api: fix setting default parameters when creating a path (#1853) (#1905)

this fixes a regression introduced in v0.23.0.

internal/core/api.go

@@ -346,6 +346,10 @@ func (a *api) onConfigPathsAdd(ctx *gin.Context) {
 	}
 
 	newConfPath := &conf.PathConf{}
+
+	// load default values
+	newConfPath.UnmarshalJSON([]byte("{}"))
+
 	fillStruct(newConfPath, in)
 
 	newConf.Paths[name] = newConfPath

internal/core/api_test.go

@@ -148,10 +148,16 @@ func TestAPIConfigPathsAdd(t *testing.T) {
 		"sourceOnDemand": true,
 	}, nil)
 
-	var out map[string]interface{}
+	var out struct {
+		Paths map[string]struct {
+			Source                     string `json:"source"`
+			SourceOnDemandStartTimeout string `json:"sourceOnDemandStartTimeout"`
+		} `json:"paths"`
+	}
+
 	httpRequest(t, hc, http.MethodGet, "http://localhost:9997/v2/config/get", nil, &out)
-	require.Equal(t, "rtsp://127.0.0.1:9999/mypath",
-		out["paths"].(map[string]interface{})["my/path"].(map[string]interface{})["source"])
+	require.Equal(t, "rtsp://127.0.0.1:9999/mypath", out.Paths["my/path"].Source)
+	require.Equal(t, "10s", out.Paths["my/path"].SourceOnDemandStartTimeout)
 }
 
 func TestAPIConfigPathsEdit(t *testing.T) {