diff --git a/models/activities/action.go b/models/activities/action.go
index 9b4ffd7725..c83dba9d46 100644
--- a/models/activities/action.go
+++ b/models/activities/action.go
@@ -171,7 +171,10 @@ func (a *Action) TableIndices() []*schemas.Index {
 	cudIndex := schemas.NewIndex("c_u_d", schemas.IndexType)
 	cudIndex.AddColumn("created_unix", "user_id", "is_deleted")
 
-	indices := []*schemas.Index{actUserIndex, repoIndex, cudIndex}
+	cuIndex := schemas.NewIndex("c_u", schemas.IndexType)
+	cuIndex.AddColumn("user_id", "is_deleted")
+
+	indices := []*schemas.Index{actUserIndex, repoIndex, cudIndex, cuIndex}
 
 	return indices
 }
diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 5b2befd0fd..095b18f9fa 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -365,7 +365,8 @@ func prepareMigrationTasks() []*migration {
 		newMigration(305, "Add Repository Licenses", v1_23.AddRepositoryLicenses),
 		newMigration(306, "Add BlockAdminMergeOverride to ProtectedBranch", v1_23.AddBlockAdminMergeOverrideBranchProtection),
 		newMigration(307, "Fix milestone deadline_unix when there is no due date", v1_23.FixMilestoneNoDueDate),
-		newMigration(308, "Add table issue_dev_link", v1_23.CreateTableIssueDevLink),
+		newMigration(308, "Add index(user_id, is_deleted) for action table", v1_23.AddNewIndexForUserDashboard),
+		newMigration(309, "Add table issue_dev_link", v1_23.CreateTableIssueDevLink),
 	}
 	return preparedMigrations
 }
diff --git a/models/migrations/v1_23/v308.go b/models/migrations/v1_23/v308.go
index c017890b50..1e8a9b0af2 100644
--- a/models/migrations/v1_23/v308.go
+++ b/models/migrations/v1_23/v308.go
@@ -7,16 +7,46 @@ import (
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"xorm.io/xorm"
+	"xorm.io/xorm/schemas"
 )
 
-func CreateTableIssueDevLink(x *xorm.Engine) error {
-	type IssueDevLink struct {
-		ID           int64 `xorm:"pk autoincr"`
-		IssueID      int64 `xorm:"INDEX"`
-		LinkType     int
-		LinkedRepoID int64              `xorm:"INDEX"` // it can link to self repo or other repo
-		LinkIndex    string             // branch name, pull request number or commit sha
-		CreatedUnix  timeutil.TimeStamp `xorm:"INDEX created"`
-	}
-	return x.Sync(new(IssueDevLink))
+type improveActionTableIndicesAction struct {
+	ID          int64 `xorm:"pk autoincr"`
+	UserID      int64 `xorm:"INDEX"` // Receiver user id.
+	OpType      int
+	ActUserID   int64 // Action user id.
+	RepoID      int64
+	CommentID   int64 `xorm:"INDEX"`
+	IsDeleted   bool  `xorm:"NOT NULL DEFAULT false"`
+	RefName     string
+	IsPrivate   bool               `xorm:"NOT NULL DEFAULT false"`
+	Content     string             `xorm:"TEXT"`
+	CreatedUnix timeutil.TimeStamp `xorm:"created"`
+}
+
+// TableName sets the name of this table
+func (*improveActionTableIndicesAction) TableName() string {
+	return "action"
+}
+
+func (a *improveActionTableIndicesAction) TableIndices() []*schemas.Index {
+	repoIndex := schemas.NewIndex("r_u_d", schemas.IndexType)
+	repoIndex.AddColumn("repo_id", "user_id", "is_deleted")
+
+	actUserIndex := schemas.NewIndex("au_r_c_u_d", schemas.IndexType)
+	actUserIndex.AddColumn("act_user_id", "repo_id", "created_unix", "user_id", "is_deleted")
+
+	cudIndex := schemas.NewIndex("c_u_d", schemas.IndexType)
+	cudIndex.AddColumn("created_unix", "user_id", "is_deleted")
+
+	cuIndex := schemas.NewIndex("c_u", schemas.IndexType)
+	cuIndex.AddColumn("user_id", "is_deleted")
+
+	indices := []*schemas.Index{actUserIndex, repoIndex, cudIndex, cuIndex}
+
+	return indices
+}
+
+func AddNewIndexForUserDashboard(x *xorm.Engine) error {
+	return x.Sync(new(improveActionTableIndicesAction))
 }
diff --git a/models/migrations/v1_23/v309.go b/models/migrations/v1_23/v309.go
new file mode 100644
index 0000000000..c017890b50
--- /dev/null
+++ b/models/migrations/v1_23/v309.go
@@ -0,0 +1,22 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_23 //nolint
+
+import (
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"xorm.io/xorm"
+)
+
+func CreateTableIssueDevLink(x *xorm.Engine) error {
+	type IssueDevLink struct {
+		ID           int64 `xorm:"pk autoincr"`
+		IssueID      int64 `xorm:"INDEX"`
+		LinkType     int
+		LinkedRepoID int64              `xorm:"INDEX"` // it can link to self repo or other repo
+		LinkIndex    string             // branch name, pull request number or commit sha
+		CreatedUnix  timeutil.TimeStamp `xorm:"INDEX created"`
+	}
+	return x.Sync(new(IssueDevLink))
+}
diff --git a/modules/indexer/code/bleve/bleve.go b/modules/indexer/code/bleve/bleve.go
index 90e5e62bcb..772317fa59 100644
--- a/modules/indexer/code/bleve/bleve.go
+++ b/modules/indexer/code/bleve/bleve.go
@@ -31,6 +31,7 @@ import (
 	"github.com/blevesearch/bleve/v2/analysis/token/camelcase"
 	"github.com/blevesearch/bleve/v2/analysis/token/lowercase"
 	"github.com/blevesearch/bleve/v2/analysis/token/unicodenorm"
+	"github.com/blevesearch/bleve/v2/analysis/tokenizer/letter"
 	"github.com/blevesearch/bleve/v2/analysis/tokenizer/unicode"
 	"github.com/blevesearch/bleve/v2/mapping"
 	"github.com/blevesearch/bleve/v2/search/query"
@@ -69,7 +70,7 @@ const (
 	filenameIndexerAnalyzer  = "filenameIndexerAnalyzer"
 	filenameIndexerTokenizer = "filenameIndexerTokenizer"
 	repoIndexerDocType       = "repoIndexerDocType"
-	repoIndexerLatestVersion = 7
+	repoIndexerLatestVersion = 8
 )
 
