Add api subcommand for arbitrary api calls not covered by existing subcommands (#879)

Reviewed-on: https://gitea.com/gitea/tea/pulls/879
Co-authored-by: techknowlogick <techknowlogick@gitea.com>
Co-committed-by: techknowlogick <techknowlogick@gitea.com>

main.go

@@ -16,7 +16,7 @@ import (
 func main() {
 	app := cmd.App()
 	app.Flags = append(app.Flags, debug.CliFlag())
-	err := app.Run(context.Background(), os.Args)
+	err := app.Run(context.Background(), preprocessArgs(os.Args))
 	if err != nil {
 		// app.Run already exits for errors implementing ErrorCoder,
 		// so we only handle generic errors with code 1 here.
@@ -24,3 +24,17 @@ func main() {
 		os.Exit(1)
 	}
 }
+
+// preprocessArgs normalizes command-line arguments.
+// Converts "-o-" to "-o -" for the api command's output flag.
+func preprocessArgs(args []string) []string {
+	result := make([]string, 0, len(args)+1)
+	for _, arg := range args {
+		if arg == "-o-" {
+			result = append(result, "-o", "-")
+		} else {
+			result = append(result, arg)
+		}
+	}
+	return result
+}