prefixcmp() and suffixcmp() share the common "cmp" suffix that
typically are used to name functions that can be used for ordering,
but they can't, because they are not antisymmetric:

        prefixcmp("foo", "foobar") < 0
        prefixcmp("foobar", "foo") == 0

We in fact do not use these functions for ordering.  Replace them
with functions that just check for equality.

Add starts_with() and end_with() that will be used to replace
prefixcmp() and suffixcmp(), respectively, as the first step.  These
are named after corresponding functions/methods in programming
languages, like Java, Python and Ruby.

In vcs-svn/fast_export.c, there was already an ends_with() function
that did the same thing. Let's use the new one instead while at it.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Humanization of downloaded size is done in the same function as text
formatting in 'process.c'. The code cannot be reused easily elsewhere.

Separate text formatting from size simplification and make the
function public in strbuf so that it can easily be used by other
callers.

We now can use strbuf_humanise_bytes() for both downloaded size and
download speed calculation. One of the drawbacks is that speed will
now look like this when download is stalled: "0 bytes/s" instead of
"0 KiB/s".

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Some users do want to write a line that begin with a pound sign, #,
in their commit log message.  Many tracking system recognise
a token of #<bugid> form, for example.

The support we offer these use cases is not very friendly to the end
users.  They have a choice between

 - Don't do it.  Avoid such a line by rewrapping or indenting; and

 - Use --cleanup=whitespace but remove all the hint lines we add.

Give them a way to set a custom comment char, e.g.

    $ git -c core.commentchar="%" commit

so that they do not have to do either of the two workarounds.

[jc: although I started the topic, all the tests and documentation
updates, many of the call sites of the new strbuf_add_commented_*()
functions, and the change to git-submodule.sh scripted Porcelain are
from Ralf.]

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Update imap-send to reuse xml quoting code from http-push codepath,
clean up some code, and fix a small bug.

* mh/unify-xml-in-imap-send-and-http-push:
  wrap_in_html(): process message in bulk rather than line-by-line
  wrap_in_html(): use strbuf_addstr_xml_quoted()
  imap-send: change msg_data from storing (ptr, len) to storing strbuf
  imap-send: correctly report errors reading from stdin
  imap-send: store all_msgs as a strbuf
  lf_to_crlf(): NUL-terminate msg_data::data
  xml_entities(): use function strbuf_addstr_xml_quoted()
  Add new function strbuf_add_xml_quoted()

Substantially the same code is present in http-push.c and imap-send.c,
so make a library function out of it.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

The word "delimiter" suggests that the argument separates the
substrings, whereas in fact (1) the delimiter characters are included
in the output, and (2) if the input string ends with the delimiter,
then the output does not include a final empty string.  So rename the
"delim" arguments of the strbuf_split() family of functions to
"terminator", which is more suggestive of how it is used.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>

While iterating, update str and slen to keep track of the part of the
string that hasn't been processed yet rather than computing things
relative to the start of the original string.  This eliminates one
local variable, reduces the scope of another, and reduces the amount
of arithmetic needed within the loop.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>

Use ALLOC_GROW() rather than inline code to manage memory in
strbuf_split_buf().  Rename "pos" to "nr" because it better describes
the use of the variable and it better conforms to the "ALLOC_GROW"
idiom.

Also, instead of adding a sentinal NULL value after each entry is
added to the list, only add it once after all of the entries have been
added.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>

* jk/strbuf-detach-always-non-null:
  strbuf: always return a non-NULL value from strbuf_detach

The current behavior is to return NULL when strbuf did not
actually allocate a string. This can be quite surprising to
callers, though, who may feed the strbuf from arbitrary data
and expect to always get a valid value.

In most cases, it does not make a difference because calling
any strbuf function will cause an allocation (even if the
function ends up not inserting any data). But if the code is
structured like:

  struct strbuf buf = STRBUF_INIT;
  if (some_condition)
	  strbuf_addstr(&buf, some_string);
  return strbuf_detach(&buf, NULL);

then you may or may not return NULL, depending on the
condition. This can cause us to segfault in http-push
(when fed an empty URL) and in http-backend (when an empty
parameter like "foo=bar&&" is in the $QUERY_STRING).

This patch forces strbuf_detach to allocate an empty
NUL-terminated string when it is called on a strbuf that has
not been allocated.

I investigated all call-sites of strbuf_detach. The majority
are either not affected by the change (because they call a
strbuf_* function unconditionally), or can handle the empty
string just as easily as NULL.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>