 // generateBleveIndexMapping generates a bleve index mapping for the repo indexer
@@ -105,7 +106,7 @@ func generateBleveIndexMapping() (mapping.IndexMapping, error) {
 	} else if err := mapping.AddCustomAnalyzer(repoIndexerAnalyzer, map[string]any{
 		"type":          analyzer_custom.Name,
 		"char_filters":  []string{},
-		"tokenizer":     unicode.Name,
+		"tokenizer":     letter.Name,
 		"token_filters": []string{unicodeNormalizeName, camelcase.Name, lowercase.Name},
 	}); err != nil {
 		return nil, err
diff --git a/modules/indexer/code/elasticsearch/elasticsearch.go b/modules/indexer/code/elasticsearch/elasticsearch.go
index 669a1bafcc..1c4dd39eff 100644
--- a/modules/indexer/code/elasticsearch/elasticsearch.go
+++ b/modules/indexer/code/elasticsearch/elasticsearch.go
@@ -30,7 +30,7 @@ import (
 )
 
 const (
-	esRepoIndexerLatestVersion = 2
+	esRepoIndexerLatestVersion = 3
 	// multi-match-types, currently only 2 types are used
 	// Reference: https://www.elastic.co/guide/en/elasticsearch/reference/7.0/query-dsl-multi-match-query.html#multi-match-types
 	esMultiMatchTypeBestFields   = "best_fields"
@@ -60,6 +60,10 @@ const (
 		"settings": {
     		"analysis": {
       			"analyzer": {
+					"content_analyzer": {
+						"tokenizer": "content_tokenizer",
+						"filter" : ["lowercase"]
+					},
         			"filename_path_analyzer": {
           				"tokenizer": "path_tokenizer"
         			},
@@ -68,6 +72,10 @@ const (
         			}
       			},
 				"tokenizer": {
+					"content_tokenizer": {
+						"type": "simple_pattern_split",
+						"pattern": "[^a-zA-Z0-9]"
+					},
 					"path_tokenizer": {
 						"type": "path_hierarchy",
 						"delimiter": "/"
@@ -104,7 +112,8 @@ const (
 				"content": {
 					"type": "text",
 					"term_vector": "with_positions_offsets",
-					"index": true
+					"index": true,
+					"analyzer": "content_analyzer"
 				},
 				"commit_id": {
 					"type": "keyword",
diff --git a/modules/indexer/code/indexer_test.go b/modules/indexer/code/indexer_test.go
index 5b33528dcd..020ccc72f8 100644
--- a/modules/indexer/code/indexer_test.go
+++ b/modules/indexer/code/indexer_test.go
@@ -181,6 +181,55 @@ func testIndexer(name string, t *testing.T, indexer internal.Indexer) {
 					},
 				},
 			},
+			// Search for matches on the contents of files regardless of case.
+			{
+				RepoIDs: nil,
+				Keyword: "dESCRIPTION",
+				Langs:   1,
+				Results: []codeSearchResult{
+					{
+						Filename: "README.md",
+						Content:  "# repo1\n\nDescription for repo1",
+					},
+				},
+			},
+			// Search for an exact match on the filename within the repo '62' (case insenstive).
+			// This scenario yields a single result (the file avocado.md on the repo '62')
+			{
+				RepoIDs: []int64{62},
+				Keyword: "AVOCADO.MD",
+				Langs:   1,
+				Results: []codeSearchResult{
+					{
+						Filename: "avocado.md",
+						Content:  "# repo1\n\npineaple pie of cucumber juice",
+					},
+				},
+			},
+			// Search for matches on the contents of files when the criteria is a expression.
+			{
+				RepoIDs: []int64{62},
+				Keyword: "console.log",
+				Langs:   1,
+				Results: []codeSearchResult{
+					{
+						Filename: "example-file.js",
+						Content:  "console.log(\"Hello, World!\")",
+					},
+				},
+			},
+			// Search for matches on the contents of files when the criteria is part of a expression.
+			{
+				RepoIDs: []int64{62},
+				Keyword: "log",
+				Langs:   1,
+				Results: []codeSearchResult{
+					{
+						Filename: "example-file.js",
+						Content:  "console.log(\"Hello, World!\")",
+					},
+				},
+			},
 		}
 
 		for _, kw := range keywords {
diff --git a/modules/indexer/internal/bleve/util.go b/modules/indexer/internal/bleve/util.go
index b426b39bc2..a0c3dc4ad4 100644
--- a/modules/indexer/internal/bleve/util.go
+++ b/modules/indexer/internal/bleve/util.go
@@ -6,12 +6,13 @@ package bleve
 import (
 	"errors"
 	"os"
+	"unicode"
 
