perf: Various performance regression fixes (#38078)

Fixes five N+1 / O(n) query patterns found across common user paths.
Each uses a bulk query that already existed elsewhere in the codebase.

| Location | Problem | Introduced in |
| -------------------------------- |
-------------------------------------------------------------------------------------------------------------------------------
| ------------- |
| `IssueList.LoadIsRead` | `.In("issue_id")` missing its arg — xorm
generates `WHERE 0=1`, so `IsRead` is **never** set; every issue always
appears unread | #29515 |
| `ParseCommitsWithStatus` | `GetLatestCommitStatus` called once per
commit (O(n) queries on commit list / PR commits tab) | #33605 |
| `getReleaseInfos` (release list) | `GetLatestCommitStatus` called once
per release for CI badges | #29149 |
| User milestone dashboard | O(n×m) nested loop matching milestones to
repos | #26300 |
| `findCodeComments` (PR diff) | `LoadResolveDoer` + `LoadReactions`
called per inline comment — up to ~150 queries on a PR with 50 comments
| #20821 |

---------

Co-authored-by: Lauris B <lauris@nix.lv>

models/issues/comment_code.go

@@ -79,6 +79,14 @@ func findCodeComments(ctx context.Context, opts FindCommentsOptions, issue *Issu
 		return nil, err
 	}
 
+	if err := comments.loadResolveDoers(ctx); err != nil {
+		return nil, err
+	}
+
+	if err := comments.loadReactions(ctx, issue.Repo); err != nil {
+		return nil, err
+	}
+
 	// Find all reviews by ReviewID
 	reviews := make(map[int64]*Review)
 	ids := make([]int64, 0, len(comments))
@@ -107,14 +115,6 @@ func findCodeComments(ctx context.Context, opts FindCommentsOptions, issue *Issu
 		comments[n] = comment
 		n++
 
-		if err := comment.LoadResolveDoer(ctx); err != nil {
-			return nil, err
-		}
-
-		if err := comment.LoadReactions(ctx, issue.Repo); err != nil {
-			return nil, err
-		}
-
 		var err error
 		rctx := renderhelper.NewRenderContextRepoComment(ctx, issue.Repo, renderhelper.RepoCommentOptions{
 			FootnoteContextID: strconv.FormatInt(comment.ID, 10),

models/issues/comment_list.go

@@ -11,6 +11,7 @@ import (
 	user_model "gitea.dev/models/user"
 	"gitea.dev/modules/container"
 	"gitea.dev/modules/log"
+	"gitea.dev/modules/setting"
 )
 
 // CommentList defines a list of comments
@@ -444,6 +445,73 @@ func (comments CommentList) loadReviews(ctx context.Context) error {
 	return nil
 }
 
+// loadResolveDoers bulk-loads the resolve doer for all code comments that have one.
+func (comments CommentList) loadResolveDoers(ctx context.Context) error {
+	resolveDoerIDs := container.FilterSlice(comments, func(c *Comment) (int64, bool) {
+		return c.ResolveDoerID, c.ResolveDoerID != 0 && c.Type == CommentTypeCode
+	})
+	if len(resolveDoerIDs) == 0 {
+		return nil
+	}
+
+	userMaps, err := user_model.GetUsersMapByIDs(ctx, resolveDoerIDs)
+	if err != nil {
+		return err
+	}
+
+	for _, comment := range comments {
+		if comment.ResolveDoerID == 0 || comment.Type != CommentTypeCode {
+			continue
+		}
+		if u, ok := userMaps[comment.ResolveDoerID]; ok {
+			comment.ResolveDoer = u
+		} else {
+			comment.ResolveDoer = user_model.NewGhostUser()
+		}
+	}
+	return nil
+}
+
+// loadReactions bulk-loads reactions for all comments in the list.
+func (comments CommentList) loadReactions(ctx context.Context, repo *repo_model.Repository) error {
+	if len(comments) == 0 {
+		return nil
+	}
+
+	commentIDs := container.FilterSlice(comments, func(c *Comment) (int64, bool) {
+		return c.ID, c.Reactions == nil
+	})
+	if len(commentIDs) == 0 {
+		return nil
+	}
+
+	var allReactions ReactionList
+	if err := db.GetEngine(ctx).
+		Where("`comment_id` > 0").
+		In("comment_id", commentIDs).
+		In("`type`", setting.UI.Reactions).
+		Asc("issue_id", "comment_id", "created_unix", "id").
+		Find(&allReactions); err != nil {
+		return err
+	}
+
+	if _, err := allReactions.LoadUsers(ctx, repo); err != nil {
+		return err
+	}
+
+	reactByComment := make(map[int64]ReactionList, len(commentIDs))
+	for _, r := range allReactions {
+		reactByComment[r.CommentID] = append(reactByComment[r.CommentID], r)
+	}
+
+	for _, comment := range comments {
+		if comment.Reactions == nil {
+			comment.Reactions = reactByComment[comment.ID]
+		}
+	}
+	return nil
+}
+
 // LoadAttributes loads attributes of the comments, except for attachments and
 // comments
 func (comments CommentList) LoadAttributes(ctx context.Context) (err error) {

models/issues/issue_list.go

@@ -591,9 +591,12 @@ func (issues IssueList) GetApprovalCounts(ctx context.Context) (map[int64][]*Rev
 
 func (issues IssueList) LoadIsRead(ctx context.Context, userID int64) error {
 	issueIDs := issues.getIssueIDs()
+	if len(issueIDs) == 0 {
+		return nil
+	}
 	issueUsers := make([]*IssueUser, 0, len(issueIDs))
 	if err := db.GetEngine(ctx).Where("uid =?", userID).
-		In("issue_id").
+		In("issue_id", issueIDs).
 		Find(&issueUsers); err != nil {
 		return err
 	}

models/issues/issue_list_test.go

@@ -11,6 +11,7 @@ import (
 	"gitea.dev/modules/setting"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestIssueList_LoadRepositories(t *testing.T) {
@@ -30,6 +31,22 @@ func TestIssueList_LoadRepositories(t *testing.T) {
 	}
 }
 
+func TestIssueList_LoadIsRead(t *testing.T) {
+	// Regression: In("issue_id") was missing the issueIDs argument, causing
+	// xorm to generate "0=1" and never mark any issue as read.
+	require.NoError(t, unittest.PrepareTestDatabase())
+
+	issue1 := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{ID: 1})
+	issue2 := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{ID: 2})
+
+	// Fixture: uid=1 has is_read=true on issue 1 only.
+	issueList := issues_model.IssueList{issue1, issue2}
+	require.NoError(t, issueList.LoadIsRead(t.Context(), 1))
+
+	assert.True(t, issue1.IsRead, "issue 1 should be marked read for user 1")
+	assert.False(t, issue2.IsRead, "issue 2 should not be marked read for user 1")
+}
+
 func TestIssueList_LoadAttributes(t *testing.T) {
 	assert.NoError(t, unittest.PrepareTestDatabase())
 	setting.Service.EnableTimetracking = true