From: Keith Packard <keithp@keithp.com>
Date: Thu, 20 Jun 2024 22:35:38 +0000 (-0700)
Subject: altoslib: Check for negative tick wrap when importing flight records
X-Git-Tag: 1.9.19~1^2~14^2
X-Git-Url: https://git.gag.com/?a=commitdiff_plain;h=3bc1ab0046c4dbebbde8557d3a1f45707aaefa42;p=fw%2Faltos

altoslib: Check for negative tick wrap when importing flight records

If the tick count wraps just as boost is detected, there may be some
data records on the device with large tick values which are recorded
after the AO_FLIGHT record. Check for these in two places which manage
16-bit tick values by wrapping tick values to negative numbers in
those cases.

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

diff --git a/altoslib/AltosCalData.java b/altoslib/AltosCalData.java
index c90534a9..53e3b8fb 100644
--- a/altoslib/AltosCalData.java
+++ b/altoslib/AltosCalData.java
@@ -202,9 +202,12 @@ public class AltosCalData {
 	public void set_tick(int tick) {
 		if (tick != AltosLib.MISSING) {
 			if (prev_tick != AltosLib.MISSING) {
-				while (tick < prev_tick - 1000) {
+				while (tick < prev_tick - 32767) {
 					tick += 65536;
 				}
+				while (tick > prev_tick + 32767) {
+					tick -= 65536;
+				}
 			}
 			if (first_tick == AltosLib.MISSING)
 				first_tick = tick;
diff --git a/altoslib/AltosEepromRecordSet.java b/altoslib/AltosEepromRecordSet.java
index 8f3fa459..f0819a81 100644
--- a/altoslib/AltosEepromRecordSet.java
+++ b/altoslib/AltosEepromRecordSet.java
@@ -138,6 +138,8 @@ public class AltosEepromRecordSet implements AltosRecordSet {
 			} else {
 				while (t < tick - 32767)
 					t += 65536;
+				while (t > tick + 32767)
+					t -= 65536;
 				tick = t;
 			}
 			record.wide_tick = tick;