Fix issue attachment handling (#24202)

Close #24195

Some of the changes are taken from my another fix
https://github.com/go-gitea/gitea/pull/20147/commits/f07b0de997125c9b79cc5af27966a7cdd1803a4d
in #20147 (although that PR was discarded ....)


The bug is:

1. The old code doesn't handle `removedfile` event correctly
2. The old code doesn't provide attachments for type=CommentTypeReview


This PR doesn't intend to refactor the "upload" code to a perfect state
(to avoid making the review difficult), so some legacy styles are kept.

---------

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

3 files changed, 75 insertions, 81 deletions

diff --git a/models/issues/comment.go b/models/issues/comment.go
index a47dc7c151..c7e815c8b6 100644
--- a/models/issues/comment.go
+++ b/models/issues/comment.go
@@ -52,84 +52,61 @@ func (err ErrCommentNotExist) Unwrap() error {
 // CommentType defines whether a comment is just a simple comment, an action (like close) or a reference.
 type CommentType int
 
-// define unknown comment type
-const (
-	CommentTypeUnknown CommentType = -1
-)
+// CommentTypeUndefined is used to search for comments of any type
+const CommentTypeUndefined CommentType = -1
 
-// Enumerate all the comment types
 const (
-	// 0 Plain comment, can be associated with a commit (CommitID > 0) and a line (LineNum > 0)
-	CommentTypeComment CommentType = iota
-	CommentTypeReopen              // 1
-	CommentTypeClose               // 2
-
-	// 3 References.
-	CommentTypeIssueRef
-	// 4 Reference from a commit (not part of a pull request)
-	CommentTypeCommitRef
-	// 5 Reference from a comment
-	CommentTypeCommentRef
-	// 6 Reference from a pull request
-	CommentTypePullRef
-	// 7 Labels changed
-	CommentTypeLabel
-	// 8 Milestone changed
-	CommentTypeMilestone
-	// 9 Assignees changed
-	CommentTypeAssignees
-	// 10 Change Title
-	CommentTypeChangeTitle
-	// 11 Delete Branch
-	CommentTypeDeleteBranch
-	// 12 Start a stopwatch for time tracking
-	CommentTypeStartTracking
-	// 13 Stop a stopwatch for time tracking
-	CommentTypeStopTracking
-	// 14 Add time manual for time tracking
-	CommentTypeAddTimeManual
-	// 15 Cancel a stopwatch for time tracking
-	CommentTypeCancelTracking
-	// 16 Added a due date
-	CommentTypeAddedDeadline
-	// 17 Modified the due date
-	CommentTypeModifiedDeadline
-	// 18 Removed a due date
-	CommentTypeRemovedDeadline
-	// 19 Dependency added
-	CommentTypeAddDependency
-	// 20 Dependency removed
-	CommentTypeRemoveDependency
-	// 21 Comment a line of code
-	CommentTypeCode
-	// 22 Reviews a pull request by giving general feedback
-	CommentTypeReview
-	// 23 Lock an issue, giving only collaborators access
-	CommentTypeLock
-	// 24 Unlocks a previously locked issue
-	CommentTypeUnlock
-	// 25 Change pull request's target branch
-	CommentTypeChangeTargetBranch
-	// 26 Delete time manual for time tracking
-	CommentTypeDeleteTimeManual
-	// 27 add or remove Request from one
-	CommentTypeReviewRequest
-	// 28 merge pull request
-	CommentTypeMergePull
-	// 29 push to PR head branch
-	CommentTypePullRequestPush
-	// 30 Project changed
-	CommentTypeProject
-	// 31 Project board changed
-	CommentTypeProjectBoard
-	// 32 Dismiss Review
-	CommentTypeDismissReview
-	// 33 Change issue ref
-	CommentTypeChangeIssueRef
-	// 34 pr was scheduled to auto merge when checks succeed
-	CommentTypePRScheduledToAutoMerge
-	// 35 pr was un scheduled to auto merge when checks succeed
-	CommentTypePRUnScheduledToAutoMerge
+	CommentTypeComment CommentType = iota // 0 Plain comment, can be associated with a commit (CommitID > 0) and a line (LineNum > 0)
+
+	CommentTypeReopen // 1
+	CommentTypeClose  // 2
+
+	CommentTypeIssueRef   // 3 References.
+	CommentTypeCommitRef  // 4 Reference from a commit (not part of a pull request)
+	CommentTypeCommentRef // 5 Reference from a comment
+	CommentTypePullRef    // 6 Reference from a pull request
+
+	CommentTypeLabel        // 7 Labels changed
+	CommentTypeMilestone    // 8 Milestone changed
+	CommentTypeAssignees    // 9 Assignees changed
+	CommentTypeChangeTitle  // 10 Change Title
+	CommentTypeDeleteBranch // 11 Delete Branch
+
+	CommentTypeStartTracking    // 12 Start a stopwatch for time tracking
+	CommentTypeStopTracking     // 13 Stop a stopwatch for time tracking
+	CommentTypeAddTimeManual    // 14 Add time manual for time tracking
+	CommentTypeCancelTracking   // 15 Cancel a stopwatch for time tracking
+	CommentTypeAddedDeadline    // 16 Added a due date
+	CommentTypeModifiedDeadline // 17 Modified the due date
+	CommentTypeRemovedDeadline  // 18 Removed a due date
+
+	CommentTypeAddDependency    // 19 Dependency added
+	CommentTypeRemoveDependency // 20 Dependency removed
+
+	CommentTypeCode   // 21 Comment a line of code
+	CommentTypeReview // 22 Reviews a pull request by giving general feedback
+
+	CommentTypeLock   // 23 Lock an issue, giving only collaborators access
+	CommentTypeUnlock // 24 Unlocks a previously locked issue
+
+	CommentTypeChangeTargetBranch // 25 Change pull request's target branch
+
+	CommentTypeDeleteTimeManual // 26 Delete time manual for time tracking
+
+	CommentTypeReviewRequest   // 27 add or remove Request from one
+	CommentTypeMergePull       // 28 merge pull request
+	CommentTypePullRequestPush // 29 push to PR head branch
+
+	CommentTypeProject      // 30 Project changed
+	CommentTypeProjectBoard // 31 Project board changed
+
+	CommentTypeDismissReview // 32 Dismiss Review
+
+	CommentTypeChangeIssueRef // 33 Change issue ref
+
+	CommentTypePRScheduledToAutoMerge   // 34 pr was scheduled to auto merge when checks succeed
+	CommentTypePRUnScheduledToAutoMerge // 35 pr was un scheduled to auto merge when checks succeed
+
 )
 