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/blevesearch/bleve/v2"
-	"github.com/blevesearch/bleve/v2/analysis/tokenizer/unicode"
+	unicode_tokenizer "github.com/blevesearch/bleve/v2/analysis/tokenizer/unicode"
 	"github.com/blevesearch/bleve/v2/index/upsidedown"
 	"github.com/ethantkoenig/rupture"
 )
@@ -57,7 +58,7 @@ func openIndexer(path string, latestVersion int) (bleve.Index, int, error) {
 // may be different on two string and they still be considered equivalent.
 // Given a phrasse, its shortest word determines its fuzziness. If a phrase uses CJK (eg: `갃갃갃` `啊啊啊`), the fuzziness is zero.
 func GuessFuzzinessByKeyword(s string) int {
-	tokenizer := unicode.NewUnicodeTokenizer()
+	tokenizer := unicode_tokenizer.NewUnicodeTokenizer()
 	tokens := tokenizer.Tokenize([]byte(s))
 
 	if len(tokens) > 0 {
@@ -77,8 +78,10 @@ func guessFuzzinessByKeyword(s string) int {
 	// according to https://github.com/blevesearch/bleve/issues/1563, the supported max fuzziness is 2
 	// magic number 4 was chosen to determine the levenshtein distance per each character of a keyword
 	// BUT, when using CJK (eg: `갃갃갃` `啊啊啊`), it mismatches a lot.
+	// Likewise, queries whose terms contains characters that are *not* letters should not use fuzziness
+
 	for _, r := range s {
-		if r >= 128 {
+		if r >= 128 || !unicode.IsLetter(r) {
 			return 0
 		}
 	}
diff --git a/modules/indexer/internal/bleve/util_test.go b/modules/indexer/internal/bleve/util_test.go
index ae0b12c08d..8f7844464e 100644
--- a/modules/indexer/internal/bleve/util_test.go
+++ b/modules/indexer/internal/bleve/util_test.go
@@ -35,6 +35,14 @@ func TestBleveGuessFuzzinessByKeyword(t *testing.T) {
 			Input:     "갃갃갃",
 			Fuzziness: 0,
 		},
+		{
+			Input:     "repo1",
+			Fuzziness: 0,
+		},
+		{
+			Input:     "avocado.md",
+			Fuzziness: 0,
+		},
 	}
 
 	for _, scenario := range scenarios {
diff --git a/routers/api/v1/repo/issue_attachment.go b/routers/api/v1/repo/issue_attachment.go
index 27c7af2282..d0bcadde37 100644
--- a/routers/api/v1/repo/issue_attachment.go
+++ b/routers/api/v1/repo/issue_attachment.go
@@ -12,7 +12,7 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/web"
-	"code.gitea.io/gitea/services/attachment"
+	attachment_service "code.gitea.io/gitea/services/attachment"
 	"code.gitea.io/gitea/services/context"
 	"code.gitea.io/gitea/services/context/upload"
 	"code.gitea.io/gitea/services/convert"
@@ -181,7 +181,7 @@ func CreateIssueAttachment(ctx *context.APIContext) {
 		filename = query
 	}
 
-	attachment, err := attachment.UploadAttachment(ctx, file, setting.Attachment.AllowedTypes, header.Size, &repo_model.Attachment{
+	attachment, err := attachment_service.UploadAttachment(ctx, file, setting.Attachment.AllowedTypes, header.Size, &repo_model.Attachment{
 		Name:       filename,
 		UploaderID: ctx.Doer.ID,
 		RepoID:     ctx.Repo.Repository.ID,
@@ -247,6 +247,8 @@ func EditIssueAttachment(ctx *context.APIContext) {
 	//     "$ref": "#/responses/Attachment"
 	//   "404":
 	//     "$ref": "#/responses/error"
+	//   "422":
+	//     "$ref": "#/responses/validationError"
 	//   "423":
 	//     "$ref": "#/responses/repoArchivedError"
 
@@ -261,8 +263,13 @@ func EditIssueAttachment(ctx *context.APIContext) {
 		attachment.Name = form.Name
 	}
 
