This improves the function documentation for many interactive
commands, either by improving their documentation string where the
improvement also makes sense for programmatic use or by adding a
'notmuch-doc property where it doesn't.
For nearly all commands that support a prefix argument, this adds a
'notmuch-prefix-doc property to document their prefixed behavior This
omits prefix documentation for a few commands where I thought the
prefixed behavior was too obscure (or too complex to fit in one line).
The only user-visible effect of this should be that "G" now works in
show mode (previously it was unbound for no apparent reason).
This shared keymap gives us one place to put global commands, which
both forces us to think about what commands should be global, and
ensures their bindings can't diverge (like the missing "G" in show).
This unifies the various refresh and poll-and-refresh functions we
have for different modes. Now all modes bind "=" and "G" (except
show, which doesn't bind "G" for some reason) to
`notmuch-refresh-this-buffer' and
`notmuch-poll-and-refresh-this-buffer', respectively.
When text/html parts include images as multipart/related and the
text/plain alternative is used these images can be completely hidden
with no easy way to access them or even find out that they are there.
Make notmuch-show-insert-part-multipart/related add buttons for all
parts, the first one visible the rest hidden.
The lazy part handler had a bug that it allowed the button to be
toggled to be specified. During toggling it needs to save and restore
the text-properties for the button but it actually saved the text
properties at point rather than from the button.
In almost all cases this didn't matter as as point had the same text
properties as the button. However, it is a bug and did cause incorrect
behaviour in some cases: see id:87txhz14z6.fsf@qmul.ac.uk for details.
In reply, insert quotable parts using notmuch-show-insert-bodypart
instead of calling notmuch-mm-display-part-inline directly to render
the quoted parts as they are rendered in show view.
We use a temp buffer to not leak text properties from the show
renderer into the reply. This way we also don't need to worry about
narrowing or point placement. Credits to Mark Walters
<markwalters1009@gmail.com> and Austin Clements <amdragon@MIT.EDU> for
getting this part straight.
The notable change is that replies to text/calendar parts quote the
pretty printed output of icalendar-import-buffer rather than the ugly
raw vcalendar.
notmuch-show.el and notmuch.el had 3 duplicate, identical functions:
notmuch-foreach-mime-part, notmuch-count-attachments and
notmuch-save-attachments. Now these functions in notmuch-show.el
are replaced with declare-functions pointing to "notmuch"(.el).
Notmuch puts attachments in as declared content-type except when the
content-type is application/octet-stream it tries to guess the type
from the filename/extension. This means that viewing a pdf (for
example) which is sent as application/octet-strem invokes the pdf
viewer rather than just offering to save the part.
Recent changes to the attachment handling (commit 1546387d) changed
(broke) this. This patch stores the calculated mime-type with the part
and changes the attachment part handlers can use it instead.
Notmuch cli provides all structured data previously provided
in json format now in s-expression format, rendering all current
json functionality obsolete.
This removes the v command, since we now have much nicer part commands,
and deprecates the underlying notmuch-show-view-all-mime-parts. This
also means that people who try using the old unprefixed 'v' command on
a part button will no longer be greeted by ALL of their parts popping
up.
Previously the query string for piping a message to a command was
"Pipe message to command: " regardless of whether the function was
called with a prefix argument (which pipes all open messages to the
command). This patch modifies the `interactive' command to reflect
this.
This adds the actual code to do the lazy insertion of hidden parts.
We use a memory inefficient but simple method: when we come to insert
the part if it is hidden we just store all of the arguments to the
part insertion function as a button property. This means when we want
to show the part we can just resume where we left off.
One thing is that we can't tell if a lazy part will produce text until
we try to render it so when unhiding a part we check to see if it
rendered; if not we invoke the default part handler (e.g. an external
viewer).
Also, we would like to insert the lazy part at the start of the line
after the part button. But if this line has some text properties
(e.g. the colours for a following message header) then the lazy part
gets these properties. Thus we start at the end of the part button
line, insert a newline, insert the lazy part, and then delete the
extra newline at the end of the part.
Previously, whether a part was hidden or shown was recorded in the
invisibility/visibility of the part overlay. Since we are going to
have lazily rendered parts with no overlay store the hidden/shown
state in the part button itself.