 var commentStrings = []string{
@@ -181,7 +158,23 @@ func AsCommentType(typeName string) CommentType {
 			return CommentType(index)
 		}
 	}
-	return CommentTypeUnknown
+	return CommentTypeUndefined
+}
+
+func (t CommentType) HasContentSupport() bool {
+	switch t {
+	case CommentTypeComment, CommentTypeCode, CommentTypeReview:
+		return true
+	}
+	return false
+}
+
+func (t CommentType) HasAttachmentSupport() bool {
+	switch t {
+	case CommentTypeComment, CommentTypeCode, CommentTypeReview:
+		return true
+	}
+	return false
 }
 
 // RoleDescriptor defines comment tag type
@@ -1039,7 +1032,7 @@ func (opts *FindCommentsOptions) ToConds() builder.Cond {
 	if opts.Before > 0 {
 		cond = cond.And(builder.Lte{"comment.updated_unix": opts.Before})
 	}
-	if opts.Type != CommentTypeUnknown {
+	if opts.Type != CommentTypeUndefined {
 		cond = cond.And(builder.Eq{"comment.type": opts.Type})
 	}
 	if opts.Line != 0 {
diff --git a/models/issues/comment_test.go b/models/issues/comment_test.go
index f1232729f1..43bad1660f 100644
--- a/models/issues/comment_test.go
+++ b/models/issues/comment_test.go
@@ -64,8 +64,9 @@ func TestFetchCodeComments(t *testing.T) {
 }
 
 func TestAsCommentType(t *testing.T) {
-	assert.Equal(t, issues_model.CommentTypeUnknown, issues_model.AsCommentType(""))
-	assert.Equal(t, issues_model.CommentTypeUnknown, issues_model.AsCommentType("nonsense"))
+	assert.Equal(t, issues_model.CommentType(0), issues_model.CommentTypeComment)
+	assert.Equal(t, issues_model.CommentTypeUndefined, issues_model.AsCommentType(""))
+	assert.Equal(t, issues_model.CommentTypeUndefined, issues_model.AsCommentType("nonsense"))
 	assert.Equal(t, issues_model.CommentTypeComment, issues_model.AsCommentType("comment"))
 	assert.Equal(t, issues_model.CommentTypePRUnScheduledToAutoMerge, issues_model.AsCommentType("pull_cancel_scheduled_merge"))
 }
diff --git a/models/issues/issue.go b/models/issues/issue.go
index 5836030476..4f8e9e161d 100644
--- a/models/issues/issue.go
+++ b/models/issues/issue.go
@@ -269,7 +269,7 @@ func (issue *Issue) LoadPullRequest(ctx context.Context) (err error) {
 }
 
 func (issue *Issue) loadComments(ctx context.Context) (err error) {
-	return issue.loadCommentsByType(ctx, CommentTypeUnknown)
+	return issue.loadCommentsByType(ctx, CommentTypeUndefined)
 }
 
 // LoadDiscussComments loads discuss comments