bug#16820: 24.3; nxml comment block indentation issue

[Nate Eagleson]

This bug report will be sent to the Bug-GNU-Emacs mailing list
and the GNU bug tracker at debbugs.gnu.org.  Please check that
the From: line contains a valid email address.  After a delay of up
to one day, you should receive an acknowledgment at that address.

Please write in English if possible, as the Emacs maintainers
usually do not have translators for other languages.

Please describe exactly what actions triggered the bug, and
the precise symptoms of the bug.  If you can, give a recipe
starting from `emacs -Q':

nxml-mode indents multiple lines in a comment block to match the
preceding line's indentation, even for blank lines. It should ignore
blank lines when determining indent level.

I couldn't find any mention of this bug in the mailing list archives,

which I searched with Google's site: feature, but I may have 

missed something.

To reproduce:

Start emacs with -Q.

Create a new buffer.

Start XML mode: M-x xml-mode

Enter the following text:

<test>
  <!-- This is a comment.

This is the next paragraph in the comment.
-->
</test>

Put the cursor before '-->' and press Tab. It will indent to the same
level as '<!--'.

Put the cursor before 'This is the next paragraph in the comment' and
press Tab. Nothing will happen.

Move up one line to the blank line. Press spacebar twice.

Move back down a line. Press Tab. The second line will now indent as
expected.

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
For information about debugging Emacs, please read the file
/Applications/Emacs.app/Contents/Resources/etc/DEBUG.


In GNU Emacs 24.3.1 (x86_64-apple-darwin, NS apple-appkit-1038.36)
of 2013-03-12 on bob.porkrind.org
Windowing system distributor `Apple', version 10.3.1038
Configured using:
`configure '--host=x86_64-apple-darwin' '--build=i686-apple-darwin'
'--with-ns' 'build_alias=i686-apple-darwin'
'host_alias=x86_64-apple-darwin' 'CC=gcc -mmacosx-version-min=10.5 ''

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: nXML

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
C-x C-f M-p n x <tab> <return> C-n C-n C-n <tab> C-/
M-x e m a <backspace> <backspace> <backspace> r e p
o <tab> <tab> o <tab> <backspace> r <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
user-error: Beginning of history; no preceding item
Using vacuous schema
Loading vc-git...done
Undo!
Making completion list...

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils help-mode vc-git nxml-uchnm rng-xsd xsd-regexp
rng-cmpct rng-nxml rng-valid rng-loc rng-uri rng-parse nxml-parse
rng-match rng-dt rng-util rng-pttrn nxml-ns easymenu nxml-mode
nxml-outln nxml-rap nxml-util nxml-glyph nxml-enc xmltok time-date
tooltip ediff-hook vc-hooks lisp-float-type mwheel ns-win tool-bar dnd
fontset image regexp-opt fringe tabulated-list newcomment lisp-mode
register page menu-bar rfn-eshadow timer select scroll-bar mouse
jit-lock font-lock syntax facemenu font-core frame cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
minibuffer loaddefs button faces cus-face macroexp files text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process ns multi-tty
emacs)

-Nate

http://www.nateeag.com