Just a formal correction for the previous commit. Enclose variables
within {} signs.

Running `thunderbird -g` produces the following error:

    INFO  -> Starting Thunderbird with GDB ...
    INFO  -> LANG= /usr/bin/gdb -ex "handle SIG38 nostop" -ex "handle SIGPIPE nostop" -ex "run" /usr/lib/thunderbird/thunderbird
    /usr/bin/thunderbird: line 254: /usr/bin/gdb -ex "handle SIG38 nostop" -ex "handle SIGPIPE nostop" -ex "run" /usr/lib/thunderbird/thunderbird : No such file or directory

This occurs because exec is passed a single argument, which it
interprets as a file name that does not exist.  Instead, use the
following steps:

1. Build a command string which combines ${TB_GDB_DEFAULT_OPTS} and
   ${TB_ARGS[@]} (using `printf ' %q'`).
2. Print the command string with output_info.
3. Run it using `eval` (for word splitting) and `exec` (to replace the
   shell process with gdb, as before).

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>

Doing some prefixing of local variables that using really generic names
otherwise which might conflicht in case they have been set outside of
the context from this script.

If the user who launched thunderbird had exported DEBUG=1 the launcher
didn't launch anything (because DEBUGGER was not set).

Closes: #960230

We need to escape the arguments for the -ex option while calling gdb.

Closes: #976979

Thunderbird >= 68.x use some other type functionality to include sytem
wide installed dictionaries.
We need to give the variable DICPATH the path to the folder where the
dictionaries can be found.

Thanks to Raphaël Bleuse for the pointer!

Closes: #944295

The old wrapper script run-mozilla.sh isn't shipped any longer in
Thunderbird. This requires a modification to the call of the GDB
debugger. Other debugger than GDB are still not supported.

The root of #882122 wasn't related to thunderbird internal issues but to
the apparmor profile or AppArmor itself. With a disabled apparmor
profile the original issue isn't happen. The previous changes can tack
back.

This reverts commit 6dd6fdbe.

After commit 611a7047 we build now a
package thunderbird-dbgsym. So we need to search for this package
instead of the old dbg package.

Upstream is building the binary 'thunderbird' but install this as
'thunderbird-bin' and is doing later some magic to also copy
'thunderbird-bin' back into 'thunderbid' inside the installation folder.
It looks more naturally Thunderbird needs to be started by calling
thunderbird-bin in the wrapper script, particularly as the binary is
doing some self checking how it was called.
Some users reported they had issues to start Thunderbird by calling

  /usr/lib/thunderbird/thunderbird

but did have success by calling instead

  /usr/lib/thunderbird/thunderbird-bin

The starting wrapper script got modified in that way to always call now
'thunderbird-bin'.

Closes: #882122

This avoids a not needed subprocess call in the running shell.

Closes: #858100

Abort on errors.

so it's simpler to test.

We need to adjust the check for the thunderbird-dbg package, the
original aproach isn't usable any longer. Using instead a dpkg query to
detect if thunderbird-dbg is installed.

Closes: #858804

We don't need to error out if the variables ${ID_PROFILE_FOLDER} and
${TB_PROFILE_FOLDER} are pointing to the same direction. The direction
itself maybe than a symlink again but this doesn't matter then.

Closes: #858771

The approach in c2a1d77d wasn't the
right attempt, as explained by Simon and Daniel in #855334 the best
solution is to use a Bash array that's taken as argument for the TB
binary call.
It's not only more simple, it's also more secure than to use eval for
variable expansion, really bing thanks for explaining this potential
security problem goes out to Simon here! Really appreciated.
But also thanking Daniel for providing a patch with the needed
structural changes!

Given arguments that are not targeted for the wrapper script itself
needs to through the script and passed as given to the final call of the
Thunderbird binary. This needs the usage of the extra function call
'eval' to expand the given arguments first.

We also parse the arguments as a list instead on based the given
argument count. This saves a little bit time, the can loop directly
through the elements of list.
While looping through the arguments we search for escaped arguments and
"restore" this escaping as it is removed bx the shell. Doing this also
for arguments that containing some other special characters like equal
signs and commas. Some possible arguments for the thunderbird binary use
them. For example

  thunderbird -compose "to='recipient@tld.org','attachment=some.file'"

And doing some more escaping of used variables inside the script.

Closes: #855334

A stupid error happen in the if statement while checking for existing
folders .icedove and .thunderbird doing work for commit
c9e5b708

The comment behind the if check is of course intepreted by the Bash as
we have a backslash '\' in the if condition to ignore the line break
here. By this the check wasn't working correctly and assumes the check
is failing and informs the user for a not valid folder situation.

