Dive information: fix surface interval calculation

The old surface interval calculation had fundamental issues:

1) process_all_dives(), which calculates the statistics over *all*
   dives was used to get the pointer to the previous dive.
2) If two dives in the table had the same time, one of those would
   have been considered the "previous" dive.
3) If the dive, for which the surface interval is calculated is
   not yet in the table, no previous dive would be determined.

Fix all this by creating a get_surface_interval() function and
removing the "get previous dive" functionality of process_all_dives().
Remove the process_all_dives() call from TabDiveInformation::updateData().

Reported-by: Jan Mulder <jlmulder@xs4all.nl>
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

1 files changed, 3 insertions, 6 deletions

diff --git a/desktop-widgets/tab-widgets/TabDiveInformation.cpp b/desktop-widgets/tab-widgets/TabDiveInformation.cpp
index a4f8f455f..aff781a3b 100644
--- a/desktop-widgets/tab-widgets/TabDiveInformation.cpp
+++ b/desktop-widgets/tab-widgets/TabDiveInformation.cpp
@@ -77,12 +77,9 @@ void TabDiveInformation::updateData()
 	ui->diveTimeText->setText(get_dive_duration_string(displayed_dive.duration.seconds, tr("h"), tr("min"), tr("sec"),
 			" ", displayed_dive.dc.divemode == FREEDIVE));
 
-	struct dive *prevd;
-	process_all_dives(&displayed_dive, &prevd);
-
-	if (prevd)
-		ui->surfaceIntervalText->setText(get_dive_surfint_string(displayed_dive.when - (dive_endtime(prevd)), tr("d"), tr("h"), tr("min")));
-
+	timestamp_t surface_interval = get_surface_interval(displayed_dive.when);
+	if (surface_interval >= 0)
+		ui->surfaceIntervalText->setText(get_dive_surfint_string(surface_interval, tr("d"), tr("h"), tr("min")));
 	else
 		ui->surfaceIntervalText->clear();