Additionally, in preparation for the invisible part handling move the
actual hiding of the hidden parts to insert-bodypart from
create-part-overlays.
Finally, we will need to know whether a part-insertion has done
anything (it won't if the invisible part cannot be displayed by emacs)
so we slightly rejig the code order in
notmuch-show-toggle-part-invisibility to make it easier for the
function to set an appropriate return value.
Previously each of the part insertion handlers inserted the part
button themselves. Move this up into
notmuch-show-insert-bodypart. Since a small number of the handlers
modify the button (the encryption/signature ones) we need to pass the
header button as an argument into the individual part insertion
handlers. However, the declared-type argument was only used for the
text for the part buttons we can now omit it.
The patch is large but mostly simple. The only things of note are that
we let the text/plain handler applies notmuch-wash to the whole part
including the part button. In particular, notmuch-wash removes leading
blank lines from a text/plain part, but since the button is counted as
part of the part this does not happen with text/plain buttons that
have a button. This is probably a bug in notmuch-wash but changing it
does make several tests fail (that rely on this blank line) so, for
the moment, keep the old behaviour.
Earlier patches have moved the handling of wash fake inline patch
parts to insert-bodypart so we can drop the function
notmuch-show-insert-part-inline-patch-fake-part
Previously, we simply called pushnew to add :notmuch-part to the
front-sticky and rear-nonsticky text property lists. This works if
these are nil or lists, but they can also have the value t, meaning
that all properties are front-sticky/rear-nonsticky. In this case,
pushnew will signal an error because t is not a list. We never set
these properties to t ourselves, but since we apply these property
changes over arbitrary renderer output, we have to deal with this
possibility.
Several function docstrings refer to behaviour in docstrings that is
really controlled by notmuch-archive-tags. Add cross references, and
replace hardcoding.
These functions refer to default values of variables, but it seems
less confusing and less likely to get out of date to just allow the
user to follow the help cross-reference links.
I found several places where a setq is immediately followed by a let
or a let*. This seems to be the pessimal combination, with the
implicit scope of the setq combined with the extra indentation of the let.
I combined these cases into a single let* which I think is easier to read.
I can't see any benefit to the funcall, and it looks like the result
of cut-and-paste from some code that actually used a variable for the
function to call.
Since the part commands are no longer tied to a button, but can be
applied with point anywhere within a part, bind the part commands
keymap to "." everywhere in the show buffer. This lets you save or
view parts without having to navigate to the part button, and is
particularly useful for parts that have no button.
This removes the un-prefixed MIME part commands from the part button
keymap, but that's okay because those clashed in annoying ways with
show buffer bindings like "s" for search. RET on part buttons is
unaffected, which is the most important part button binding.
This unifies the part button actions and the underlying part action
functions into single interactive command that simply applies to the
part containing point using the just-added part p-list text property
instead of button properties. Since all part actions can be performed
by applying the appropriate mm function to an mm-handle, this patch
abstracts out the creation of mm handles, making the implementations
of the part commands trivial. This also eliminates our special
handling for part save in favor of using the appropriate mm function.
This necessarily modifies the way we handle the default part button
action, but in a way that does not change the meaning of the
notmuch-show-part-button-default-action defcustom.
Since these commands are no longer specific to buttons, this patch
eliminates the extra metadata stored with each button. This also
eliminates one rather special-purpose macro for a collection of
general purpose part handling utilities.
This is similar to what we already do with the message p-list, though
we apply the part's text property to the whole part's text, in
contrast with the message p-list, which is (rather obscurely) only
applied to the first character.
Previously, we lost any text properties applied to part buttons or
wash buttons when they were toggled because `insert' directly copies
the text properties of the string being inserted. Fix this by
capturing the properties applied to the button beforehand and
re-applying them after inserting the new text.
Previously, notmuch-show-view-part overrode the function binding of
mm-show-part to redirect it to notmuch-show-save-part to get notmuch's
default file name handling in case mm-display-part decided to fall
back to saving the part. In addition to being messy, this depended on
the now-deprecated dynamic binding behavior of flet.