Closes: #857029, #857032, #857098, #857112

To give users a chance to add e.g. --verbose option after typing
--show-backup we need to first looping all given options within the case
loop and decide later given on the flags what to do.

The two helper scripts got completely restructured to fit into the idea
we do a symlinking of .thunderbird to .icedove in the users home.
To goal this the various steps got break of into subfunctions that are
called from the main wrapper helper script /usr/bin/thunderbird.

Also adding some extra wrapper option to get the fixing for the MIME
part also available ouside the profile adption. This commit is made also
from contribution of Debian fellows.
Thanks go out to Jens Reyer who contributed not only patches but also
checking the script against the shellcheck tool and by doing the needed
testing of this whole stuff!

The logic for the adoption is hopefully simple.
If there is no folder or already symlinked ~/.thunderbird folder to
.icedove we can simply create the link to ~/.icedove.
If we check there is a existing symlink ~/.thunderbird and isn't pointing
to ~/.icedove we error out then.

Closes: #855265, #855391, #855501, #856490

Using the option seperator '--' in the thunderbird-wrapper script isn't
usable, it breaks other scripts and caller functions.
To not break other stuff removing the getopt functionality as we need to
collect the possible mixed up options given to the wrapper script and
split them of.

Thanks Guido Günther for getting the basic while loop for handling this.

Closes: #855872

We can improve the the usage of the possible X11 dialogs if we add some
sanity checks and also adding a fallback mechanism if some call to
kdialog or zenity is failing.

To improve the readability of the starting wrapper script let's split
off all the helper stuff like local functions, static strings and some
checks. The plain wrapper script for /u/b/thunderbird get consolidated
and compacted by this.

Also adding the Mate DE to the detected environments we can run on, as
suggested by #855286.
Adding the 'mate' string to the zenity call if detected. We still need
to add some sanity checks if zenity or kdialog available.

Closes: #855286

The old behavior of passing all arguments into a single string by using
the variable THUNDERBIRD_OPTIONS isn't working well and not as expected.
We can instead use $@ directly.

Thanks dkg for preparing that fix!

Closes: #855334

Moving the migration of possible existing mimeapp.list files within a
user profile into a extra function.
We also need to catch up all old userapp-Icedove-*.desktop files and
remove them.

Closes: #849592

Inform the user about the start of the user profile(s) so it doesn't
look like the machine is frozen or is doing nothing while the migration
is ongoing.

Closes: #854488

All tiling window manager wont have a file ${HOME}/.config/mimeapps.list
and would break as we assume the file must be there. Catching this by
simple checking of existence before continue at this part.

We hopefully catch any error and report it to the user. So a running
script with error handling is more useful than a cryptic error message
with instant script exit.

It's also a good idea to change existing MIME associations with the
icedove desktop within $(HOME)/.config/mimeapps.list as Laurent
Bigonville pointed out.

Improving the script a bit more so it will not going further and try
things which can lead to a inconsist old profile folder depending on
ignoring the first error.

Closes: #850864

The file 'mimeTypes.rdf' may have registered /usr/bin/iceweasel for
various application like http and https. This is no problem as long as
the user isn't removing the transitional iceweasel package which is
providing a symlink from /usr/bin/iceweasel -> /usr/bin/firefox.

So this commit is fixing this by changing all old entries for
/usr/bin/iceweasel with /usr/bin/x-www-browser which is pointing to the
prefered browser. This is only done while the profile migration is done.
If a user isn't using this automatism and is moving the profile folder
by hand the modifying of 'mimeTypes.rdf' has to also done manually.

Thanks to Jens Reyer who figured this problem and the solution out!

Closes: #837516

Because of the de-branding the profile for Thunderbird has changed back
to the Mozilla default $HOME/.thunderbird.

Related to the old branded binary name Icedove the profile folder
$HOME/.icedove was previously used. To get a uninterrupted workflow for
the user while going back to a Thunderbird package we have to take care
about the profile migration to the new profile folder.

This commit creates a wrapper script that will do this migration of the
user data. It's purpose is to act as a wrapper while calling
/usr/lib/thunderbird/thunderbird through /user/bin/thunderbird.
It will also handle a easier handling for creating gdb logs if needed.
Other debuggers can be added to but not yet or probably never. Right now
we never had the need to provide a valgrind build of Icedove or
Thunderbird. Any help is appreciated here.