-	if err := repo_model.UpdateAttachment(ctx, attachment); err != nil {
+	if err := attachment_service.UpdateAttachment(ctx, setting.Attachment.AllowedTypes, attachment); err != nil {
+		if upload.IsErrFileTypeForbidden(err) {
+			ctx.Error(http.StatusUnprocessableEntity, "", err)
+			return
+		}
 		ctx.Error(http.StatusInternalServerError, "UpdateAttachment", err)
+		return
 	}
 
 	ctx.JSON(http.StatusCreated, convert.ToAPIAttachment(ctx.Repo.Repository, attachment))
diff --git a/routers/api/v1/repo/issue_comment_attachment.go b/routers/api/v1/repo/issue_comment_attachment.go
index 0863ebd182..a556a803e5 100644
--- a/routers/api/v1/repo/issue_comment_attachment.go
+++ b/routers/api/v1/repo/issue_comment_attachment.go
@@ -14,7 +14,7 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/web"
-	"code.gitea.io/gitea/services/attachment"
+	attachment_service "code.gitea.io/gitea/services/attachment"
 	"code.gitea.io/gitea/services/context"
 	"code.gitea.io/gitea/services/context/upload"
 	"code.gitea.io/gitea/services/convert"
@@ -189,7 +189,7 @@ func CreateIssueCommentAttachment(ctx *context.APIContext) {
 		filename = query
 	}
 
-	attachment, err := attachment.UploadAttachment(ctx, file, setting.Attachment.AllowedTypes, header.Size, &repo_model.Attachment{
+	attachment, err := attachment_service.UploadAttachment(ctx, file, setting.Attachment.AllowedTypes, header.Size, &repo_model.Attachment{
 		Name:       filename,
 		UploaderID: ctx.Doer.ID,
 		RepoID:     ctx.Repo.Repository.ID,
@@ -263,6 +263,8 @@ func EditIssueCommentAttachment(ctx *context.APIContext) {
 	//     "$ref": "#/responses/Attachment"
 	//   "404":
 	//     "$ref": "#/responses/error"
+	//   "422":
+	//     "$ref": "#/responses/validationError"
 	//   "423":
 	//     "$ref": "#/responses/repoArchivedError"
 	attach := getIssueCommentAttachmentSafeWrite(ctx)
@@ -275,8 +277,13 @@ func EditIssueCommentAttachment(ctx *context.APIContext) {
 		attach.Name = form.Name
 	}
 
-	if err := repo_model.UpdateAttachment(ctx, attach); err != nil {
+	if err := attachment_service.UpdateAttachment(ctx, setting.Attachment.AllowedTypes, attach); err != nil {
+		if upload.IsErrFileTypeForbidden(err) {
+			ctx.Error(http.StatusUnprocessableEntity, "", err)
+			return
+		}
 		ctx.Error(http.StatusInternalServerError, "UpdateAttachment", attach)
+		return
 	}
 	ctx.JSON(http.StatusCreated, convert.ToAPIAttachment(ctx.Repo.Repository, attach))
 }
diff --git a/routers/api/v1/repo/release_attachment.go b/routers/api/v1/repo/release_attachment.go
index 4a2371e012..ed6cc8e1ea 100644
--- a/routers/api/v1/repo/release_attachment.go
+++ b/routers/api/v1/repo/release_attachment.go
@@ -13,7 +13,7 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/web"
-	"code.gitea.io/gitea/services/attachment"
+	attachment_service "code.gitea.io/gitea/services/attachment"
 	"code.gitea.io/gitea/services/context"
 	"code.gitea.io/gitea/services/context/upload"
 	"code.gitea.io/gitea/services/convert"
@@ -234,7 +234,7 @@ func CreateReleaseAttachment(ctx *context.APIContext) {
 	}
 
 	// Create a new attachment and save the file
-	attach, err := attachment.UploadAttachment(ctx, content, setting.Repository.Release.AllowedTypes, size, &repo_model.Attachment{
+	attach, err := attachment_service.UploadAttachment(ctx, content, setting.Repository.Release.AllowedTypes, size, &repo_model.Attachment{
 		Name:       filename,
 		UploaderID: ctx.Doer.ID,
 		RepoID:     ctx.Repo.Repository.ID,
@@ -291,6 +291,8 @@ func EditReleaseAttachment(ctx *context.APIContext) {
 	// responses:
 	//   "201":
 	//     "$ref": "#/responses/Attachment"
+	//   "422":
+	//     "$ref": "#/responses/validationError"
 	//   "404":
 	//     "$ref": "#/responses/notFound"
 
@@ -322,8 +324,13 @@ func EditReleaseAttachment(ctx *context.APIContext) {
 		attach.Name = form.Name
 	}
 
-	if err := repo_model.UpdateAttachment(ctx, attach); err != nil {
+	if err := attachment_service.UpdateAttachment(ctx, setting.Repository.Release.AllowedTypes, attach); err != nil {
+		if upload.IsErrFileTypeForbidden(err) {
+			ctx.Error(http.StatusUnprocessableEntity, "", err)
+			return
+		}
 		ctx.Error(http.StatusInternalServerError, "UpdateAttachment", attach)
+		return
 	}
 	ctx.JSON(http.StatusCreated, convert.ToAPIAttachment(ctx.Repo.Repository, attach))
 }
diff --git a/services/attachment/attachment.go b/services/attachment/attachment.go
index 0fd51e4fa5..ccb97c66c8 100644
--- a/services/attachment/attachment.go
+++ b/services/attachment/attachment.go
@@ -50,3 +50,12 @@ func UploadAttachment(ctx context.Context, file io.Reader, allowedTypes string,
 