This patch removes the mm-show-part override in favor of passing the
file name in to mm-show-part the way it expects, so we get its default
file name handling. It's not clear why we didn't do this before;
mm-show-part has supported default file names since at least Emacs
23.1.
Currently mime parts are basically handled based on their mime-type
with the exception of application/octet-stream parts. Deal with these
parts at the top level (notmuch-show-insert-bodypart).
This is needed later in the series as we need to put in a part button
for each part (which means knowing its mime type) while deferring the
actual insertion of the part.
Some (declare-function ...) definitions were drifted away from the
actual (defun ...)'s. To find the drifts and to verify changes
the following command line was used:
$ emacs --batch -L emacs --eval '(check-declare-directory "emacs")'
This patch extracts the rendering of tags in notmuch-show to
the notmuch-tag file.
This file introduces a `notmuch-tag-formats' variable that associates
each tag to a particular format. This variable can be customized
thanks to the work of Austin Clements. For example,
'(("unread" (propertize tag 'face '(:foreground "red")))
("flagged" (notmuch-tag-format-image tag "star.svg")))
associates a red foreground to the "unread" tag and a star picture to
the "flagged" tag.
Signed-off-by: Damien Cassou <damien.cassou@gmail.com>
Emacs has two button type objects: widgets (as used for saved searches
in notmuch-hello) and buttons as used by parts/citations and id links
in notmuch-show. These two behave subtly differently when clicked with
the mouse: widgets select the window clicked before running the
action, buttons do not.
This patch makes all of these behave the same: clicking always selects
the clicked window. It does this by defining a notmuch-button-type
supertype that the other notmuch buttons can inherit from. This
supertype binds the mouse-action to select the window and then
activate the button.
There is a bug in the current notmuch code with w3m and invisible
parts. w3m sets a keymap, and if we have a hidden [text/html] point
at the start of the following line still gets this w3m keymap which
causes some strange effects. For example, RET gives an error "No URL
at Point" rather than hiding the message, <down> goes to the next link
rather than just down a line.
These keybinding are also inconvenient when the text/html part is
displayed so we ask w3m not to install a keymap.
This is only likely to be a problem for emacs 23 as shr is preferred
as html renderer on emacs 24 (although the user can set the renderer
to w3m even on emacs 24).
This solution was suggested by Tomi Ollila <tomi.ollila@iki.fi>
Now that the invisibility display of parts is present we no longer
need to force the display of all multipart/alternatives: users can
toggle them for themselves when needed.
This adds a button action to show hidden parts. In this version "RET"
toggles the visibility of any part which puts content in the buffer
(as opposed to attachments such as application/pdf).
The button is used to hide parts when appropriate (eg text/html in
multipart/alternative).
This makes notmuch-show-insert-bodypart add an overlay for any
non-trivial part with a button header (currently the first text/plain
part does not have a button). At this point the overlay is available
to the button but there is no action using it yet.
In addition the argument HIDE is passed down to
notmuch-show-insert-part-overlays to request that the part be hidden
by default but this is not acted on yet.
This just make notmuch-show-insert-part-header save the basic button
text for parts as an attribute. This makes it simpler for the button
action (added in a later patch) to reword the label as appropriate (eg
append "(not shown)" or not as appropriate).
Previously, all visibility in show buffers for headers, message
bodies, and washed text was specified by generating one or more
symbols for each region and creating overlays with their 'invisible
property set to carefully crafted combinations of these symbols.
Visibility was controlled not by modifying the overlays directly, but
by adding and removing the generated symbols from a gigantic buffer
invisibilty spec.
This has myriad negative consequences. It's slow because Emacs'
display engine has to traverse the buffer invisibility list for every
overlay and, since every overlay has its own symbol, this makes
rendering O(N^2) in the number of overlays. It composes poorly
because symbol-type 'invisible properties are taken from the highest
priority overlay over a given character (which is often ambiguous!),
rather than being gathered from all overlays over a character. As a
result, we have to include symbols related to message hiding in the
wash code lest the wash overlays un-hide parts of hidden messages. It
also requires various workarounds for isearch to properly open
overlays, to set up buffer-invisibility-spec for
remove-from-invisibility-spec to work right, and to explicitly refresh
the display after updating the buffer invisibility spec.
