ArduPilot/ardupilot

nmea output code should use fixed buffer and fix snprintf issues

Open

#12,514 opened on Oct 8, 2019

View on GitHub
 (5 comments) (0 reactions) (0 assignees)C++ (9,336 stars) (15,603 forks)batch import
BUGLibrarygood first issue

Description

The AP_NMEA_Output code should allocate buffers once for max size of strings, and also needs to fix the use of snprintf for the lng_string to ensure it doesn't end up with an unterminated string in %s for next printf

Contributor guide

Tech stack
cpp
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
C++ programmingsnprintf usagebuffer allocation conceptsArduPilot coding style
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45
Research direction
Examine the AP NMEA Output code, specifically the buffer allocation and snprintf calls. The issue mentions using fixed buffers for maximum string sizes and fixing the lng string snprintf to avoid unterminated strings. Review the existing code in libraries/AP NMEA Output/ for current implementation. Check comments for any additional guidance. Ensure the fix is tested with NMEA output scenarios.