 	return NewAttachment(ctx, attach, io.MultiReader(bytes.NewReader(buf), file), fileSize)
 }
+
+// UpdateAttachment updates an attachment, verifying that its name is among the allowed types.
+func UpdateAttachment(ctx context.Context, allowedTypes string, attach *repo_model.Attachment) error {
+	if err := upload.Verify(nil, attach.Name, allowedTypes); err != nil {
+		return err
+	}
+
+	return repo_model.UpdateAttachment(ctx, attach)
+}
diff --git a/services/context/upload/upload.go b/services/context/upload/upload.go
index 7123420e99..cefd13ebb6 100644
--- a/services/context/upload/upload.go
+++ b/services/context/upload/upload.go
@@ -28,12 +28,13 @@ func IsErrFileTypeForbidden(err error) bool {
 }
 
 func (err ErrFileTypeForbidden) Error() string {
-	return "This file extension or type is not allowed to be uploaded."
+	return "This file cannot be uploaded or modified due to a forbidden file extension or type."
 }
 
 var wildcardTypeRe = regexp.MustCompile(`^[a-z]+/\*$`)
 
-// Verify validates whether a file is allowed to be uploaded.
+// Verify validates whether a file is allowed to be uploaded. If buf is empty, it will just check if the file
+// has an allowed file extension.
 func Verify(buf []byte, fileName, allowedTypesStr string) error {
 	allowedTypesStr = strings.ReplaceAll(allowedTypesStr, "|", ",") // compat for old config format
 
@@ -56,21 +57,31 @@ func Verify(buf []byte, fileName, allowedTypesStr string) error {
 		return ErrFileTypeForbidden{Type: fullMimeType}
 	}
 	extension := strings.ToLower(path.Ext(fileName))
+	isBufEmpty := len(buf) <= 1
 
 	// https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/file#Unique_file_type_specifiers
 	for _, allowEntry := range allowedTypes {
 		if allowEntry == "*/*" {
 			return nil // everything allowed
-		} else if strings.HasPrefix(allowEntry, ".") && allowEntry == extension {
+		}
+		if strings.HasPrefix(allowEntry, ".") && allowEntry == extension {
 			return nil // extension is allowed
-		} else if mimeType == allowEntry {
+		}
+		if isBufEmpty {
+			continue // skip mime type checks if buffer is empty
+		}
+		if mimeType == allowEntry {
 			return nil // mime type is allowed
-		} else if wildcardTypeRe.MatchString(allowEntry) && strings.HasPrefix(mimeType, allowEntry[:len(allowEntry)-1]) {
+		}
+		if wildcardTypeRe.MatchString(allowEntry) && strings.HasPrefix(mimeType, allowEntry[:len(allowEntry)-1]) {
 			return nil // wildcard match, e.g. image/*
 		}
 	}
 
-	log.Info("Attachment with type %s blocked from upload", fullMimeType)
+	if !isBufEmpty {
+		log.Info("Attachment with type %s blocked from upload", fullMimeType)
+	}
+
 	return ErrFileTypeForbidden{Type: fullMimeType}
 }
 
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 92a8888f32..01b12460ac 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -7706,6 +7706,9 @@
           "404": {
             "$ref": "#/responses/error"
           },
+          "422": {
+            "$ref": "#/responses/validationError"
+          },
           "423": {
             "$ref": "#/responses/repoArchivedError"
           }
@@ -8328,6 +8331,9 @@
           "404": {
             "$ref": "#/responses/error"
           },
+          "422": {
+            "$ref": "#/responses/validationError"
+          },
           "423": {
             "$ref": "#/responses/repoArchivedError"
           }
@@ -13474,6 +13480,9 @@
           },
           "404": {
             "$ref": "#/responses/notFound"
+          },
+          "422": {
+            "$ref": "#/responses/validationError"
           }
         }
       }
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/description b/tests/gitea-repositories-meta/org42/search-by-path.git/description
index 382e2d7f10..ffc40a9c48 100644
--- a/tests/gitea-repositories-meta/org42/search-by-path.git/description
+++ b/tests/gitea-repositories-meta/org42/search-by-path.git/description
@@ -4,5 +4,6 @@ This repository will be used to test code search. The snippet below shows its di
 ├── avocado.md
 ├── cucumber.md
 ├── ham.md
-└── potato
-    └── ham.md
+├── potato
+|   └── ham.md
+└── example-file.js
\ No newline at end of file
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/info/refs b/tests/gitea-repositories-meta/org42/search-by-path.git/info/refs
index 6b948c96a8..4adf83dda3 100644
--- a/tests/gitea-repositories-meta/org42/search-by-path.git/info/refs
+++ b/tests/gitea-repositories-meta/org42/search-by-path.git/info/refs
@@ -3,7 +3,7 @@
 65f1bf27bc3bf70f64657658635e66094edbcb4d	refs/heads/develop
 65f1bf27bc3bf70f64657658635e66094edbcb4d	refs/heads/feature/1
 78fb907e3a3309eae4fe8fef030874cebbf1cd5e	refs/heads/home-md-img-check
-3731fe53b763859aaf83e703ee731f6b9447ff1e	refs/heads/master
+9f894b61946fd2f7b8b9d8e370e4d62f915522f5	refs/heads/master
 62fb502a7172d4453f0322a2cc85bddffa57f07a	refs/heads/pr-to-update
 4649299398e4d39a5c09eb4f534df6f1e1eb87cc	refs/heads/sub-home-md-img-check
 3fa2f829675543ecfc16b2891aebe8bf0608a8f4	refs/notes/commits
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/info/commit-graph b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/info/commit-graph
deleted file mode 100644
index b38715bb92..0000000000
Binary files a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/info/commit-graph and /dev/null differ
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/info/packs b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/info/packs
index b2af8c8378..9774923d2e 100644
--- a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/info/packs
+++ b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/info/packs
@@ -1,2 +1,2 @@
-P pack-393dc29256bc27cb2ec73898507df710be7a3cf5.pack
+P pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.pack
 
