fix panic when changing log file to a nonexisting directory (#5132) (#5249)

internal/core/core.go

@@ -1010,15 +1010,31 @@ func (p *Core) closeResources(newConf *conf.Conf, calledByAPI bool) {
 	}
 
 	if closeLogger && p.logger != nil {
-		p.logger.Close()
+		if newConf == nil {
+			p.logger.Close()
+		}
 		p.logger = nil
 	}
 }
 
 func (p *Core) reloadConf(newConf *conf.Conf, calledByAPI bool) error {
+	oldLogger := p.logger
+
 	p.closeResources(newConf, calledByAPI)
+
 	p.conf = newConf
-	return p.createResources(false)
+
+	err := p.createResources(false)
+	if err != nil {
+		p.logger = oldLogger
+		return err
+	}
+
+	if p.logger != oldLogger {
+		oldLogger.Close()
+	}
+
+	return nil
 }
 
 // APIConfigSet is called by api.

internal/core/core_test.go

@@ -132,3 +132,23 @@ func TestCoreHotReloading(t *testing.T) {
 		defer conn.Close()
 	}()
 }
+
+func TestCoreHotReloadingAndLoggerError(t *testing.T) {
+	confPath := filepath.Join(os.TempDir(), "rtsp-conf")
+
+	err := os.WriteFile(confPath, []byte(""),
+		0o644)
+	require.NoError(t, err)
+	defer os.Remove(confPath)
+
+	p, ok := New([]string{confPath})
+	require.Equal(t, true, ok)
+	defer p.Close()
+
+	err = os.WriteFile(confPath, []byte("logDestinations: [file]\n"+
+		"logFile: /nonexisting/nonexist\n"),
+		0o644)
+	require.NoError(t, err)
+
+	p.Wait()
+}