Improve the `issue_comment` workflow trigger event (#29277)

Fix #29175
Replace #29207

This PR makes some improvements to the `issue_comment` workflow trigger
event.

1. Fix the bug that pull requests cannot trigger `issue_comment`
workflows
2. Previously the `issue_comment` event only supported the `created`
activity type. This PR adds support for the missing `edited` and
`deleted` activity types.
3. Some events (including `issue_comment`, `issues`, etc. ) only trigger
workflows that belong to the workflow file on the default branch. This
PR introduces the `IsDefaultBranchWorkflow` function to check for these
events.

(cherry picked from commit a4fe1cdf38f9a063e44b197ef07e4260f731c919)

Conflicts:
	modules/actions/github.go
	context

2 files changed, 50 insertions, 0 deletions

diff --git a/modules/actions/github.go b/modules/actions/github.go
index d4e559408b..cc04ca5c5c 100644
--- a/modules/actions/github.go
+++ b/modules/actions/github.go
@@ -25,6 +25,45 @@ const (
 	GithubEventSchedule                 = "schedule"
 )
 
+// IsDefaultBranchWorkflow returns true if the event only triggers workflows on the default branch
+func IsDefaultBranchWorkflow(triggedEvent webhook_module.HookEventType) bool {
+	switch triggedEvent {
+	case webhook_module.HookEventDelete:
+		// GitHub "delete" event
+		// https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#delete
+		return true
+	case webhook_module.HookEventFork:
+		// GitHub "fork" event
+		// https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#fork
+		return true
+	case webhook_module.HookEventIssueComment:
+		// GitHub "issue_comment" event
+		// https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#issue_comment
+		return true
+	case webhook_module.HookEventPullRequestComment:
+		// GitHub "pull_request_comment" event
+		// https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_comment-use-issue_comment
+		return true
+	case webhook_module.HookEventWiki:
+		// GitHub "gollum" event
+		// https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#gollum
+		return true
+	case webhook_module.HookEventSchedule:
+		// GitHub "schedule" event
+		// https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#schedule
+		return true
+	case webhook_module.HookEventIssues,
+		webhook_module.HookEventIssueAssign,
+		webhook_module.HookEventIssueLabel,
+		webhook_module.HookEventIssueMilestone:
+		// Github "issues" event
+		// https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#issues
+		return true
+	}
+
+	return false
+}
+
 // canGithubEventMatch check if the input Github event can match any Gitea event.
 func canGithubEventMatch(eventName string, triggedEvent webhook_module.HookEventType) bool {
 	switch eventName {
@@ -75,6 +114,11 @@ func canGithubEventMatch(eventName string, triggedEvent webhook_module.HookEvent
 			return false
 		}
 
+	case GithubEventIssueComment:
+		// https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_comment-use-issue_comment
+		return triggedEvent == webhook_module.HookEventIssueComment ||
+			triggedEvent == webhook_module.HookEventPullRequestComment
+
 	default:
 		return eventName == string(triggedEvent)
 	}
diff --git a/modules/actions/github_test.go b/modules/actions/github_test.go
index 4bf55ae03f..6652ff6eac 100644
--- a/modules/actions/github_test.go
+++ b/modules/actions/github_test.go
@@ -103,6 +103,12 @@ func TestCanGithubEventMatch(t *testing.T) {
 			webhook_module.HookEventCreate,
 			true,
 		},
+		{
+			"create pull request comment",
+			GithubEventIssueComment,
+			webhook_module.HookEventPullRequestComment,
+			true,
+		},
 	}
 
 	for _, tc := range testCases {