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.bitmap b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.bitmap
deleted file mode 100644
index 1fdef225e8..0000000000
Binary files a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.bitmap and /dev/null differ
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.idx b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.idx
deleted file mode 100644
index 0d930e7499..0000000000
Binary files a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.idx and /dev/null differ
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.rev b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.rev
deleted file mode 100644
index 869860ba61..0000000000
Binary files a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.rev and /dev/null differ
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.bitmap b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.bitmap
new file mode 100644
index 0000000000..39c02c2987
Binary files /dev/null and b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.bitmap differ
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.idx b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.idx
new file mode 100644
index 0000000000..38d0e6b722
Binary files /dev/null and b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.idx differ
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.pack b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.pack
similarity index 74%
rename from tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.pack
rename to tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.pack
index f1aac1e740..06c0a899f3 100644
Binary files a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-393dc29256bc27cb2ec73898507df710be7a3cf5.pack and b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.pack differ
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.rev b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.rev
new file mode 100644
index 0000000000..b06ecca825
Binary files /dev/null and b/tests/gitea-repositories-meta/org42/search-by-path.git/objects/pack/pack-a7bef76cf6e2b46bc816936ab69306fb10aea571.rev differ
diff --git a/tests/gitea-repositories-meta/org42/search-by-path.git/packed-refs b/tests/gitea-repositories-meta/org42/search-by-path.git/packed-refs
index 70e69af1e1..2334e3da48 100644
--- a/tests/gitea-repositories-meta/org42/search-by-path.git/packed-refs
+++ b/tests/gitea-repositories-meta/org42/search-by-path.git/packed-refs
@@ -4,7 +4,7 @@
 65f1bf27bc3bf70f64657658635e66094edbcb4d refs/heads/develop
 65f1bf27bc3bf70f64657658635e66094edbcb4d refs/heads/feature/1
 78fb907e3a3309eae4fe8fef030874cebbf1cd5e refs/heads/home-md-img-check
-3731fe53b763859aaf83e703ee731f6b9447ff1e refs/heads/master
+9f894b61946fd2f7b8b9d8e370e4d62f915522f5 refs/heads/master
 62fb502a7172d4453f0322a2cc85bddffa57f07a refs/heads/pr-to-update
 4649299398e4d39a5c09eb4f534df6f1e1eb87cc refs/heads/sub-home-md-img-check
 3fa2f829675543ecfc16b2891aebe8bf0608a8f4 refs/notes/commits
diff --git a/tests/integration/api_comment_attachment_test.go b/tests/integration/api_comment_attachment_test.go
index 0ec950d4c2..623467938a 100644
--- a/tests/integration/api_comment_attachment_test.go
+++ b/tests/integration/api_comment_attachment_test.go
@@ -151,7 +151,7 @@ func TestAPICreateCommentAttachmentWithUnallowedFile(t *testing.T) {
 func TestAPIEditCommentAttachment(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
-	const newAttachmentName = "newAttachmentName"
+	const newAttachmentName = "newAttachmentName.txt"
 
 	attachment := unittest.AssertExistsAndLoadBean(t, &repo_model.Attachment{ID: 6})
 	comment := unittest.AssertExistsAndLoadBean(t, &issues_model.Comment{ID: attachment.CommentID})
@@ -173,6 +173,27 @@ func TestAPIEditCommentAttachment(t *testing.T) {
 	unittest.AssertExistsAndLoadBean(t, &repo_model.Attachment{ID: apiAttachment.ID, CommentID: comment.ID, Name: apiAttachment.Name})
 }
 
+func TestAPIEditCommentAttachmentWithUnallowedFile(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	attachment := unittest.AssertExistsAndLoadBean(t, &repo_model.Attachment{ID: 6})
+	comment := unittest.AssertExistsAndLoadBean(t, &issues_model.Comment{ID: attachment.CommentID})
+	issue := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{ID: comment.IssueID})
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: issue.RepoID})
+	repoOwner := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
+	session := loginUser(t, repoOwner.Name)
+	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteIssue)
+
+	filename := "file.bad"
+	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/comments/%d/assets/%d",
+		repoOwner.Name, repo.Name, comment.ID, attachment.ID)
+	req := NewRequestWithValues(t, "PATCH", urlStr, map[string]string{
+		"name": filename,
+	}).AddTokenAuth(token)
+
+	session.MakeRequest(t, req, http.StatusUnprocessableEntity)
+}
+
 func TestAPIDeleteCommentAttachment(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
diff --git a/tests/integration/api_issue_attachment_test.go b/tests/integration/api_issue_attachment_test.go
index b4196ec6db..6806d27df2 100644
--- a/tests/integration/api_issue_attachment_test.go
+++ b/tests/integration/api_issue_attachment_test.go
@@ -126,7 +126,7 @@ func TestAPICreateIssueAttachmentWithUnallowedFile(t *testing.T) {
 func TestAPIEditIssueAttachment(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
-	const newAttachmentName = "newAttachmentName"
+	const newAttachmentName = "hello_world.txt"
 
 	attachment := unittest.AssertExistsAndLoadBean(t, &repo_model.Attachment{ID: 1})
 	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: attachment.RepoID})
@@ -147,6 +147,26 @@ func TestAPIEditIssueAttachment(t *testing.T) {
 	unittest.AssertExistsAndLoadBean(t, &repo_model.Attachment{ID: apiAttachment.ID, IssueID: issue.ID, Name: apiAttachment.Name})
 }
 