None of this is necessary.
This patch converts show and wash to use simple boolean 'invisible
properties and to not use the buffer invisibility spec. Rather than
adding and removing generated symbols from the invisibility spec, the
code now directly toggles the 'invisible property of the appropriate
overlay. This speeds up rendering because the display engine only has
to check the boolean values of the overlays over a character. It
composes nicely because text will be invisible if *any* overlay over
it has 'invisible t, which means we can overlap invisibility overlays
with abandon. We no longer need any of the workarounds mentioned
above. And it fixes a minor bug for free: now, when isearch opens a
washed region, the button text will update to say "Click/Enter to
hide" rather than remaining unchanged.
Previously refreshing the notmuch show buffer did not remove overlays
which meant that if the user refreshed a message with images the
images would remain and then the new text was added after.
One might have guessed that erase-buffer would have removed them but
it seems not. Thus force the removal of overlays with remove-overlays.
This function is also used by pick so split it out in preperation for
moving to lib. In fact, pick and show want a slightly different
combination of name and email on return so make the separated function
return them as a pair, and let show or pick extract the combination
they want from that.
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.
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).
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.
This regexp agrees with Xapian query syntax much more closely, though
we specifically disallow various cases that would be confusing in the
context of an email body (e.g., punctuation at the end of an id: link
is not considered part of the id: link because it's probably part of
the surrounding text).
In particular, this handles id: links that are not surrounded by
quotes much better, which stash is much more likely to generate now
that we don't quote id's that don't need to be quoted. It also
handles quoted id: links better.
We update the buttonization test to reflect the new pattern.
When inserting of email bodypart failes, insert a failure message
to the buffer (and continue) instead of halting the insertion of
the rest of that email thread in question.
Since marking a message as read can now be a user customized set of
tag changes, make reversing this easier. Allow a prefix argument to
notmuch-show-mark-read to reverse the marking as read, similar to the
unarchiving in notmuch-show-archive-message.
While at it, update the relevant documentation to match that of other
automatic tagging (i.e. archive and reply).
Add support for customization of the tag changes that are applied when
a message or a thread is archived. Instead of hard-coded removal of
the "inbox" tag, the user can now specify a list of tag changes to
perform.
The `notmuch-show-mark-read-tags' lists tags that are to be applied when
message is read. By default, the only value is "-unread" which will remove
the unread tag. Among other uses, this variable can be used to stop
notmuch-show from modifying tags when message is shown (by setting the
variable to an empty list).
Previously, notmuch-show-previous-message would move to the beginning
of the message before the message containing point. This patch makes
it instead move to the previous message *boundary*. That is, if point
isn't already at the beginning of the message, it moves to the
beginning of the current message. This is consistent with
notmuch-show-next-message, which can be thought of as moving to the
next message boundary. Several people have expressed a preference for
this.
The pipe message function (when used with a prefix) uses a search of
the form "id:<id1> or id:<id2>" etc. Since the user says precisely
which messages are wanted by opening them it should not use excludes.
Previously the elide messages code got the entire-thread from
notmuch-show.c and then threw away all non-matching messages. This
version calls notmuch-show.c without the --entire-thread flag so
it never receives the non-matching messages in the first place.
This makes it substantially faster.
Allow the user to pipe the attachment somewhere. Bound to '|' on the
attachment button.
Signed-off-by: Jameson Graef Rollins <jrollins@finestructure.net>
Quote non-text parts nicely by displaying them with mm-display-part
before calling message-cite-original to quote them. HTML-only emails
can now be quoted correctly. We re-use some code from notmuch-show
(notmuch-show-mm-display-part-inline), which has been moved to
notmuch-lib.el.
Mark the test for this feature as not broken.
The main change here is to modify argument parsing so as to not force
tag-changes to be a list, and to let notmuch-tag handle prompting the
user when required. doc strings are also updated and cleaned up.
Tagging functions are used in notmuch.el, notmuch-show.el, and
notmuch-message.el. There are enough common functions for tagging
that it makes sense to put them all in their own library.
