From: Keith Packard <keithp@keithp.com>
Date: Wed, 19 May 2021 17:50:22 +0000 (-0700)
Subject: altosdroid: protect USB read/write when connection is null
X-Git-Tag: 1.9.7~1^2~6^2~3
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=9eb0fbd7eff5694064f9d123220b523a98fef0a4

altosdroid: protect USB read/write when connection is null

Check to see if connection is valid before attempting to read/write to
it.

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/altosdroid/app/src/main/java/org/altusmetrum/AltosDroid/AltosUsb.java b/altosdroid/app/src/main/java/org/altusmetrum/AltosDroid/AltosUsb.java
index 35514483..ad47707d 100644
--- a/altosdroid/app/src/main/java/org/altusmetrum/AltosDroid/AltosUsb.java
+++ b/altosdroid/app/src/main/java/org/altusmetrum/AltosDroid/AltosUsb.java
@@ -210,12 +210,16 @@ public class AltosUsb extends AltosDroidLink {
 	}
 
 	int read(byte[] buffer, int len) {
+		if (connection == null)
+			return 0;
 		int ret = connection.bulkTransfer(in, buffer, len, -1);
 		AltosDebug.debug("read(%d) = %d\n", len, ret);
 		return ret;
 	}
 
 	int write(byte[] buffer, int len) {
+		if (connection == null)
+			return 0;
 		int ret = connection.bulkTransfer(out, buffer, len, -1);
 		AltosDebug.debug("write(%d) = %d\n", len, ret);
 		return ret;