Make sure memory for default_dive_computer_device is allocated

When calling gtk-gui.c:set_default_dive_computer_device(), first
free memory at default_dive_computer_device and then use strdup().

This fixed a case, where after selecting a device for the first time
in the "Download" dialog, then pressing "OK" followed by "Cancel"
(after a device error) the device text is garbled the next time the
dialog is opened.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Use the name "Subsurface" in the "About" dialog

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Prevent a warning when showing the "About" dialog

gtk-gui.c:about_dialog():
Before assigning a pixel buffer to "logo" check if "image"
has a GTK_IMAGE_PIXBUF storage type.

Prevents the following message if the icon file is missing:
Gtk-CRITICAL **: gtk_image_get_pixbuf: assertion

The message that the file is missing is still shown.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Update cylinder info properly

The "cylinders_equal()/copy_cylinders()" functions were buggered, and
only checked (and copied) the cylinder type.  That was on purpose, since
you do want to be able to change the type of a cylinder without changing
the gasmix of the cylinder.

HOWEVER, the reverse is also true: you may want to change the gasmix of
a cylinder without changing the type.

So it's not that the type of the cylinder is special - it's that the
type and the gasmix should be considered separately.

Do that properly for the equipment editing case.

Reported-by: Ďoďo <dodo.sk@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'delmulti' of github.com:neolit123/subsurface

This brings in Lubomir's latest version of the code. This allows deleting
multiple selected dives from the divelist.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Add the ability to create a log file for debugging output

Especially when asking non-developers for help debugging a problem it can
be extremely useful to have debugging output not go to the console but to
a log file instead.

This just adds the infrastructure to create (and close) such a file. No
changes to the debug output are made.

All this is of course #ifdef'ed out.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
First implementation of native Uemis downloader

This includes one major hack that uses a private data structure from
libdivecomputer to allow us to show the Uemis Zurich as one computer the
user can import from.

Once the user has chosen the Uemis we don't use libdivecomputer but our
own downloader. Just like in the libdicecomputer case this runs in its own
thread and updates the import dialog with progress information.

The code also keeps track of the last dive that has been downloaded from a
Uemis computer so we only import new dives on subsequent downloads. And
since the Uemis Zurich gives us its device id, we make this a "per
divecomputer" property for people who dive with multiple Uemis Zurich
computers.

This uses the debugfile infrastructure to allow easily collecting
debugging output - especially on Windows where by default console output
is lost.

Known limitations: when the Uemis runs out of space (it uses its
filesystem for communication with the host computer) we have no graceful
way to reset things. This is why the code doesn't try to download ALL
dives on the computer but instead download them in increments of ten
dives. This clearly needs to be addressed once I understand how to reset
the device.

The Cancel button of the import dialog isn't correctly hooked up, yet.
I still need to figure out how to gracefully shut down a download without
potentially hanging the device.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix stupid packing error on Windows

I guess no one has ever tried to import Uemis dive data under Windows.

The glib-2 libraries for Windows (at least the ones that are part of the
mingw package, but my guess is this is true for all of them), force the
whole program to be compiled with Windows packing rules for structures.
That broke the structure we use for decoding Uemis binary data.

This commit changes the data structure to no longer use unaligned 16bit
values but instead two 8bit values and assemble them in the actual code.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Merge branch 'uemis-native'

This brings in the code to download dive information directly from a Uemis
Zurich dive computer.

The implementation contains a major hack that hooks the uemis code into
the same data structures used to setup libdivecomputer. This gives the
best result for the user, but is not something that I like as a long term
solution as it relies on internal libdivecomputer data structures.
Much improved handling of out of memory errors in the Uemis downloader

Instead of trying to figure out in the GUI code whether to call the
downloader again, the logic was moved into the downloader itself. It now
attempts to deal cleverly with running out of space on the dive computer
filesystem - and in return is able to process the maximum number of dives
(instead of just ten or so at a time).

Even on partial reads before a failure we are able to collect the data
that was completely transferred and report those dives.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Getting ready for the 2.0 release

Changing the version to 2.0-rc1

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Restructure the Uemis native download buffer code

Running under Valgrind showed a couple of silly bugs.

Worse, intentionally running into various error scenarios showed that we
could get the buffer handling in the raw parsing code to break down - we
would fail to process the correctly downloaded files.

To make it easier to get this right I restructured the code to collect the
XML buffer in a different way - this works much better and has stood up
well under testing so far.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>