In Internet Explorer 8 (IE8) the 'blame_incremental' view, which uses
JavaScript to generate blame info using AJAX, sometimes hang at the
beginning (at 0%) of blaming, e.g. for larger files with long history
like git's own gitweb/gitweb.perl.

The error shown by JavaScript console is "Unspecified error" at char:2
of the following line in gitweb/gitweb.js:

  if (xhr.readyState === 3 && xhr.status !== 200) {

Debugging it using IE8 JScript debuger shown that the error occurs
when trying to access xhr.status (xhr is XMLHttpRequest object).
Watch for xhr object shows 'Unspecified error.' as "value" of
xhr.status, and trying to access xhr.status from console throws error.

This bug is some intermittent bug, depending on XMLHttpRequest timing,
as it doesn't occur in all cases.  It is probably caused by the fact
that handleResponse is called from timer (pollTimer), to work around
the fact that some browsers call onreadystatechange handler only once
for each state change, and not like required for 'blame_incremental'
as soon as new data is available from server.  It looks like xhr
object is not properly initialized; still it is a bug to throw an
error when accessing xhr.status (and not use 'null' or 'undefined' as
value).

Work around this bug in IE8 by using try-catch block when accessing
xhr.status.
Signed-off-by: NJakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It seems that in Firefox-3.5 inserting   with javascript inserts the
literal   instead of a space. Fix this by inserting the unicode
representation for   instead.

Also fix the off-by-one error in the padding calculation that was
causing one less space to be inserted than was requested by the caller.
Signed-off-by: NStephen Boyd <bebarino@gmail.com>
Cc: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Internet Explorer 8 stops at beginning of blame filling with the
following bug:

  "firstChild is null or not an object"

at this line:

  a_sha1.firstChild.data = commit.sha1.substr(0, 8);

It is (probably) caused by the fact that while a_sha1 element, which
looks like this:

  <a href=""> </a>

It has a firstChild which is a text node containing only whitespace
(single space character) in other web browsers (Firefox 3.5, Opera 10,
Google Chrome 3.0), IE8 clobbers DOM, removing trailing/leading
whitespace.

Protect against this bug by creating text element if it does not
exist.
Found-by: NStephen Boyd <bebarino@gmail.com>
Signed-off-by: NJakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Currently handleLine() assumes that a commit author name will always
start with a capital letter. It's possible that the author name is
user@example.com and therefore calling a match() on the name will fail
to return any matches. Subsequently joining these matches will cause an
exception. Fix by checking that we have a match before trying to join
the results into a set of initials for the author.
Signed-off-by: NStephen Boyd <bebarino@gmail.com>
Acked-by: NJakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The new 'blame_incremental' view requires JavaScript to run.  Not all
web browsers implement JavaScript (e.g. text browsers such as Lynx),
and not all users have JavaScript enabled.  Therefore instead of
unconditionally linking to 'blame_incremental' view, we use JavaScript
to convert those links to lead to view utilizing JavaScript, by adding
'js=1' to link.

Currently the only action that takes 'js=1' into account is 'blame',
which then acts as if it was called as 'blame_incremental' action.
Possible enhancement would be to do JavaScript redirect by setting
window.location instead of modifying $format and $action in
git_blame_common() subroutine.

The only JavaScript-aware/using view is currently 'blame_incremental'.
While at it move reading JavaScript to git_footer_html() subroutine.
Note that in this view we do not add 'js=1' currently (even though
perhaps we should; note that for consistency we should also add 'js=1'
in links added by JavaScript part of 'blame_incremental').

This idea was originally implemented by Petr Baudis in
  http://article.gmane.org/gmane.comp.version-control.git/47614
but it added <script> element with fixBlameLinks() function in page
header, to be added as onload event using 'onload' attribute of HTML
'body' element: <body onload="fixBlameLinks();">.  This version adds
script at then end of page (in the page footer), and uses JavaScript
'window.onload=fixLinks();'.  Also in Petr version only links marked
with 'blamelink' class were modified, and they were modified by
replacing "a=blame" by "a=blame_incremental"... which doesn't work for
path_info links, and might replace wrong part if there is "a=blame" in
project name, ref name or file name.

Slightly different solution was implemented by Martin Koegler in
  http://thread.gmane.org/gmane.comp.version-control.git/47902/focus=47905
Here GitAddLinks() function was in gitweb.js file, not as contents of
<script> element.  It was also included in page header (in <head>
element) though, which means waiting for a script to load (and run).
It was smarter in that to "fix" (modify) link, it split URL, modified
value of 'a' parameter, and then recreated modified link.  It avoids
trouble with "a=blame" as substring in project name or file name, but
it doesn't work with path_info URL/link in the way it was written.
Signed-off-by: NJakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This requires using 3 colors, not only two, to choose a color that is
different from colors of up to 2 neighbors.

gitweb.js selects the least used color, if more than one color is
possible.
Signed-off-by: NJakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add 'blame_incremental' view, which uses "git blame --incremental"
and JavaScript (Ajax), where 'blame' use "git blame --porcelain".

 * gitweb generates initial info by putting file contents (from
   "git cat-file") together with line numbers in blame table
 * then gitweb makes web browser JavaScript engine call startBlame()
   function from gitweb.js
 * startBlame() opens XMLHttpRequest connection to 'blame_data' view,
   which in turn calls "git blame --incremental" for a file, and
   streams output of git-blame to JavaScript (gitweb.js)
 * XMLHttpRequest event handler updates line info in blame view as soon
   as it gets data from 'blame_data' (from server), and it also updates
   progress info
 * when 'blame_data' ends, and gitweb.js finishes updating line info,
   it fixes colors to match (as far as possible) ordinary 'blame' view,
   and updates information about how long it took to generate page.

Gitweb deals with streamed 'blame_data' server errors by displaying
them in the progress info area (just in case).

The 'blame_incremental' view tries to be equivalent to 'blame' action;
there are however a few differences in output between 'blame' and
'blame_incremental' view:

 * 'blame_incremental' always used query form for this part of link(s)
   which is generated by JavaScript code.  The difference is visible
   if we use path_info link (pass some or all arguments in path_info).
   Changing this would require implementing something akin to href()
   subroutine from gitweb.perl in JavaScript (in gitweb.js).
 * 'blame_incremental' always uses "rowspan" attribute, even if
   rowspan="1".  This simplifies code, and is not visible to user.
 * The progress bar and progress info are still there even after
   JavaScript part of 'blame_incremental' finishes work.

Note that currently no link generated by gitweb leads to this new view.

This code is based on patch by Petr Baudis <pasky@suse.cz> patch, which
in turn was tweaked up version of Fredrik Kuivinen <frekui@gmail.com>'s
proof of concept patch.

This patch adds GITWEB_JS compile configuration option, and modifies
git-instaweb.sh to take gitweb.js into account.  The code for
git-instaweb.sh was taken from Pasky's patch.
Signed-off-by: NFredrik Kuivinen <frekui@gmail.com>
Signed-off-by: NPetr Baudis <pasky@suse.cz>
Signed-off-by: NJakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>