cmd/syncthing: Improve "cli debug file" handling

Proper URL encoding, and return a sensible error when it's not found.

cmd/syncthing/cli/client.go

@@ -134,9 +134,11 @@ func (c *apiClient) Post(url, body string) (*http.Response, error) {
 	return c.Do(request)
 }
 
+var errNotFound = errors.New("invalid endpoint or API call")
+
 func checkResponse(response *http.Response) error {
 	if response.StatusCode == http.StatusNotFound {
-		return errors.New("invalid endpoint or API call")
+		return errNotFound
 	} else if response.StatusCode == http.StatusUnauthorized {
 		return errors.New("invalid API key")
 	} else if response.StatusCode != http.StatusOK {

cmd/syncthing/cli/debug.go

@@ -8,6 +8,7 @@ package cli
 
 import (
 	"fmt"
+	"net/url"
 
 	"github.com/urfave/cli"
 )
@@ -35,7 +36,10 @@ var debugCommand = cli.Command{
 
 func debugFile() cli.ActionFunc {
 	return func(c *cli.Context) error {
-		return indexDumpOutput(fmt.Sprintf("debug/file?folder=%v&file=%v", c.Args()[0], normalizePath(c.Args()[1])))(c)
+		query := make(url.Values)
+		query.Set("folder", c.Args()[0])
+		query.Set("file", normalizePath(c.Args()[1]))
+		return indexDumpOutput("debug/file?" + query.Encode())(c)
 	}
 }
 

cmd/syncthing/cli/utils.go

@@ -48,6 +48,9 @@ func indexDumpOutput(url string) cli.ActionFunc {
 			return err
 		}
 		response, err := client.Get(url)
+		if errors.Is(err, errNotFound) {
+			return errors.New("not found (debugging disabled or folder/file not in database)")
+		}
 		if err != nil {
 			return err
 		}