+func TestAPIEditIssueAttachmentWithUnallowedFile(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	attachment := unittest.AssertExistsAndLoadBean(t, &repo_model.Attachment{ID: 1})
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: attachment.RepoID})
+	issue := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{ID: attachment.IssueID})
+	repoOwner := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
+
+	session := loginUser(t, repoOwner.Name)
+	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteIssue)
+
+	filename := "file.bad"
+	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/assets/%d", repoOwner.Name, repo.Name, issue.Index, attachment.ID)
+	req := NewRequestWithValues(t, "PATCH", urlStr, map[string]string{
+		"name": filename,
+	}).AddTokenAuth(token)
+
+	session.MakeRequest(t, req, http.StatusUnprocessableEntity)
+}
+
 func TestAPIDeleteIssueAttachment(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
diff --git a/tests/integration/api_releases_attachment_test.go b/tests/integration/api_releases_attachment_test.go
new file mode 100644
index 0000000000..5df3042437
--- /dev/null
+++ b/tests/integration/api_releases_attachment_test.go
@@ -0,0 +1,40 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+
+	auth_model "code.gitea.io/gitea/models/auth"
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/models/unittest"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/test"
+	"code.gitea.io/gitea/tests"
+)
+
+func TestAPIEditReleaseAttachmentWithUnallowedFile(t *testing.T) {
+	// Limit the allowed release types (since by default there is no restriction)
+	defer test.MockVariableValue(&setting.Repository.Release.AllowedTypes, ".exe")()
+	defer tests.PrepareTestEnv(t)()
+
+	attachment := unittest.AssertExistsAndLoadBean(t, &repo_model.Attachment{ID: 9})
+	release := unittest.AssertExistsAndLoadBean(t, &repo_model.Release{ID: attachment.ReleaseID})
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: attachment.RepoID})
+	repoOwner := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
+
+	session := loginUser(t, repoOwner.Name)
+	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteRepository)
+
+	filename := "file.bad"
+	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/releases/%d/assets/%d", repoOwner.Name, repo.Name, release.ID, attachment.ID)
+	req := NewRequestWithValues(t, "PATCH", urlStr, map[string]string{
+		"name": filename,
+	}).AddTokenAuth(token)
+
+	session.MakeRequest(t, req, http.StatusUnprocessableEntity)
+}
diff --git a/web_src/js/features/comp/QuickSubmit.ts b/web_src/js/features/comp/QuickSubmit.ts
index 3ff29f4fac..385acb319f 100644
--- a/web_src/js/features/comp/QuickSubmit.ts
+++ b/web_src/js/features/comp/QuickSubmit.ts
@@ -1,3 +1,5 @@
+import {querySingleVisibleElem} from '../../utils/dom.ts';
+
 export function handleGlobalEnterQuickSubmit(target) {
   let form = target.closest('form');
   if (form) {
@@ -12,7 +14,11 @@ export function handleGlobalEnterQuickSubmit(target) {
   }
   form = target.closest('.ui.form');
   if (form) {
-    form.querySelector('.ui.primary.button')?.click();
+    // A form should only have at most one "primary" button to do quick-submit.
+    // Here we don't use a special class to mark the primary button,
+    // because there could be a lot of forms with a primary button, the quick submit should work out-of-box,
+    // but not keeps asking developers to add that special class again and again (it could be forgotten easily)
+    querySingleVisibleElem<HTMLButtonElement>(form, '.ui.primary.button')?.click();
     return true;
   }
   return false;
diff --git a/web_src/js/features/repo-issue-edit.ts b/web_src/js/features/repo-issue-edit.ts
index 77a76ad3ca..af97ee4eab 100644
--- a/web_src/js/features/repo-issue-edit.ts
+++ b/web_src/js/features/repo-issue-edit.ts
@@ -3,7 +3,7 @@ import {handleReply} from './repo-issue.ts';
 import {getComboMarkdownEditor, initComboMarkdownEditor, ComboMarkdownEditor} from './comp/ComboMarkdownEditor.ts';
 import {POST} from '../modules/fetch.ts';
 import {showErrorToast} from '../modules/toast.ts';
-import {hideElem, showElem} from '../utils/dom.ts';
+import {hideElem, querySingleVisibleElem, showElem} from '../utils/dom.ts';
 import {attachRefIssueContextPopup} from './contextpopup.ts';
 import {initCommentContent, initMarkupContent} from '../markup/content.ts';
 import {triggerUploadStateChanged} from './comp/EditorUpload.ts';
@@ -77,20 +77,22 @@ async function onEditContent(event) {
     }
   };
 