No code is modified, just moved around.
When using the spacebar to scroll through a thread, hitting 'space'
when the bottom of the last message is visible should take the cursor
to the end of the buffer rather than immediately archiving the thread
and moving to the next thread.
Currently emacs show does not open matching but excluded
messages. This is normally the desired behaviour but is probably not
ideal if only excluded messages match. This patch opens all the
matching (necessarily excluded) messages in this case and goes to the
first one.
A previous patch [0] replaced blank subject lines with '[No Subject]'
in search and show mode. Apparently this was needed to circumvent
some bug in the printing code, but there was no need for it search or
show, and it is definitely not desirable, so we undo it here (a revert
is no longer feasible). We should not be modifying strings in the
original message without good reason, or without a clear indication
that we are doing so, neither of which apply in this case. For
further discussion see [0].
[0] id:"1327918561-16245-3-git-send-email-dme@dme.org"
Show has to set --exclude=false to deal with cases where it is asked
to show a single excluded message. It uses JSON so it can easily pass
the exclude information to the user.
This adds a lib function to turn a message ID into a properly escaped
message ID query and uses this function wherever we previously
hand-constructed ID queries. Wherever this new function is used,
documentation has been clarified to refer to "id: queries" instead of
"message IDs".
This fixes the broken test introduced by the previous patch.
Use the new JSON reply format to create replies in emacs. Quote HTML
parts nicely by using mm-display-part to turn them into displayable
text, then quoting them with message-cite-original. This is very
useful for users who regularly receive HTML-only email.
Use message-mode's message-cite-original function to create the
quoted body for reply messages. In order to make this act like the
existing notmuch defaults, you will need to set the following in
your emacs configuration:
message-citation-line-format "On %a, %d %b %Y, %f wrote:"
message-citation-line-function 'message-insert-formatted-citation-line
The tests have been updated to reflect the (ugly) emacs default.
Show mode will recognize the exclude flag by not opening excluding
messages by default, and will start at the first matching non-excluded
message. If there are no matching non-excluded messages it will go to
the first matching (necessarily excluded) message.
It is not clear whether the term "thread" refers to the thread in the
database or to the thread currently shown in a buffer. Those two
meanings may refer to different sets of messages, e.g. when a new email
is added to the database while the buffer shows the state before the new
email arrived.
This patch replaces the term thread with the term current buffer, which
is hopefully less ambiguous.
The behavior of the header line in show-mode changed from showing the
subject of the first open message to showing the subject of the first
message in 4d77f18b. Update a comment to reflect this.
Consensus seems to be that people prefer that refreshing show buffers
retains state by default, rather than resetting it by default. This
turns out to be the case in the code, as well. In fact, there's even
a test for this that's been marked broken for several months, which
this patch finally gets to mark as fixed.
If we retain state while refreshing a show buffer, it should not mark
any messages read since it's not a navigation operation (it especially
shouldn't mark the first message matching the query read, which is
what it did previously). If the user or caller requests that refresh
reset the state of the buffer, then we consider that a navigation
operation, so we do mark the message under point after the refresh
read.
This is implemented by moving responsibility for initial positioning
and read-marking out of notmuch-show-worker and into its caller.
Since notmuch-show-worker is now exclusively about building the show
buffer, we rename it to notmuch-show-build-buffer.
* emacs/notmuch-show.el
(notmuch-show-stash-mlarchive-link-alist):
New defcustom of type `alist' (key = name, value = URI),
containing Mailing List Archive URI's for searching by Message-Id.
(notmuch-show-stash-mlarchive-link-default):
New defcustom, default MLA to use when `notmuch-show-stash-mlarchive-link'
received no user input whatsoever. Available choices are generated using
the contents of `notmuch-show-stash-mlarchive-link-alist'.
(notmuch-show-stash-map):
Added keybinds "l" and "L" for `notmuch-show-stash-mlarchive-link'
respectively `notmuch-show-stash-mlarchive-link-and-go'.
(notmuch-show-stash-mlarchive-link):
New function, stashes a URI pointing to the current message at one
of the MLAs configured in `notmuch-show-stash-mlarchive-link-alist'.
