contrib: notmuch-pick: add tests

The test should be run using the wrapper run-tests.sh.  This links
the tests into the normal notmuch TEST_DIRECTORY and runs them from
there. After the test is complete then the links are removed.
test: Produce useful output when the HTML with images test fails

Previously, this would simply indicate that the grep failed without
any indication of the Emacs output it failed on.  Now we take
advantage of the test framework's handling of stdout to display the
incorrect Emacs output if the test fails.
test: always source test-lib.sh as ./test-lib.sh

There are currently 45 TESTS scripts. 36 of those load
test-lib.sh using '. ./test-lib.sh' and 9 '. test-lib.sh'.

In latter case test-lib.sh is first searched from directories
in PATH (posix) and then from current directory (bash feature).

Changed the 9 files to execute '. ./test-lib.sh'. The test-lib.sh
should never be loaded from directory in PATH.
notmuch-show.el: import calendar data with public function after CR removal

notmuch-get-bodypart-content provides raw data to its caller so
that it can be stored verbatim whenever needed. icalendar functions
expect Emacs to do EOL conversion for the data given to these. Therefore
it the CRLF -> LF conversion is now done explicitly.

The calls to private functions icalendar--convert-ical-to-diary and
icalendar--read-element are replaced with call to public function
icalendar-import-buffer.
notmuch-show.el: handle the case where icalendar-import-buffer returns nil

icalendar-import-buffer can fail by an error signal (which have been
witnessed) but according to its docstring it can also return nil
when failing (it returns t when succeeding).

Now that the error is caught by the caller of notmuch-show-inset-part-*
functions in case icalendar-import-buffer returns nil an explicit
error is signaled and unwind-protect takes care of deleting the
temporary file (just in case, it is usually not written to the fs yet).
test: factor out part of test-lib.sh into test-lib-common.sh

The idea is to use some of the simpler parts of the test suite
infrastructure to help run performance tests.
test: initial performance testing infrastructure

This is not near as fancy as as the unit tests, on the theory that
the code should typically be crashing when performance tuning.
Nonetheless, there is plenty of room for improvement.  Several more of
the pieces of the test infrastructure (e.g. the option parsing) could
be factored out into test/test-lib-common.sh
test: Test notmuch new for single-message mbox

We support this for historical reasons.
test: Test for ignoring multi-message mbox

This test is currently broken.  Note that its brokenness cascades and
causes the next test to fail as well (because notmuch incorrectly
indexes the mbox file).
lib: Reject multi-message mboxes and deprecate single-message mbox

Previously, we would treat multi-message mboxes as one giant email,
which, besides the obvious incorrect indexing, often led to
out-of-memory errors for archival mboxes.  Now we explicitly reject
multi-message mboxes.  For historical reasons, we retain support for
single-message mboxes, but official deprecate this behavior.
test/emacs: test saving of attachment containing 8bit octets

This test catches the case 8bit octets in an attachment gets converted
or lost when saving attachment to the file.
This test is marked known broken.
emacs: less guessing of character set in messages

The macro with-current-notmuch-show-message executes command
`notmuch show --format=raw id:...` which just outputs the contents
of the mail file verbatim (into temporary buffer). In case e.g. utf-8
locale is used the temporary buffer has buffer-file-coding-system as
utf-8. In this case Emacs converts the data to multibyte format, guessing
that input is in utf-8.
However, the "raw" (MIME) message may contain octet data in any other
8bit format, and as no (MIME-)content spesific handling to the message
is done at this point, conversion to other formats may lose information.
By setting coding-system-for-read 'no-conversion drops the conversion part
and makes this handle input as notmuch-get-bodypart-internal() does.
This marks the broken test in previous change fixed.
test: Add a test for skipping ignored broken symlinks

Currently marked as broken because we abort on broken symlinks, even
if they are in the ignore list.
new: Skip ignored broken symlinks

We now test for user ignore patterns before attempting to determine if
a directory entry is itself a directory.  As a result, we no longer
abort for broken symlinks if the user has explicitly ignored them.

This fixes the test added in the previous patch.  It also slightly
changes the debug output checked by another test of ignores.
test: Quote $output in calls to test_expect_equal

Previously, many tests in emacs-subject-to-filename didn't quote the
$output argument to test_expect_equal.  As a result, if $output was
empty, test_expect_equal would be passed only one argument and would
abort the entire test script.  By quoting the argument, we ensure
test_expect_equal will always receive two arguments.
test: Make the emacsclient binary user-configurable

And require that if TEST_EMACS is specified, so is TEST_EMACSCLIENT.

Previously, the test framework always used "emacsclient", even if the
Emacs in use was overridden by TEST_EMACS.  This causes problems if
both Emacs 23 and Emacs 24 are installed, the Emacs 23 emacsclient is
the system default, but TEST_EMACS is set to emacs24.  Specifically,
with an Emacs 24 server and an Emacs 23 client, emacs tests that run
very quickly may produce no output from emacsclient, causing the test
to fail.

The Emacs server uses a very simple line-oriented protocol in which
the client sends a request to evaluate an expression and the server
sends a request to print the result of evaluation.  Prior to Emacs bzr
commit 107565 on March 11th, 2012 (released in Emacs 24.1), if
multiple commands were sent to the emacsclient between when it sent
the evaluation command and when it entered its receive loop, it would
only process the first response command, ignoring the rest of the
received buffer.  This wasn't a problem with the Emacs 23 server
because it sent only the command to print the evaluation result.
However, the Emacs 24 server first sends an unprompted command
specifying the PID of the Emacs server, then processes the evaluation
request, then sends the command to print the result.  If the
evaluation is fast enough, it can send both of these commands before
emacsclient enters the receive loop.  Hence, if an Emacs 24 server is
used with an Emacs 23 emacsclient, it may miss the response printing
command, ultimately causing intermittent notmuch test failures.
test: Abort driver if a test script aborts

Previously, if a test script aborted (e.g., because it passed too few
arguments to a test function), the test driver loop would simply
continue on to the next test script and the final results would
declare that everything passed (except that the test count would look
suspiciously low, but maybe you just misremembered how many tests
there were).

Now, if a test script exits with a non-zero status and did not produce
a final results file, we propagate that failure out of the driver loop
immediately.

To keep this simple, this patch removes the PID from the test-results
file name.  This PID was inherited from the git test system and seems
unnecessary, since the file name already includes the name of the test
script and the test-results directory is created anew for each run.
test: Use associative arrays to track external prereqs

Previously, the test framework generated a variable name for each
external prereq as a poor man's associative array.  Unfortunately,
prereqs names may not be legal variable names, leading to
unintelligible bash errors like
  test_missing_external_prereq_emacsclient.emacs24_=t: command not found

Using proper associative arrays to track prereqs, in addition to being
much cleaner than generating variable names and using grep to
carefully construct unique string lists, removes restrictions on
prereq names.
test: Don't print 'nil' at the beginning of emacs-subject-to-filename
performance-test/README: update instructions for fetching corpus.

It turns out not everybody on the planet has my gpg key.