-  comboMarkdownEditor = getComboMarkdownEditor(editContentZone.querySelector('.combo-markdown-editor'));
-  if (!comboMarkdownEditor) {
-    editContentZone.innerHTML = document.querySelector('#issue-comment-editor-template').innerHTML;
-    const saveButton = editContentZone.querySelector('.ui.primary.button');
-    comboMarkdownEditor = await initComboMarkdownEditor(editContentZone.querySelector('.combo-markdown-editor'));
-    const syncUiState = () => saveButton.disabled = comboMarkdownEditor.isUploading();
-    comboMarkdownEditor.container.addEventListener(ComboMarkdownEditor.EventUploadStateChanged, syncUiState);
-    editContentZone.querySelector('.ui.cancel.button').addEventListener('click', cancelAndReset);
-    saveButton.addEventListener('click', saveAndRefresh);
-  }
-
   // Show write/preview tab and copy raw content as needed
   showElem(editContentZone);
   hideElem(renderContent);
+
+  comboMarkdownEditor = getComboMarkdownEditor(editContentZone.querySelector('.combo-markdown-editor'));
+  if (!comboMarkdownEditor) {
+    editContentZone.innerHTML = document.querySelector('#issue-comment-editor-template').innerHTML;
+    const saveButton = querySingleVisibleElem<HTMLButtonElement>(editContentZone, '.ui.primary.button');
+    const cancelButton = querySingleVisibleElem<HTMLButtonElement>(editContentZone, '.ui.cancel.button');
+    comboMarkdownEditor = await initComboMarkdownEditor(editContentZone.querySelector('.combo-markdown-editor'));
+    const syncUiState = () => saveButton.disabled = comboMarkdownEditor.isUploading();
+    comboMarkdownEditor.container.addEventListener(ComboMarkdownEditor.EventUploadStateChanged, syncUiState);
+    cancelButton.addEventListener('click', cancelAndReset);
+    saveButton.addEventListener('click', saveAndRefresh);
+  }
+
   // FIXME: ideally here should reload content and attachment list from backend for existing editor, to avoid losing data
   if (!comboMarkdownEditor.value()) {
     comboMarkdownEditor.value(rawContent.textContent);
diff --git a/web_src/js/utils/dom.test.ts b/web_src/js/utils/dom.test.ts
index 5c235795fd..d7e3a4939e 100644
--- a/web_src/js/utils/dom.test.ts
+++ b/web_src/js/utils/dom.test.ts
@@ -1,4 +1,4 @@
-import {createElementFromAttrs, createElementFromHTML} from './dom.ts';
+import {createElementFromAttrs, createElementFromHTML, querySingleVisibleElem} from './dom.ts';
 
 test('createElementFromHTML', () => {
   expect(createElementFromHTML('<a>foo<span>bar</span></a>').outerHTML).toEqual('<a>foo<span>bar</span></a>');
@@ -16,3 +16,12 @@ test('createElementFromAttrs', () => {
   }, 'txt', createElementFromHTML('<span>inner</span>'));
   expect(el.outerHTML).toEqual('<button id="the-id" class="cls-1 cls-2" disabled="" tabindex="0" data-foo="the-data">txt<span>inner</span></button>');
 });
+
+test('querySingleVisibleElem', () => {
+  let el = createElementFromHTML('<div><span>foo</span></div>');
+  expect(querySingleVisibleElem(el, 'span').textContent).toEqual('foo');
+  el = createElementFromHTML('<div><span style="display: none;">foo</span><span>bar</span></div>');
+  expect(querySingleVisibleElem(el, 'span').textContent).toEqual('bar');
+  el = createElementFromHTML('<div><span>foo</span><span>bar</span></div>');
+  expect(() => querySingleVisibleElem(el, 'span')).toThrowError('Expected exactly one visible element');
+});
diff --git a/web_src/js/utils/dom.ts b/web_src/js/utils/dom.ts
index a6e0fe2854..e2a4c60e84 100644
--- a/web_src/js/utils/dom.ts
+++ b/web_src/js/utils/dom.ts
@@ -269,8 +269,8 @@ export function initSubmitEventPolyfill() {
  */
 export function isElemVisible(element: HTMLElement): boolean {
   if (!element) return false;
-
-  return Boolean(element.offsetWidth || element.offsetHeight || element.getClientRects().length);
+  // checking element.style.display is not necessary for browsers, but it is required by some tests with happy-dom because happy-dom doesn't really do layout
+  return Boolean((element.offsetWidth || element.offsetHeight || element.getClientRects().length) && element.style.display !== 'none');
 }
 
 // replace selected text in a textarea while preserving editor history, e.g. CTRL-Z works after this
@@ -330,3 +330,10 @@ export function animateOnce(el: Element, animationClassName: string): Promise<vo
     el.classList.add(animationClassName);
   });
 }
+
+export function querySingleVisibleElem<T extends HTMLElement>(parent: Element, selector: string): T | null {
+  const elems = parent.querySelectorAll<HTMLElement>(selector);
+  const candidates = Array.from(elems).filter(isElemVisible);
+  if (candidates.length > 1) throw new Error(`Expected exactly one visible element matching selector "${selector}", but found ${candidates.length}`);
+  return candidates.length ? candidates[0] as T : null;
+}