Prompts user with `completing-read' if not provided with an MLA key.
(notmuch-show-stash-mlarchive-link-and-go):
New function, uses `notmuch-show-stash-mlarchive-link' to
stash a URI, and then visits it using the browser configured
in `browse-url-browser-function'.
Based on original work [1] by David Edmondson <dme@dme.org>.
[1] id:"1327397873-20596-1-git-send-email-dme@dme.org"
* emacs/notmuch-show.el
(notmuch-show-get-message-id):
Add optional arg BARE. When non-nil, return a Message-Id without
quotes and prefix, thus obviating the need to strip them off again
in various places.
(notmuch-show-stash-message-id-stripped):
Update wrt changes in `notmuch-show-get-message-id'.
Replace text/x-vcalendar with text/calendar, while maintaining support
and backwards compatibility for text/x-vcalendar.
Code by David Edmondson <dme@dme.org>
The notmuch-show view refresh function (`notmuch-show-refresh-view',
bound to "=") accepts an optional RETAIN-STATE argument. The patch
allows to set this argument interactively by using "C-u =".
Recent changes in notmuch-show tagging introduced some code
duplication. The patch cleanups and simplifies
`notmuch-show-archive-thread' function by using
`notmuch-show-tag-all', no longer used function are removed. After
the change, `notmuch-show-archive-thread' function becomes symmetric
with `notmuch-show-archive-message'.
A side effect of these changes is that `notmuch-show-archive-thread'
no longer calls "notmuch tag" for each message in the thread.
With an argument, record and reply the state of the buffer during
`notmuch-show-refresh-view'.
In this context, "state" is defined as:
- the open/closed state of each message,
- the current message.
Traditional use of refresh with the = key does not retain the
state. The recently introduced toggle commands ($, !, < and >) do
retain the state.
Very deeply indented content is sometimes difficult to
read (particular for something like patches). Allow the indentation of
the content to be toggled with '<'.
Indentation of the header lines is not affected, so it remains
possible to see the structure of the thread.
The current behaviour (all messages shown, non-matching collapsed)
is retained as the default. Type '!' to switch to showing only
the matching messages - non-matching messages are not available.
'!' will switch back to showing everything.
Re-work the existing crypto switch toggle to be based on a persistant
buffer-local variable.
To allow this, modify `notmuch-show-refresh-view' to erase and re-draw
in the current buffer rather than killing the current buffer and
creating a new one. (This will also allow more per-buffer behaviour in
future patches.)
Add a binding ('$') to toggle crypto processing of the current buffer
and remove the prefix argument approach that achieves a similar
result.
Modify the show view key bindings as follows to make them more
consistent:
'a' = Archive current message, then move to next message, or show next
thread from search if at the last message in thread.
'A' = Archive each message in thread, then show next thread from
search.
'x' = Archive current message, then move to next message, or exit back
to search results if at the last message in thread.
'X' = Archive each message in thread, then exit back to search
results.
The changes make the key bindings more consistent in two ways:
1) 'a'/'A' both advance to the next thread like 'a' used to.
2) 'x' operates on messages and 'X' on threads like 'a'/'A'.
The patch adds `notmuch-show-tag-all' function bound to "*" in
notmuch-show view. The function is similar to the
`notmuch-search-tag-all' function for the notmuch-search view: it
changes tags for all messages in the current thread.
Before the change, "+" and "-" tagging operations in notmuch-show view
accepted only a single tag. The patch makes them use the recently
added `notmuch-read-tag-changes' function, which allows to enter
multiple tags with "+" and "-" prefixes. So after the change, "+" and
"-" bindings in notmuch-show view allow to both add and remove
multiple tags. The only difference between "+" and "-" is the
minibuffer initial input ("+" and "-" respectively).
The blank line doesn't really change position, but is now considered
to be part of the body rather than part of the headers. This means
that it is visible when the body is visible rather than when the
headers are visible.
This changes the default key bindings for the 'a' key in notmuch-show
mode. Instead of archiving the entire thread, it now just archives
the current message, and then advance to the next open message
(archive-message-then-next). 'A' is now bound to the previous
archive-thread-then-next function.