From 9787bb7ac9e446475be1833db7c8d68391331762 Mon Sep 17 00:00:00 2001
From: Jef Driesen <jef@libdivecomputer.org>
Date: Thu, 2 Feb 2023 18:52:35 +0100
Subject: [PATCH] Always include all gas mixes defined in the header

Especially among technical divers, it's not uncommon to carry spare
tanks that will only be used in emergency situations (for example a
rebreather with one or more bailout tanks). Since those gas mixes are
not used throughout the dive, they were also not reported to the
application.

Fixed by reporting all configured gas mixes. Applications can still
obtain the previous result after manually inspecting the gas switch
events in the samples and filtering out the unused gas mixes.

This partially reverts commit c8b166dadbf961e17a9bd1cc28db3d92832ddf72.
---
 src/shearwater_predator_parser.c | 31 ++++++++++++++++++++++++++-----
 1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/src/shearwater_predator_parser.c b/src/shearwater_predator_parser.c
index d0cccb3..1ac89aa 100644
--- a/src/shearwater_predator_parser.c
+++ b/src/shearwater_predator_parser.c
@@ -90,7 +90,8 @@
 #define METRIC   0
 #define IMPERIAL 1
 
-#define NGASMIXES 10
+#define NGASMIXES 20
+#define NFIXED    10
 #define NTANKS    6
 #define NRECORDS  8
 
@@ -421,11 +422,17 @@ shearwater_predator_parser_cache (shearwater_predator_parser_t *parser)
 	unsigned int divemode = M_OC_TEC;
 
 	// Get the gas mixes.
-	unsigned int ngasmixes = 0;
+	unsigned int ngasmixes = NFIXED;
 	shearwater_predator_gasmix_t gasmix[NGASMIXES] = {0};
 	shearwater_predator_tank_t tank[NTANKS] = {0};
 	unsigned int o2_previous = 0, he_previous = 0;
 	unsigned int aimode = AI_OFF;
+	if (!pnf) {
+		for (unsigned int i = 0; i < NFIXED; ++i) {
+			gasmix[i].oxygen = data[20 + i];
+			gasmix[i].helium = data[30 + i];
+		}
+	}
 
 	unsigned int offset = headersize;
 	unsigned int length = size - footersize;
@@ -540,7 +547,18 @@ shearwater_predator_parser_cache (shearwater_predator_parser_t *parser)
 			// Opening record
 			parser->opening[type - LOG_RECORD_OPENING_0] = offset;
 
-			if (type == LOG_RECORD_OPENING_4) {
+			if (type == LOG_RECORD_OPENING_0) {
+				for (unsigned int i = 0; i < NFIXED; ++i) {
+					gasmix[i].oxygen = data[offset + 20 + i];
+				}
+				for (unsigned int i = 0; i < 2; ++i) {
+					gasmix[i].helium = data[offset + 30 + i];
+				}
+			} else if (type == LOG_RECORD_OPENING_1) {
+				for (unsigned int i = 2; i < NFIXED; ++i) {
+					gasmix[i].helium = data[offset + 1 + i - 2];
+				}
+			} else if (type == LOG_RECORD_OPENING_4) {
 				// Log version
 				logversion = data[offset + 16];
 
@@ -678,9 +696,12 @@ shearwater_predator_parser_cache (shearwater_predator_parser_t *parser)
 	parser->logversion = logversion;
 	parser->headersize = headersize;
 	parser->footersize = footersize;
-	parser->ngasmixes = ngasmixes;
+	parser->ngasmixes = 0;
 	for (unsigned int i = 0; i < ngasmixes; ++i) {
-		parser->gasmix[i] = gasmix[i];
+		if (gasmix[i].oxygen == 0 && gasmix[i].helium == 0)
+			continue;
+		parser->gasmix[parser->ngasmixes] = gasmix[i];
+		parser->ngasmixes++;
 	}
 	parser->ntanks = 0;
 	for (unsigned int i = 0; i < NTANKS; ++i) {