[PATCH 7/4] For more manual gas pressure details

[Linus Torvalds]

From: Linus Torvalds <torvalds at linux-foundation.org>
Date: Sun, 30 Jul 2017 21:05:48 -0700
Subject: [PATCH 7/4] For more manual gas pressure details

So the manual gas pressure case keeps showing issues, and in many ways it 
really is a fairly complex thing, since it needs interpolation of the 
intermediate pressures - possibly over several gas changes.

So you might have beginning and ending pressures for one cylinder, but
then use another cylinder in between.

We've historically got all the code to do this, but the big rewrite for 
multiple cylinder pressures didn't get all the details right, and so 
here's a few more fixes for the case that was shown by a dive by Robert 
Helling.  Hopefully we're approaching the old code situation, except now 
with concurrent gas pressure handling support.

Reported-by: Robert Helling <helling at atdotde.de>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
---
 core/gaspressures.c | 20 ++++++++++----------
 core/profile.c      |  4 +++-
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/core/gaspressures.c b/core/gaspressures.c
index 13196b61..ce88df04 100644
--- a/core/gaspressures.c
+++ b/core/gaspressures.c
@@ -409,16 +409,6 @@ void populate_pressure_information(struct dive *dive, struct divecomputer *dc, s
 				current->end = pressure;
 		}
 
-		// If we have no pressure information, we will need to
-		// continue with or without a tracking entry. Mark any
-		// existing tracking entry as non-dense, and remember
-		// to fill in interpolated data.
-		if (!pressure) {
-			missing_pr = 1;
-			dense = 0;
-			continue;
-		}
-
 		// We have a final pressure for 'current'
 		// If a gas switch has occurred, finish the
 		// current pressure track entry and continue
@@ -429,6 +419,16 @@ void populate_pressure_information(struct dive *dive, struct divecomputer *dc, s
 			continue;
 		}
 
+		// If we have no pressure information, we will need to
+		// continue with or without a tracking entry. Mark any
+		// existing tracking entry as non-dense, and remember
+		// to fill in interpolated data.
+		if (current && !pressure) {
+			missing_pr = 1;
+			dense = 0;
+			continue;
+		}
+
 		// If we already have a pressure tracking entry, and
 		// it has not had any missing samples, just continue
 		// using it - there's nothing to interpolate yet.
diff --git a/core/profile.c b/core/profile.c
index 7b582741..eccbb561 100644
--- a/core/profile.c
+++ b/core/profile.c
@@ -816,13 +816,15 @@ static void add_plot_pressure(struct plot_info *pi, int time, int cyl, int mbar)
 
 static void setup_gas_sensor_pressure(struct dive *dive, struct divecomputer *dc, struct plot_info *pi)
 {
-	int prev = -1, i;
+	int prev, i;
 	struct event *ev;
 	unsigned int seen[MAX_CYLINDERS] = { 0, };
 	unsigned int first[MAX_CYLINDERS] = { 0, };
 	unsigned int last[MAX_CYLINDERS] = { 0, };
 	struct divecomputer *secondary;
 
+	prev = explicit_first_cylinder(dive, dc);
+	seen[prev] = 1;
 	for (i = 0; i < MAX_CYLINDERS; i++)
 		last[i] = INT_MAX;
 
-- 
2.14.0.rc1.2.g4c8247ec3