHistory(e, doer.ID, opts.Issue.ID, 0,
 		timeutil.TimeStampNow(), opts.Issue.Content, true); err != nil {
 		return err
 	}

models/issue_test.go

@@ -357,6 +357,7 @@ func testInsertIssue(t *testing.T, title, content string, expectIndex int64) *Is
 		issue := Issue{
 			RepoID:   repo.ID,
 			PosterID: user.ID,
+			Poster:   user,
 			Title:    title,
 			Content:  content,
 		}

routers/web/repo/issue_content_history.go

@@ -88,12 +88,13 @@ func canSoftDeleteContentHistory(ctx *context.Context, issue *models.Issue, comm
 	if ctx.Repo.IsOwner() {
 		canSoftDelete = true
 	} else if ctx.Repo.CanWrite(models.UnitTypeIssues) {
-		canSoftDelete = ctx.User.ID == history.PosterID
 		if comment == nil {
-			canSoftDelete = canSoftDelete && (ctx.User.ID == issue.PosterID)
+			// the issue poster or the history poster can soft-delete
+			canSoftDelete = ctx.User.ID == issue.PosterID || ctx.User.ID == history.PosterID
 			canSoftDelete = canSoftDelete && (history.IssueID == issue.ID)
 		} else {
-			canSoftDelete = canSoftDelete && (ctx.User.ID == comment.PosterID)
+			// the comment poster or the history poster can soft-delete
+			canSoftDelete = ctx.User.ID == comment.PosterID || ctx.User.ID == history.PosterID
 			canSoftDelete = canSoftDelete && (history.IssueID == issue.ID)
 			canSoftDelete = canSoftDelete && (history.CommentID == comment.ID)
 		}
@@ -137,7 +138,8 @@ func GetContentHistoryDetail(ctx *context.Context) {
 
 	// compare the current history revision with the previous one
 	dmp := diffmatchpatch.New()
-	diff := dmp.DiffMain(prevHistoryContentText, history.ContentText, true)
+	// `checklines=false` makes better diff result
+	diff := dmp.DiffMain(prevHistoryContentText, history.ContentText, false)
 	diff = dmp.DiffCleanupEfficiency(diff)
 
 	// use chroma to render the diff html

web_src/js/features/issue-content-history.js

@@ -12,7 +12,7 @@ function showContentHistoryDetail(issueBaseUrl, commentId, historyId, itemTitleH
   if ($dialog.length) return;
 
   $dialog = $(`
-<div class="ui modal content-history-detail-dialog" style="min-height: 50%;">
+<div class="ui modal content-history-detail-dialog">
   <i class="close icon inside"></i>
   <div class="header">
     ${itemTitleHtml}
@@ -24,7 +24,7 @@ function showContentHistoryDetail(issueBaseUrl, commentId, historyId, itemTitleH
     </div>
   </div>
   <!-- ".modal .content" style was polluted in "_base.less": "&.modal > .content"  -->
-  <div class="scrolling content" style="text-align: left;">
+  <div class="scrolling content" style="text-align: left; min-height: 30vh;">
       <div class="ui loader active"></div>
   </div>
 </div>`);