fix: handle backend issue list regressions

server/db/mysql/group_schema_test.go

@@ -4,6 +4,7 @@ package mysql
 
 import (
 	"database/sql"
+	"os"
 	"strings"
 	"testing"
 
@@ -150,3 +151,23 @@ func TestTenantShardSQL(t *testing.T) {
 		t.Fatalf("tenant shard query rewrote index name: %s", query)
 	}
 }
+
+func TestSharedDBGroupFileLinkIncludesTenantID(t *testing.T) {
+	source, err := os.ReadFile("tenant_groups.go")
+	if err != nil {
+		t.Fatal(err)
+	}
+	body := sourceBetween(t, string(source), "func (a *adapter) TenantGroupFileCreate", "\nfunc (a *adapter) enrichGroupFileFromUpload")
+	for _, required := range []string{
+		"INSERT INTO im_filemsglinks(tenant_id,createdat,fileid,topic)",
+		"SELECT ?,?,?,? WHERE NOT EXISTS",
+		"SELECT 1 FROM im_filemsglinks WHERE tenant_id=? AND fileid=? AND topic=?)",
+	} {
+		if !strings.Contains(body, required) {
+			t.Fatalf("TenantGroupFileCreate shared-db file link must include tenant_id; missing %q", required)
+		}
+	}
+	if strings.Contains(body, "INSERT INTO im_filemsglinks(createdat,fileid,topic)") {
+		t.Fatal("TenantGroupFileCreate must not rely on im_filemsglinks.tenant_id default")
+	}
+}

server/db/mysql/tenant_groups.go

@@ -1132,10 +1132,10 @@ func (a *adapter) TenantGroupFileCreate(id t.TenantID, file *t.GroupFile) (*t.Gr
 					SELECT 1 FROM im_filemsglinks WHERE tenant_id=? AND fileid=? AND topic=?)`,
 				id, now, decodeUID(fid), file.Topic, id, decodeUID(fid), file.Topic)
 		} else {
-			_, err = tx.ExecContext(ctx, `INSERT INTO im_filemsglinks(createdat,fileid,topic)
-				SELECT ?,?,? WHERE NOT EXISTS (
-					SELECT 1 FROM im_filemsglinks WHERE fileid=? AND topic=?)`,
-				now, decodeUID(fid), file.Topic, decodeUID(fid), file.Topic)
+			_, err = tx.ExecContext(ctx, `INSERT INTO im_filemsglinks(tenant_id,createdat,fileid,topic)
+				SELECT ?,?,?,? WHERE NOT EXISTS (
+					SELECT 1 FROM im_filemsglinks WHERE tenant_id=? AND fileid=? AND topic=?)`,
+				id, now, decodeUID(fid), file.Topic, id, decodeUID(fid), file.Topic)
 		}
 		if err != nil {
 			return nil, err