From 260c7309da6f43af40dedf927c17e495872e4e3b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Peter=20Gardfj=C3=A4ll?= <peter.gardfjall.work@gmail.com>
Date: Fri, 1 Apr 2022 16:06:02 +0200
Subject: [PATCH 1/2] An attempt to sync a non-mirror repo must give 400 (Bad
 Request)

---
 integrations/api_repo_test.go | 21 +++++++++++++++++++++
 routers/api/v1/repo/mirror.go | 10 ++++++++++
 2 files changed, 31 insertions(+)

diff --git a/integrations/api_repo_test.go b/integrations/api_repo_test.go
index ce1ecb1d43d8a..b585ad15e3a1e 100644
--- a/integrations/api_repo_test.go
+++ b/integrations/api_repo_test.go
@@ -405,6 +405,27 @@ func testAPIRepoMigrateConflict(t *testing.T, u *url.URL) {
 	})
 }
 
+// mirror-sync must fail with "400 (Bad Request)" when an attempt is made to
+// sync a non-mirror repository.
+func TestAPIMirrorSyncNonMirrorRepo(t *testing.T) {
+	defer prepareTestEnv(t)()
+
+	session := loginUser(t, "user2")
+	token := getTokenForLoggedInUser(t, session)
+
+	var repo api.Repository
+	req := NewRequest(t, "GET", "/api/v1/repos/user2/repo1")
+	resp := MakeRequest(t, req, http.StatusOK)
+	DecodeJSON(t, resp, &repo)
+	assert.EqualValues(t, false, repo.Mirror)
+
+	req = NewRequestf(t, "POST", "/api/v1/repos/user2/repo1/mirror-sync?token=%s", token)
+	resp = session.MakeRequest(t, req, http.StatusBadRequest)
+	errRespJSON := map[string]string{}
+	DecodeJSON(t, resp, &errRespJSON)
+	assert.Equal(t, "Repository is not a mirror", errRespJSON["message"])
+}
+
 func TestAPIOrgRepoCreate(t *testing.T) {
 	testCases := []struct {
 		ctxUserID         int64
diff --git a/routers/api/v1/repo/mirror.go b/routers/api/v1/repo/mirror.go
index c9ac3e829230e..e4cae0e3c9308 100644
--- a/routers/api/v1/repo/mirror.go
+++ b/routers/api/v1/repo/mirror.go
@@ -5,8 +5,10 @@
 package repo
 
 import (
+	"errors"
 	"net/http"
 
+	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unit"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/setting"
@@ -48,6 +50,14 @@ func MirrorSync(ctx *context.APIContext) {
 		return
 	}
 
+	if _, err := repo_model.GetMirrorByRepoID(repo.ID); err != nil {
+		if errors.Is(err, repo_model.ErrMirrorNotExist) {
+			ctx.Error(http.StatusBadRequest, "MirrorSync", "Repository is not a mirror")
+			return
+		}
+		ctx.Error(http.StatusInternalServerError, "MirrorSync", err)
+	}
+
 	mirror_service.StartToMirror(repo.ID)
 
 	ctx.Status(http.StatusOK)

From 72c05e5659101ce2e5a8399c7cdfb345bd486ead Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Peter=20Gardfj=C3=A4ll?= <peter.gardfjall.work@gmail.com>
Date: Fri, 1 Apr 2022 16:14:44 +0200
Subject: [PATCH 2/2] add missing return statement

---
 routers/api/v1/repo/mirror.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/routers/api/v1/repo/mirror.go b/routers/api/v1/repo/mirror.go
index e4cae0e3c9308..d7facd24d96cc 100644
--- a/routers/api/v1/repo/mirror.go
+++ b/routers/api/v1/repo/mirror.go
@@ -56,6 +56,7 @@ func MirrorSync(ctx *context.APIContext) {
 			return
 		}
 		ctx.Error(http.StatusInternalServerError, "MirrorSync", err)
+		return
 	}
 
 	mirror_service.StartToMirror(repo.ID)